ElShamah - Reason & Science: Defending ID and the Christian Worldview
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ElShamah - Reason & Science: Defending ID and the Christian Worldview

Otangelo Grasso: This is my library, where I collect information and present arguments developed by myself that lead, in my view, to the Christian faith, creationism, and Intelligent Design as the best explanation for the origin of the physical world.


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The earth's atmosphere

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The earth's  atmosphere

https://reasonandscience.catsboard.com/t1556-the-earth-s-atmosphere

ASTRONOMICAL ORIGINS OF LIFE Steps Towards Panspermia Edited by F. HOYLE and N.e. WICKRAMASINGHE  page 105
The oldest surviving rocks have oxidation states that are indicative of an oxidising rather than a reducing atmosphere, at any rate at the time when the rocks condensed. 

The oxidation state of Hadean magmas and implications for early Earth’s atmosphere
1 DECEMBER 2011
Selected Hadean zircons (having chemical characteristics consistent with crystallization specifically from mantle-derived melts) suggest oxygen fugacities similar to those of Archaean and present-day mantle-derived lavas as early as ~4,350 Myr before present. These results suggest that outgassing of Earth’s interior later than ~200 Myr into the history of Solar System formation would not have resulted in a reducing atmosphere.
http://sci-hub.ren/https://www.nature.com/articles/nature10655

Leslie Orgel wrote:
Recent investigations indicate the earth's atmosphere was never as reducing as Urey and Miller presumed. 7

Precambrian atmospheric oxygen: evidence in the sedimentary distributions of carbon, sulfur, uranium, and iron
12 April 1976

In general, we find no evidence in the sedimentary distributions of carbon, sulfur, uranium, or iron, that an oxygen-free atmosphere has existed at any time during the span of geological history recorded in well preserved sedimentary rocks. 8

‘the sedimentary distributions of carbon, sulfur, uranium, and ferric and ferrous iron depend greatly upon ambient oxygen pressure and should reflect any major change in proportion of oxygen in the atmosphere or hydrosphere. The similar distributions of these elements in sedimentary rocks of all ages are here interpreted to indicate the existence of a Precambrian atmosphere containing much oxygen.’

‘we know of no evidence which proves orders-of-magnitude differences between Middle Archaean and subsequent atmospheric compositions, hydrospheric compositions, or total biomasses.’

A non-hostile climate was prerequisite for the evolution of life as we know it. Was there liquid water? Was there crust on which life could take hold? Earth’s habitable surface today is certainly different than it was 4.6 Bya when it first condensed out of our Sun’s dusty, rotating nebula. We have very little remaining evidence of Earth’s crust during its first 500 million years — just a handful of hardy zircon grains from the Jack Hills conglomerate in western Australia. Despite their tiny size, locked within each zircon’s crystal lattice is a remarkable record of events back 4.4 Bya. Their chemistry, detected by ion beams just a few microns wide, suggest they formed as part of buoyant crust and in the presence of liquid water.  9

The earth's  atmosphere   JvPeuYx

We live in a unique environment.  Earth is the only planet we know of that has an oxygen-rich atmosphere, as well as a hydrosphere, and both oceanic and continental crust, which combine to sustain complex life 4

The assumption of an oxygen-free atmosphere has also been rejected on theoretical grounds. The ozone layer around planet earth consists of a thin but critical blanket of oxygen gas in the upper atmosphere. This layer of oxygen gas blocks deadly levels of ultraviolet radiation from the sun. Without oxygen in the early atmosphere, there could have been no ozone layer over that early earth. Without an ozone layer, all life on the surface of planet earth would face certain death from exposure to intense ultraviolet radiation. Furthermore, the chemical building blocks of proteins, RNA and DNA, would be quickly annihilated because ultraviolet radiation destroys their chemical bonds. It doesn't matter if these newly formed building blocks are in the atmosphere, on dry ground, or under water.  1

 So we have a major dilemma. The products of the Miller-Urey experiments would be destroyed if oxygen was present, and they would be destroyed if it wasn't! This "catch 22" has been noted by evolutionist and molecular biologist Michael Denton:

"What we have then is a sort of 'Catch 22' situation. If we have oxygen we have no organic compounds, but if we don't we have none either."

Even if the building blocks of life could survive the effects of intense ultraviolet radiation and form life spontaneously, the survival of any subsequent life forms would be very doubtful in the presence of such heavy ultraviolet light. Ozone must be present to protect any surface life from the deadly effects of ultraviolet radiation from the sun.


The Earth’s Atmospheric Conditions Are Favorable to Life:
The surface gravity of Earth is critical to its ability to retain an atmosphere friendly to life. If Earth’s gravity were stronger, our atmosphere would contain too much methane and ammonia. If our planet’s gravity were weaker, Earth wouldn’t be able to retain enough water. As it is, Earth’s atmosphere has a finely calibrated ratio of oxygen to nitrogen—just enough carbon dioxide and adequate water vapor levels to promote advanced life, allow photosynthesis (without an excessive greenhouse effect), and to allow for sufficient rainfall. 2

Our atmosphere contains the right proportions of gases that are absolutely essential for life. Some of those gases, by themselves, are deadly. But because air contains safe proportions of these gases, we can breathe them without harm.


Visible light is also incredibly fine-tuned for life to exist
Though visible light is only a tiny fraction of the total electromagnetic spectrum coming from the sun, it happens to be the "most permitted" portion of the sun's spectrum allowed to filter through the our atmosphere. All the other bands of electromagnetic radiation, directly surrounding visible light, happen to be harmful to organic molecules, and are almost completely absorbed by the atmosphere. The tiny amount of harmful UV radiation, which is not visible light, allowed to filter through the atmosphere is needed to keep various populations of single cell bacteria from over-populating the world (Ross; reasons.org). The size of light's wavelengths and the constraints on the size allowable for the protein molecules of organic life, also seem to be tailor-made for each other. This "tailor-made fit" allows photosynthesis, the miracle of sight, and many other things that are necessary for human life. These specific frequencies of light (that enable plants to manufacture food and astronomers to observe the cosmos) represent less than 1 trillionth of a trillionth (10^-24) of the universe's entire range of electromagnetic emissions. Like water, visible light also appears to be of optimal biological utility (Denton; Nature's Destiny).

Distance of the earth from the sun : Malcolm Bowden says, "If it were 5% closer, then the water would boil up from the oceans and if it were just 1% farther away, then the oceans would freeze, and that gives you just some idea of the knife edge we are on."

The carbon dioxide level in atmosphere  If greater: runaway greenhouse effect would develop.  If less: plants would be unable to maintain efficient photosynthesis

Oxygen quantity in atmosphere If greater: plants and hydrocarbons would burn up too easily.  If less: advanced animals would have too little to breathe

Nitrogen quantity in atmosphere If greater: too much buffering of oxygen for advanced animal respiration; too much nitrogen fixation for support of diverse plant species.  
If less: too little buffering of oxygen for advanced animal respiration; too little nitrogen fixation for support of diverse plant species.

Atmospheric pressure: If too small: liquid water will evaporate too easily and condense too infrequently; weather and climate variation would be too extreme; lungs will not function. If too large: liquid water will not evaporate easily enough for land life; insufficient sunlight reaches planetary surface; insufficient uv radiation reaches planetary surface; insufficient climate and weather variation; lungs will not function

Atmospheric transparency:If smaller: insufficient range of wavelengths of solar radiation reaches the planetary surface. If greater: too broad a range of wavelengths of solar radiation reaches planetary surface

stratospheric ozone quantity:If smaller: too much uv radiation reaches planet’s surface causing skin cancers and reduced plant growth . If larger: too little uv radiation reaches planet’s surface causing reduced plant growth and insufficient vitamin production for animals


The Oxygen Problem
http://xwalk.ca/origin.html
    The atmospheric conditions proposed by Oparin, Haldane and Urey were radically different from what presently exists. Because oxygen destroys the chemical building blocks of life, they speculated that the early earth had an oxygen-free atmosphere. 

However, in the last twenty years, evidence has surfaced that has convinced most atmospheric scientists that the early atmosphere contained abundant oxygen.

    In the 1970's Apollo 16 astronauts discovered that water is broken down into oxygen and hydrogen gas in the upper atmosphere when it is bombarded by ultraviolet radiation. This process, called photo dissociation, is an efficient process which would have resulted in the production of large quantities of oxygen in a relatively short time. Studies by the astronauts revealed that this process is probably a major source of oxygen in our current atmosphere. 2 H2O + uv Radiation -- H2 (hydrogen gas) + O2 (oxygen gas)

    The assumption of an oxygen-free atmosphere has also been rejected on theoretical grounds. The ozone layer around planet earth consists of a thin but critical blanket of oxygen gas in the upper atmosphere. This layer of oxygen gas blocks deadly levels of ultraviolet radiation from the sun.9 Without oxygen in the early atmosphere, there could have been no ozone layer over that early earth. Without an ozone layer, all life on the surface of planet earth would face certain death from exposure to intense ultraviolet radiation. Furthermore, the chemical building blocks of proteins, RNA and DNA, would be quickly annihilated because ultraviolet radiation destroys their chemical bonds.10 It doesn't matter if these newly formed building blocks are in the atmosphere, on dry ground, or under water.11,12,13

    So we have a major dilemma. The products of the Miller-Urey experiments would be destroyed if oxygen was present, and they would be destroyed if it wasn't! This "catch 22" has been noted by evolutionist and molecular biologist Michael Denton:

    "What we have then is a sort of 'Catch 22' situation. If we have oxygen we have no organic compounds, but if we don't we have none either."

    Even if the building blocks of life could survive the effects of intense ultraviolet radiation and form life spontaneously, the survival of any subsequent life forms would be very doubtful in the presence of such heavy ultraviolet light. Ozone must be present to protect any surface life from the deadly effects of ultraviolet radiation from the sun.


   Finally, the assumption that there was no oxygen in the early atmosphere is not borne out by the geologic evidence. Geologists have discovered evidence of abundant oxygen content in the oldest known rocks on earth.

Again, Michael Denton:

    "Ominously, for believers in the traditional organic soup scenario, there is no clear geochemical evidence to exclude the possibility that oxygen was present in the Earth's atmosphere soon after the formation of its crust."

    All of this evidence supports the fact that there was abundant oxygen on the early earth.

Ammonia and Methane Short Lived

    The assumption of an atmosphere consisting mainly of ammonia, methane, and hydrogen, has also been seriously questioned. In the 1970's scientists concluded that ultraviolet radiation from the sun, as well as simple "rainout," would eliminate ammonia and methane from the upper atmosphere in a very short time.16 In 1981, Atmospheric scientists from NASA concluded that:

    "the methane and ammonia-dominated atmosphere would have been very short lived if it ever existed at all."


http://bio-complexity.org/ojs/index.php/main/article/view/BIO-C.2013.1/BIO-C.2013.1
if atmospheric levels of oxygen rise much above 21%, spontaneous combustion of carbon compounds becomes an increasing danger [22: p. 34]. The fact that oxygen levels sufficient to support high levels of metabolism by air-breathing organisms do not at the same time support spontaneous conflagrations is clearly a coincidence of great relevance for terrestrial life.

http://adsabs.harvard.edu/abs/2004NCimC..27...99F
The details on the origin of nitrogen, which exists so abundantly in the Earth's atmosphere, are missing.

The name originates from the Greek Nitron and the Latin word nitrum meaning "genes" and "forming".
http://www.bestbiblescience.org/ol1.htm

Our current atmosphere consists primarily of oxygen (21%) and nitrogen (78%) and is called oxidizing because of chemical reactions produced by oxygen. For example, iron is oxidized to form iron oxide or rust.

The presence of oxygen in a hypothetical primordial atmosphere poses a difficult problem for notions of self-assembling molecules. If oxygen is present, there would be no amino acids, sugars, purines, etc. Amino acids and sugars react with oxygen to form carbon dioxide (CO2) and water.

Because it is impossible for life to evolve with oxygen, evolutionists theorize an early atmosphere without oxygen. This departs from the usual evolutionary theorizing where a uniformistic view is held (i.e. where processes remain constant over vast stretches of time). In this case the present is NOT the key to the past.

Instead, they propose a "reducing" (called thus because of the chemical reactions) atmosphere which contains free hydrogen. Originally, they postulated an atmosphere consisting of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), ammonia (NH3), free hydrogen and water vapor. Newer schemes exclude ammonia and methane.

There is a problem if you consider the ozone (O3) layer which protects the earth from ultraviolet rays. Without this layer, organic molecules would be broken down and life would soon be eliminated. But if you have oxygen, it prevents life from starting. A "catch-22" situation (Denton 1985, 261-262):

   Atmosphere with oxygen => No amino acids => No life possible!
   Atmosphere without oxygen => No ozone => No life possible!

In must be noted at this point that the existence of a reducing atmosphere is theoretical and does not rely on physical evidence. To the contrary, there are geological evidence for the existence of an oxidizing atmosphere as far back as can be determined. Among these are the precipitation of limestone (calcium carbonate) in great quantities, the oxidation of ferrous iron in early rocks (Gish 1972, 8)and the distribution of minerals in early sedimentary rocks (Gish 1984T).

http://www.livescience.com/39938-earth-had-oxygen-earlier.html
Oxygen may have filled Earth's atmosphere hundreds of millions of years earlier than previously thought, suggesting that sunlight-dependent life akin to modern plants evolved very early in Earth's history, a new study finds.

The findings, detailed in the Sept. 26 issue of the journal Nature, have implications for extraterrestrial life as well, hinting that oxygen-generating life could arise very early in a planet's history and potentially suggest even more worlds could be inhabited around the universe than previously thought, the study's authors said.

It was once widely assumed that oxygen levels remained low in the atmosphere for about the first 2 billion years of Earth's 4.5-billion-year history. Scientists thought the first time oxygen suffused the atmosphere for any major length of time was about 2.3 billion years ago in what is called the Great Oxidation Event. This jump in oxygen levels was almost certainly due to cyanobacteria — microbes that, like plants, photosynthesize and exhale oxygen.

However, recent research examining ancient rock deposits had suggested that oxygen may have transiently existed in the atmosphere 2.6 billion to 2.7 billion years ago.

The new study pushes this boundary back even further, suggesting Earth's atmosphere became oxygenated about 3 billion years ago, more than 600 million years before the Great Oxidation Event. In turn, this suggests that something was around on the planet to put that oxygen in the atmosphere at this time.

"The fact oxygen is there requires oxygenic photosynthesis, a very complex metabolic pathway, very early in Earth's history," said researcher Sean Crowe, a biogeochemist at the University of British Columbia in Vancouver. "That tells us it doesn't take long for biology to evolve very complex metabolic capabilities." [7 Theories on the Origin of Life]

Ancient oxygen reactions

Crowe and his colleagues analyzed levels of chromium and other metals in samples from South Africa that could serve as markers of reactions between atmospheric oxygen and minerals in Earth's rocks. They looked at both samples of ancient soil and marine sediments from about the same time period — 3 billion years ago.

The researchers focused on the different levels of chromium isotopes within their samples. Isotopes are variants of elements; all isotopes of an element have the same number of protons in their atoms, but each has a different number of neutrons — for instance, each atom of chromium-52 has 28 neutrons, while atoms of chromium-53 have 29.

When atmospheric oxygen reacts with rock — a process known as weathering —heavier chromium isotopes, such as chromium-53, often get washed out to sea by rivers. This means heavier chromium isotopes are often depleted from soils on land and enriched in sediments in the ocean when oxygen is around. These proportions of heavier chromium were just what were seen in the South African samples. Similar results were seen with other metals, such as uranium and iron, that hint at the presence of oxygen in the atmosphere.

"We now have the chemical tools to detect trace atmospheric gases billions of years ago," Crowe told LiveScience.

'Almost certainly biological'

All in all, the researchers suggest atmospheric oxygen levels 3 billion years ago were about 100,000 times higher than what can be explained by regular chemical reactions in Earth's atmosphere. "That suggests the source of this oxygen was almost certainly biological," Crowe said.

"It's exciting that it took a relatively short time for oxygenic photosynthesis to evolve on Earth," Crowe added. "It means that it could happen on other planets on Earth, expanding the number of worlds that could've developed oxygenated atmospheres and complex oxygen-breathing life."

Future research can look for similarly aged rocks from other places, both on and outside Earth, to confirm these findings. "Research could also look at earlier rocks," Crowe said. "Chances are, if there was oxygen 3 billion years ago, there was likely oxygen production sometime before as well. How far back does it go?"


http://www.scientificamerican.com/article/origin-of-oxygen-in-atmosphere/
"What it looks like is that oxygen was first produced somewhere around 2.7 billion to 2.8 billion years ago. It took up residence in atmosphere around 2.45 billion years ago," says geochemist Dick Holland, a visiting scholar at the University of Pennsylvania. "It looks as if there's a significant time interval between the appearance of oxygen-producing organisms and the actual oxygenation of the atmosphere."

So a date and a culprit can be fixed for what scientists refer to as the Great Oxidation Event, but mysteries remain. What occurred 2.45 billion years ago that enabled cyanobacteria to take over? What were oxygen levels at that time? Why did it take another one billion years—dubbed the "boring billion" by scientists—for oxygen levels to rise high enough to enable the evolution of animals?

Most important, how did the amount of atmospheric oxygen reach its present level? "It's not that easy why it should balance at 21 percent rather than 10 or 40 percent," notes geoscientist James Kasting of Pennsylvania State University. "We don't understand the modern oxygen control system that well."

http://www.dailytech.com/Scientists+Show+Evidence+of+How+Earth+Got+Its+Oxygen/article31853.htm
Researchers even have a good idea of where algae got their photosynthesis genes.  Describes geobiology Professor Woodward Fischer of the California Institute of Technology (CalTech), "Water-oxidizing or water-splitting photosynthesis was invented by cyanobacteria approximately 2.4 billion years ago and then borrowed by other groups of organisms thereafter.  Algae borrowed this photosynthetic system from cyanobacteria, and plants are just a group of algae that took photosynthesis on land, so we think with this finding we're looking at the inception of the molecular machinery that would give rise to oxygen."

http://www.reasonablefaith.org/the-teleological-argument-and-the-anthropic-principle
For example, CO2 has the property, unique among gases, of having at ordinary temperatures about the same concentration of molecules per unit volume in water as in air. This enables CO2 to undergo perpetual exchange between living organisms and their environment so that it is everywhere available for photosynthesis and thereby for molecular synthesis. The element N, on the other hand, is a rare element on Earth, but it does makeup 80% of the earth's atmosphere, which is a unique stroke of fortune for Earth's living organisms.

The reason for the abundance of oxygen in the atmosphere is the presence of a very large number of organisms which produce oxygen as a byproduct of their metabolism.// that's exactly right. These organisms are called cyanobacteria. And their capabilities are nothing more than astounding. They are one of the oldest bacteria that live on earth, estimates in scientific literature are 3 to 3,5 billion years. No cyanobacteria, no oxygen, no higher life forms. These cyanobacteria have incredibly sophisticated enzyme proteins and metabolic pathways, like the electron transport chains in photosynthesis, ATP synthase motors, circadian clock, the photosynthetic light reactions, carbon concentration mechanism, and transcriptional regulation, they produce binded nitrogen through nitrogenase, a highly sophisticated mechanism to bind nitrogen, used as a nutrient for plant and animal growth. The Nitrogen cycle is a lot more complex than the carbon cycle. Nitrogen is a very important element. It makes up almost 80% of our atmosphere, and it is an important component of proteins and DNA, both of which are the building blocks of animals and plants. Therefore without nitrogen, we would lose one of the most important elements on this planet, along with oxygen, hydrogen, and carbon. There are a number of stages to the nitrogen cycle, which involve breaking down and building up nitrogen and it’s various compounds.There is no real starting point for the nitrogen cycle. It is an endless cycle.Potential gaps in the system cannot be reasonably bypassed by inorganic nature alone.It must have a degree of specificity that in all probability could not have been produced by chance. A given function or step in the system may be found in several different unrelated organisms. The removal of any one of the individual biological steps will resort in the loss of function of the system. The data suggest that the nitrogen cycle may be irreducibly interdependent based on the above criteria. No proposed neo-Darwinian mechanisms can explain the origin of such a system.Without cyanobacteria - no fixed nitrogen is available.Without fixed nitrogen, no DNA, no amino-acids, no protein can be synthesized.Without DNA, no amino-acids, protein, or cyanobacteria are possible. So that's an interdependent system.

New study: Oxygenic photosynthesis goes back three billion years

http://www.uncommondescent.com/intelligent-design/new-study-oxygenic-photosynthesis-goes-back-three-billion-years/

An international team of scientists has published an article in Nature magazine, suggesting that oxygen began accumulating in the atmosphere at least three billion years ago. The team’s findings raise a troubling question for Darwinian evolutionists: how did the exquisitely complex metabolism of oxygenic photosynthesis arise so soon after the dawn of life?

An oxygen concentration of 0.03% might not sound like much, but it’s at least 10 times higher than most scientists had previously expected. As the Nature article explains, the new finding radically revises the old picture:

   It is widely assumed that atmospheric oxygen concentrations remained persistently low (less than 10^−5 [0.00001] times present levels) for about the first 2 billion years of Earth’s history. The first long-term oxygenation of the atmosphere is thought to have taken place around 2.3 billion years ago, during the Great Oxidation Event. Geochemical indications of transient atmospheric oxygenation, however, date back to 2.6–2.7 billion years ago… Overall, our findings suggest that there were appreciable levels of atmospheric oxygen about 3 billion years ago, more than 600 million years before the Great Oxidation Event and some 300–400 million years earlier than previous indications for Earth surface oxygenation. (Square brackets mine – VJT.)

When did oxygenic photosynthesis evolve?


Cyanobacteria (pictured above), also known as blue-green bacteria, are believed to have been the earliest organisms to engage in oxygenic photosynthesis, as plants and algae do. Under aerobic conditions, cyanobacteria are capable of performing the process of water-oxidizing photosynthesis by coupling the activity of two protein complexes, known as photosystem (PS) II and I, in a chain of events known as the Z-scheme. These protein complexes are located in the thylakoid (“pouch-like”) membrane of plants, algae, and cyanobacteria. The diagrams below illustrate what’s going on. First, here’s a schematic diagram, showing what a humble cyanobacterium looks like on the inside. The thylakoid membrane is shown in the diagram:

The ozone-oxygen cycle is the process by which ozone is continually regenerated in the Earth's stratosphere, all the while converting ultraviolet radiation (UV) into heat.
Most of the ozone production occurs in the tropical upper stratosphere and mesosphere. The total mass of ozone produced per day over the globe is about 400 million metric tons. The global mass of ozone is relatively constant at about 3 billion metric tons, meaning the Sun produces about 12% of the ozone layer each day.Ozone plays a beneficial role by absorbing most of the biologically damaging ultraviolet sunlight (called UV-B), allowing only a small amount to reach the Earth's surface. Ozone thus plays a key role in the temperature structure of the Earth's atmosphere. Without the filtering action of the ozone layer, more of the Sun's UV-B radiation would penetrate the atmosphere and would reach the Earth's surface.
In the atmosphere, Oxygen is freed by the process called photolysis. This is when high energy sunlight breaks apart oxygen-bearing molecules to produce free oxygen. One of the most well-known photolysis it the ozone cycle. O2 oxygen molecule is broken down to atomic oxygen by the ultraviolet radiation of sunlight. This free oxygen then recombines with existing O2 molecules to make O3 or ozone. This cycle is important because it helps to shield the Earth from the majority of harmful ultraviolet radiation turning it to harmless heat before it reaches the Earth’s surface.
The longer ultraviolet waves that penetrate the ozone layer are responsible for sunburn and suntan, skin cancers. They are also essential to good health, since they cause vitamin D to be formed in the body, and help in the accumulation of calcium and phosphorus. All of these substances are vital to the formation and maintenance of healthy teeth and bones.
The Rise of Oxygen - 2400 million years ago

All air-breathing life on Earth depends on the energy produced by the respiration of carbon compounds (i.e. food) with oxygen. When Earth formed roughly 4.6 billion years ago there was no oxygen in its atmosphere. Now, the concentration of oxygen is maintained near 21% by a delicate balance of biological, environmental and geological processes. Understanding the rise of O2, and the feedbacks that keep it stable, constitute one of the great puzzles of geobiology.

Oxygen supports all complex (multicellular) life on our planet. However,  there are good scientific reasons to believe there was no free O2 when the Earth formed about 4.6 billion years ago. This is because oxygen likes to form stable oxides with many other elements such as hydrogen, carbon, sulfur, and iron. An iron oxide you may be very familiar with is rust, and another common molecule that contains oxygen is water! Any free O2 in contact with these elements would react in a relatively short time and, therefore, disappear from the atmosphere, unless it was replenished. Evidence from sediments formed before 2.5 billion years ago supports this theory. They contain rounded grains of minerals like pyrite - an iron sulfide with the chemical formula FeS. You may know pyrite by its common name of fool's gold. Because their rounded shapes show that they must have become smooth during transport in flowing water, such as a river, they are known as ‘detrital’ minerals. These detrital grains are unstable in the presence of oxygen - the FeS molecule would quickly break down into an iron oxide and sulfate. So, our oxygen-intolerant mineral grains are rounded, showing that they were tossed around in a stream at the surface of the Earth, and thus, expose to the atmosphere. This good evidence for Earth’s early atmosphere having no free O2 - otherwise, these detrital minerals would never be preserved in the sedimentary rock record!

All this changed at about 2.4 billion years ago and, to the best of our knowledge, it happened very suddenly. Instead of detrital grains of unstable minerals geologists observe that most common sediments, such as sandstones, contain an abundance of sand grains coated with iron oxides (rust).   Their sudden appearance, and the knowledge that oxygen production during photosynthesis is a pivotal biological process, has led geologists and geobiologists to coin the term ‘Great Oxidation Event’ or GOE.  This event is also marked by the peak production of iron-bearing sediments known as the Banded Iron Formations (BIF).  These are literally mountains of iron oxides that are being mined for steel-making.

 The geochemical changes we see at the GOE could happen with just a small amount oxygen, perhaps as little as 0.01% of what we have today. It very likely took another 2 billion or so years to reach levels of 21% that support air-breathing animals. Exactly why atmospheric oxygenation took so long is not known but it is likely due to feedbacks in the way biology interacts with the atmosphere-ocean-rock system.  The time lag can be explained if iron and other reduced minerals in rocks acted as an oxygen ‘buffer’.  Such a lag would also have allowed early life to develop mechanisms to adapt to oxygen’s toxic effects and to develop metabolisms that make use of its incredible chemical properties. Still, understand how this all works is one of the great outstanding puzzles in the Earth sciences.

We know that free oxygen is a byproduct of the splitting of water during oxygenic photosynthesis.  This requires a sophisticated light-harvesting system that can capture high-energy photons in the spectrum of visible light. Today, this is not only found in green plants but in more primitive organisms such algae and cyanobacteria.  Paleontology and genetics tell us that the cyanobacteria are the most ancient group that is capable of oxygenic photosynthesis.

You would not be reading this article were it not for the remarkable properties of oxygen.  This is why understanding why we have an atmosphere with exactly the right amount to support intelligent beings is such a tantalizing problem.
http://www.jashow.org/wiki/index.php?title=The_Creation_Debate-Part_6

Geologists have followed this abiogenesis theory for a number of years. Initially, geologists were very optimistic that we would find buried in those lowest rock layers of (*Editor’s note: Several times it appears that the terms “biogenesis” and “abiogenesis” are used almost interchangeably. I have checked the videotape for this section and can state with certainty that the gentlemen are quoted correctly, which does not discount the possibility that they may have misspoken.)the earth—this bathtub ring, if you will, from this reducing atmosphere—this very much different atmosphere. And even as much as 20 years ago, geologists were claiming that those rocks really did prove the absence of oxygen in this very unusual condition.

Over the last 20 years though, geologists have more carefully studied those lower rock layers of the earth called the Precambrian strata and they have concluded generally that those oldest rocks are very rich in oxygen. For example, one of the oldest sedimentary rocks de­scribed and discovered by geologists on the earth has banded iron formation, and the major element in this rock is not iron, but is oxygen. And there are very many oxygen-rich rocks buried in the earth.

In fact, geologists have recently discovered sulfate deposits, sulfur and oxygen combined together and not sulfur combined with a metal such as lead or zinc. And geologists have discov­ered these oxidized iron deposits. Evidence of oxidation like soil development and many things are causing the evolutionists to question the whole reducing atmosphere scenario.

Carbon dioxide makes up less than one percent of the atmosphere. What good is such a small amount? Without it, plant life would die. That small amount is what plants need to take in, giving off oxygen in return. Humans and
animals breathe in the oxygen and exhale carbon dioxide. An increasing percentage of carbon dioxide in the atmosphere would tend to be harmful to humans and animals. A decreasing percentage could not support plant life. What a marvelous, precise, self-sustaining cycle has been arranged for plant, animal, and human life! 3  In addition to being a protective shell, the atmosphere keeps the warmth of the earth from being lost to the coldness of space. And the atmosphere is itself kept from escaping by the earth's gravitational pull. That gravity is just strong enough to accomplish this, but not so strong that our freedom of movement is hampered.

Assuming that the planetary atmosphere was not so reducing as to allow NH3 to be a major component of the atmosphere, the only known abiotic sources of fixed inorganic nitrogen would have included lightning, bolide impacts and possibly hydrothermal reactions in a reduced environment. At most, these reactions would have delivered approximately 1 Tmol yr−1; a flux that would have constrained CO2 fixation to less than 0.1% of modern values

Electrons, life and the evolution of Earth's oxygen cycle
2008 May 16
Assuming that the planetary atmosphere was not so reducing as to allow NH3 to be a major component of the atmosphere, the only known abiotic sources of fixed inorganic nitrogen would have included lightning, bolide impacts and possibly hydrothermal reactions in a reduced environment. At most, these reactions would have delivered a flux that would have constrained CO2 fixation to less than 0.1% of modern values. 5  That is, the initial reduction of Nitrogen Gas N2 to Ammonium NH4+ is at the expense of the oxidation of organic carbon to inorganic carbon, (  nitrogen fixation can be thought of as a type of respiratory pathway; however, unlike other respiratory pathways, it consumes rather than produces energy. )  while the oxidation of NH4+ to Nitrate  NO3− is coupled to the reduction of inorganic carbon to organic matter and the reduction of NO−3 to N2 is coupled to the oxidation of organic matter to inorganic carbon. All the three pathways are related to oxygen;

The destructive effect of oxygen, ultraviolet radiation from the sun and the short duration of an optimal atmosphere for their production, makes it unlikely that significant quantities of viable nucleotides and amino acids could ever accumulate in the primitive ocean. 6

1) http://www.ideacenter.org/contentmgr/showdetails.php/id/838
2. http://crossexamined.org/four-ways-the-earth-is-fine-tuned-for-life/
3) https://groups.google.com/forum/#!msg/talk.origins/6QlVBAGD_GY/00aLE8_XpC8J
4. http://www.sciencealert.com/volcanoes-shaped-life-on-earth
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2606772/
6. http://xwalk.ca/origin.html
7. http://nideffer.net/proj/Hawking/early_proto/orgel.html
8. http://sci-hub.ren/http://www.nrcresearchpress.com/doi/abs/10.1139/e76-119#.WpiFmh3waUk
9. https://www.nature.com/scitable/knowledge/library/earth-s-earliest-climate-24206248


Further reading:
http://www.scientificpsychic.com/etc/timeline/atmosphere-composition.html
http://en.wikipedia.org/wiki/Ozone-oxygen_cycle
http://www.universetoday.com/61080/oxygen-cycle/
http://www.ozonelayer.noaa.gov/science/basics.htm
http://science.howstuffworks.com/dictionary/physics-terms/ultraviolet-radiation-info.htm

A Big Problem for Naturalistic Explanations of Life's Origins: Zircon Shows Oxygen Present in the Early Earth
http://www.evolutionnews.org/2011/12/post_34053831.html



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2The earth's  atmosphere   Empty When did oxygen rise in the atmosphere ? Sun Mar 02, 2014 12:50 pm

Otangelo


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When did oxygen rise in the atmosphere ? 1

Debate has long reined over the mysterious origin of oxygen in our atmosphere. Because oxygen is such a key ingredient in life it would seem necessary for oxygen to be present before life could have formed.  However, the most accepted theory in scientific circles today is that life came first, then came oxygen. But isn’t oxygen needed for life? Here I will briefly introduce the dilemma of oxygen’s origins on earth and the conclusions (or lack there of) it provides. The story starts with earth. Earth is hungry to consume oxygen. Oxygen reacts with minerals in the earth, with hydrogen in the atmosphere, and dissolved minerals and gases in the ocean. The earth consumes oxygen relentlessly (Catling, 70). The oxygen absorbing substances are called “reductants,” and they are a problem for any source of oxygen (Catling, 69). David Catling, an Astrobiology Professor at the University of Washington writes, “While oxygen appears to be essential for complex life, planets are constructed with chemicals that consume oxygen, so oxygen should not accumulate. Earth’s oxygen rich atmosphere is rather mysterious,” (Catling, 69). In fact, the only way for oxygen to accumulate is for oxygen production to exceed earth’s ability to consume it. So what are the potential sources for oxygen? There are two sources for oxygen; biological and non-biological. The latter is a process called photodissociation, in which ultraviolet rays break apart water molecules separating the oxygen from the hydrogen. Studies have shown that the rate at which this could occur is the same rate at which hydrogen would escape the atmosphere (Des Marais). However, the rate at which this would occur is hardly sufficient to produce the amount of oxygen present on earth. (Des Marais). So the only other solution is biological. When organic carbon and pyrite become buried in sediments, mostly from the ocean, oxygen is released (Catling, 69). There is a problem with this theory though because it would require an increase of the burial rate to create the exponential increase needed for oxygen to overwhelm earth’s reductants, yet studies show that carbon burial in sedimentary rock was constant during this period of time in earth’s history (Siegel). So carbon burial cannot be the predominant cause.


The earth's  atmosphere   Oxygen-evolution-model


The standard uniformitarian model for the evolution of life and chemical compositions in earth’s atmosphere.

However, organic life itself creates oxygen. Cyanobacteria was the first photosynthesizer, and thus the first producer of oxygen (Eden, 33 and Wolfe, 143). Cyanobacteria itself cannot be the cause for the accumulation though because according to current theories and history models cyanobacteria appeared almost a billion years before the oxygen accumulated in earth’s atmosphere. So again, we hit a brick wall. In the end there are a variety of theories explaining the oxygen build up, but there is a reoccurring theme in all of them: Life came before oxygen, because life is the cause of oxygen. As science writer David Biello writes, “Climate, volcanism, plate tectonics all played a key role in regulating the oxygen level during various time periods. Yet no one has come up with a rock-solid test to determine the precise oxygen content of the atmosphere at any given time from the geologic record. But one thing is clear—the origins of oxygen in Earth’s atmosphere derive from one thing: life,” (Biello). This “fact” that oxygen origins come from life is assumed, yet when analyzed, presents a problem that jeopardizes the entire theory of oxygen’s origin.


The earth's  atmosphere   Cyanobacteria

Cyanobacteria. The assumed origin of oxygen on earth.

Oxygen and life have a catch 22 relationship. Oxygen is very harmful to life (Eden, 33). At the same time oxygen is needed to provide the ozone layer which protects life from ultraviolet radiation (UVR)coming from the sun (Perlman & Milder, pp. 121). If Cynobateria came before oxygen, because it is the cause of oxygen, then Cynobacteria would have had to develop several forms of protection to mitigate the damage from UVR: avoidance, scavenging, screening, repair, and programmed cell death (Singh, Hader, and Sinha). However, UVR damage is immediate and the time needed to “evolve” protection against it via natural selection, incredibly slow. So, UVR damage would occur before any such defense mechanisms could evolve. One seemingly good solution to this problem is water. More specifically, the ocean. If cyanobacteria first evolved in the ocean, the ocean would protect them from UVR, right? Well not exactly. The only way for the ocean to block UVR is if you go deep underwater. At which point the depth is too deep to photosynthesize. The argument then follows, that perhaps life first originated in the ocean, then overtime evolved enough to come up to the surface to photosynthesize without getting burned by UVR.  But even this theory has its own problems. Namely the problem of hydrolosis or “water-splitting.” The US National Academy of Sciences explains, “In water, the assembly of nucleosides from component sugars and nucleobases, the assembly of nucleotides from nucleosides and phosphate, and the assembly of oligonucleotides from nucleotides are all thermodynamically uphill in water. Two amino acids do not spontaneously join in water. Rather, the opposite reaction is thermodynamically favored at any plausible concentrations: polypeptide chains spontaneously hydrolyze in water, yielding their constituent amino acids,” (Luskin). Physicist Richard Morris concurs, “… water tends to break chains of amino acids. If any proteins had formed in the ocean 3.5 billion years ago, they would have quickly disintegrated,” (Morris, 167). Additionally, the cytoplasm of living cells contain essential minerals of potassium, zinc, manganese and phosphate ions. If cells manifested naturally, these minerals would need to be present nearby. But marine environments do not have widespread concentrations of these minerals (Switek). Thus, it is clear, life could not have formed in the ocean. What we’re left with is a perplexing paradox: Water prevents the formation of life. Oxygen prevents the formation of life. Lack of oxygen prevents the formation of life. Yet the only source of oxygen currently accepted is organic. How can organics be the source of something it requires present in the first place? The only way for life to create oxygen is if the life itself already has built in mechanisms present from the very beginning to protect itself from the outside environment. Needless to say, the specific details regarding the origin of oxygen remain mysterious.

The stability of the RNA bases: Implications for the origin of life

http://www.pnas.org/content/95/14/7933.full

High-temperature origin-of-life theories require that the components of the first genetic material are stable. We therefore have measured the half-lives for the decomposition of the nucleobases. They have been found to be short on the geologic time scale. At 100°C, the growth temperatures of the hyperthermophiles, the half-lives are too short to allow for the adequate accumulation of these compounds (t1/2 for A and G ≈ 1 yr; U = 12 yr; C = 19 days). Therefore, unless the origin of life took place extremely rapidly (<100 yr), we conclude that a high-temperature origin of life may be possible, but it cannot involve adenine, uracil, guanine, or cytosine. The rates of hydrolysis at 100°C also suggest that an ocean-boiling asteroid impact would reset the prebiotic clock, requiring prebiotic synthetic processes to begin again. At 0°C, A, U, G, and T appear to be sufficiently stable (t1/2 ≥ 106 yr) to be involved in a low-temperature origin of life. However, the lack of stability of cytosine at 0°C (t1/2 = 17,000 yr) raises the possibility that the GC base pair may not have been used in the first genetic material unless life arose quickly (<106 yr) after a sterilization event. A two-letter code or an alternative base pair may have been used instead.

http://reasonandscience.heavenforum.org/t1404-the-genetic-code-is-nearly-optimal-for-allowing-additional-information-within-protein-coding-sequences#2011

some scientists suggest that the genetic code found in nature emerged from a simpler code that employed codons consisting of one or two nucleotides. Over time, these simpler genetic codes expanded to eventually yield the universal genetic code based on coding triplets. The number of possible genetic codes based on one or two nucleotide codons is far fewer than for codes based on coding triplets. This scenario makes code evolution much more likely from a naturalistic standpoint. One complicating factor for these proposals arises, however, from the fact that simpler genetic codes cannot specify twenty different amino acids. Rather, they are limited to sixteen at most. Such a scenario would mean that the first lifeforms had to make use of proteins that consisted of no more than sixteen different amino acids. Interestingly, some proteins found in nature, such as ferredoxins, are produced with only thirteen amino acids. On the surface, this observation seems to square with the idea that the genetic code found in nature arose from a simpler code. Yet, proteins like the ferredoxins are atypical. Most proteins require all twenty amino acids. This requirement, coupled with recent recognition that life in its most minimal form needs several hundred proteins , makes these types of models for code evolution speculative at best. The optimal nature of the genetic code and the difficulty accounting for the code's origin from an evolutionary perspective work together to support the conclusion that an Intelligent Designer programmed the genetic code, and hence, life.

Catling writes, “Although we think we know when oxygen first appeared and rose, we know very little about its rise to the present level, especially about the relationship between atmospheric oxygen and the development of animals,” (Siegel). 
As time goes on maybe these issues will be clarified. But the paradox between life and oxygen remains. So much so that it leaves me to postulate the more likely scenario of life being created with infrastructure necessary to survive in its environment. That is, God created an environment for life, and life for an environment. There are just too many problems with a step by step natural origin for all the factors required for the origin of oxygen. As of right now, at least, it is the only answer to this paradox.


Biello, D., (August 2009) “The Origin of Oxygen in Earth’s Atmosphere,”  http://www.scientificamerican.com/article/origin-of-oxygen-in-atmosphere/
Catling, D., (2008) “Where did the oxygen in the atmosphere come from?” as written in Seventy Mysteries of the Natural World, ed. M.J. Benton, (London: Thames and Hudson) http://faculty.washington.edu/dcatling/Catling2008-O2-origin.pdf
Des Marais, D.J. (Oct 1999) “Where did the Earth’s atmospheric oxygen come from?” scientificamerican.com
Luskin, C., (Feb 2012) “More Scientists Admit the Mystery of Life’s Origin,” www.evolutionnews.org
Morris, R., (2002) The Big Questions, (Times Books/Henry Holt:New York,NY)
Out of Eden, (2005) (London: Transworld Publishers)
Perlman, D.L. & Milder, J.C. (2004) Practical Ecology for Planners, Developers and Citizens, (Washington, DC: Island Press)
Siegel, L., (July 2003) “The Rise of Oxygen,” Astrobiology Magazine, http://www.astrobio.net
Singh, S.P., Hader, D.P., & Sinha, R.P. (April, 2010) “Cyanobacteria and ultraviolet radiation (UVR) stress: Mitigation Strategies,” as accessed on Feb 18, 2013 at http://www.ncbi.nlm.nih.gov/pubmed/19524071
Switek, B., (February 2012) “Debate Bubbles Over the Origin of Life,” http://www.nature.com
Wolfe, N., (Jan 2013) “Small Small World,” National Geographic

1) https://matthew2262.wordpress.com/2013/03/20/in-the-beginning-was-oxygen/



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Did the Early Earth Have a Reducing Atmosphere?

After reviewing evolutionists' speculations on the origin of life, Clemmey and Badham say, "... the dogma has arisen that Earth's early atmosphere was anoxic,..."1 By "anoxic" they mean an atmosphere without free oxygen gas (O2), very different from the oxidizing mixture we breathe. The generally accepted model for the evolution of the atmosphere2 supposes that before about 1.9 billion years ago the earth's atmosphere was a reducing mixture of nitrogen (N2), methane (CH4), water vapor (H2O), and possibly ammonia (NH3). Solar radiation and lightning discharges into the reducing gas mixture are believed by the consensus of evolutionists to have produced natural organic compounds and eventually life itself. The reason evolutionists postulate an anoxic and reducing atmosphere is mentioned by Miller and Orgel, "We believe that there must have been a period when the earth's atmosphere was reducing, because the synthesis of compounds of biological interest takes place only under reducing conditions."3

If the dogma of the Precambrian reducing atmosphere is true, we would expect to find geologic evidence in the Archean and lower Proterozoic strata (believed by evolutionists to be older than 1.9 billion years). Although altered by diagenesis and metamorphism, the oldest sedimentary rocks should possess distinctive chemical composition and unusual mineral assemblages.

PLACERS OF UNSTABLE METALLIC MINERALS

Pebble and sand placer deposits of upper Archean and lower Proterozoic age occur in southern Canada, South Africa, southern India and Brazil. Some of these are known to be cemented by a matrix containing mineral grains of pyrite (FeS2) and uraninite (UO2). Pyrite has the reduced state of iron (without oxygen, but with sulfur) which is unstable as sedimentary grains in the presence of oxygen. Uraninite has the partly oxidized state of uranium which is oxidized to UO3 in the presence of the modern atmosphere. These unstable mineral grains in gravel and sand concentrates have been claimed by some geologists to indicate a reducing atmosphere at the time of deposition.

Although ancient placers of unstable metallic minerals occur in various places, these are by no means the only types of heavy mineral concentrates known from Archean and lower Proterozoic strata. Davidson4 studied heavy mineral concentrates of completely modern aspect in strata nearly contemporaneous with the unstable concentrates. If deposition occurred under a reducing atmosphere all sediments would be expected to contain pyrite. The normally oxidized concentrates could be better used to argue for oxidizing atmosphere with the unstable assemblages being accumulated under locally reducing conditions.

Clemmey and Badham5 are bold enough to propose that the unstable minerals were disaggregated by mechanical weathering, with limited chemical and biological weathering, under an oxidizing atmosphere. Support comes from Zeschke6 who has shown that uraninite is transported by the oxidizing water of the modern Indus River in Pakistan. Grandstaff7 has shown that the ancient uraninite placers contain the form of thorium-rich uraninite which is most stable under modern oxidizing conditions. Pyrite has also been reported in modern alluvial sediments, especially in cold climates.8 It is noteworthy that magnetite, an oxide of iron unstable in modern atmospheric conditions, is the most common mineral constituent of the black sand concentrates on modern beaches. Evidently, brief exposures to special oxidizing conditions are not sufficient to oxidize many unstable minerals. Thus, these metallic mineral placers do not require a reducing atmosphere.

IRON DEPOSITS

Another frequently cited evidence for an early reducing atmosphere comes from ancient iron ore deposits called "banded iron formations." These are common in Archean and Proterozoic strata, the best known being the ores of the Lake Superior region. The iron deposits consist typically of thin laminae of finely crystalline silica alternating with thin laminae of iron minerals. Magnetite (Fe3O4), an incompletely oxidized iron mineral, and hematite (Fe2O3), a completely oxidized iron mineral, are common in the banded iron formations. Magnetite may be considered a mixture of equal parts of FeO (iron in the less oxidized, ferrous state) and Fe2O3 (iron in the oxidized, ferric state). Because magnetite would be more stable in an atmosphere with lower oxygen pressure, some evolutionists have argued that banded iron accumulated during the transition from a reducing to a fully oxidizing atmosphere some 1.9 billion years ago. Soluble ferrous iron abundant in the early reducing sea, they suppose, was precipitated as oxygen produced the insoluble, ferric iron of the modern oxidizing sea.

Three problems confront the transition hypothesis. First, the banded iron is not direct evidence of a reducing atmosphere; it only suggests that an earlier reducing atmosphere may have existed. Other options are certainly possible. The iron formations contain oxidized iron and would require an oxidizing atmosphere or other abundant source of oxygen!

A second problem is that the iron formations do not record a simultaneous, worldwide precipitation event, but are known to occur in older strata when the atmosphere was supposed to be reducing and in younger strata when the atmosphere was undoubtedly oxidizing. Dimroth and Kimberley9 compare Archean iron formations (believed to have been deposited at the same time as unstable metallic mineral placers more than 2.3 billion years ago) with Paleozoic iron formations (believed to have been deposited in an oxidizing atmosphere less than 0.6 billion years ago). The similarities can be used to argue that the Archean atmosphere was oxidizing.

A third problem is that red, sandy, sedimentary rocks called "red beds" are found in association with banded iron formations. The red color in the rock is imparted by the fully oxidized iron mineral hematite, and the rocks are characteristically deficient in unoxidized or partly oxidized iron minerals (e.g., pyrite and magnetite). Red beds are known to occur below one of the world's largest Proterozoic iron formations and have been reported in Archean and lower Proterozoic rocks.10 By their association with iron formations, red beds also indicate oxidizing conditions.

SULFATE DEPOSITS

When sulfur combines with metals under reducing conditions the result is sulfide minerals such as pyrite (FeS2), galena (PbS), and sphalerite (ZnS). When sulfur combines with metals under oxidizing conditions the result is sulfate minerals such as barite (BaSO4), celestite (SrSO4), anhydrite (CaSO4), and gypsum (CaSO42H2O). If the earth had a reducing atmosphere, we might expect extensive stratified, sulfide precipitates in Archean sedimentary rocks. These would not have formed by volcanic-exhalative processes (as some sulfide minerals do even today), but directly from sea water (impossible in our modern oxidizing ocean). No deposits of this type have been found. Instead, Archean bedded sulfate has been reported from western Australia, South Africa, and southern India.11 Barite appears to have replaced gypsum which was the original mineral deposited as a chemical precipitate. This provides evidence of ancient oxidizing surface conditions and oxidizing ground water. The extent of the oxidizing sulfate environment and its relation to ancient atmospheric composition are speculation, but, again we see evidence of Archean oxygen.

OXIDIZED WEATHERING CRUSTS

When a rock fragment is deposited, its surface is in contact with the external environment and can be altered chemically. Thus, pebbles and lava flows in the modern atmosphere weather to form oxide minerals at their surfaces. Even in the ocean this weathering occurs. In a similar fashion, Dimroth and Kimberley12 report oxidative weathering of pebbles occurring below a banded iron formation and describe hematite weathering crusts on Archean pillow basalt (believed to represent a submarine lava flow). Again, Archean oxygen is indicated.

CONCLUSION


Much more could be written concerning the ancient atmosphere. Water-concentrated, unstable metallic minerals are not diagnostic of reducing conditions. The many mineral forms of ferrous and ferric iron in Archean and lower Proterozoic rocks are most suggestive of oxygen-rich conditions. Sulfate in the oldest rocks indicates oxygen in the water. Weathered crusts on ancient rocks appear to require oxygen in both air and water. To the question, "Did the early earth have a reducing atmosphere?" we can say that reducing evidence has not been documented in the rocks. An evolutionist can maintain that a reducing atmosphere existed before any rocks available for study formed, but such a belief is simply a matter of faith. The statement of Walker is true, "The strongest evidence is provided by conditions for the origin of life. A reducing atmosphere is required."13 The proof of evolution rests squarely on the assumption of evolution!
Origin of life: Time to end speculation about a reducing atmosphere for the early Earth

It is universally claimed that the early Earth had a reducing atmosphere. Models have been proposed for the gases to have accumulated after outgassing of volatiles from volcanism. This reducing atmosphere was originally thought to have been dominant throughout the Precambrian, but signs of oxygenation have pushed it back earlier than the earliest rocks that researchers have discovered. The earlier claims for a reducing atmosphere have other explanations, such as resulting from the action of hydrodynamic fluids. This has put severe constraints on theories of abiogenesis, because the proposed mechanisms typically presuppose a reducing atmosphere. By the earliest Archaean, the atmosphere was at least neutral – so abiogenesis is inferred to have occurred even earlier. But moving back earlier brings us to the Late Heavy Bombardment which is generally deemed to have obliterated all traces of any life that may have been present. So there is a little window in the Hadean that is deemed to have offered a reducing atmosphere free from the destructive bombardment.

   The evidence for a Hadean reducing atmosphere has been entirely theoretical. It does not rest on empirical evidence because there has been so little to work with. However, a new study of zircon crystals has reported some fascinating results that allow speculation about the Hadean black box to be replaced by empirical evidence.

Origin of life: Time to end speculation about a reducing atmosphere for the early Earth

https://reasonandscience.catsboard.com/t1556-when-did-oxygen-rise-in-the-atmosphere?highlight=atmosphere

Zircons have been identified that carry signatures identifying them with the Hadean – and zircons are remarkably stable once formed. Using zircons dated to almost 4.4 Ga, the researchers have analysed their redox state (a measure of the degree of oxygenation of the mineral). This gives a handle on the type of gases that would have been outgassed by the magmas, and so, according to these models of Earth history, the type of atmosphere that would have been formed.

   It is important to realise what was predicted by prevailing theories: the redox state of the magmas with which the zircons were associated was expected to be strongly reducing. This prediction is a necessary part of the Earth having a reducing atmosphere in the Hadean. The research findings did not confirm the prediction
.
Harry Clemmey and Nick Badham, “Oxygen in the Precambrian Atmosphere: An Evaluation of the Geological Evidence,” Geology, 10, no. 3, (March 1982): 141.

It is suggested that from the time of the earliest dated rocks at 3.7 (billion years) ago, Earth had an oxygenic atmosphere.

Charles Thaxton, Walter Bradley, and Roger Olsen, The Mystery of Life’s Origin (Dallas: Lewis and Stanley, 1992), 80.
The only trend in recent literature is the suggestion of far more oxygen in the early atmosphere than anyone imagined. Commonwealth Scientific and Industrial Research finds that “Primordial Air May Have Been Breathable,” SpaceDaily, January 11, 2002 (http://www.spacedaily.com/news/early-earth-02a.html). Primordial Air may have been “breathable.” The Earth may have had an oxygen-rich atmosphere as long ago as three billion years and possibly even earlier, three leading geologists claimed.

It is only possible to maintain a high oxygen concentration in the face of these continual depredations if it is also continually produced. The main process responsible for producing O2 in these large quantities is photosynthesis. Whereas we, like animals, breathe in oxygen and exhale carbon dioxide, plants do the opposite. Trees, grasses, algae, and other plants all harvest sunlight to make carbohydrates, and in so doing they take in carbon dioxide and release oxygen as a waste product. Although plants themselves use up some of their own carbohydrates to power their metabolisms, the total amount of photosynthesis (oxygen production) on Earth slightly exceeds the total amount of respiration (oxygen consumption), leading to an ongoing net injection of oxygen into Earth’s atmosphere. This source of oxygen is sufficient to match the sinks due to weathering of newly exposed rocks and chemical alterations of newly emitted volcanic gases. In this way the atmosphere is kept rich in oxygen. 1

Oxygen is continually lost from the atmosphere in order to “oxidize” (rust) iron  and other minerals in newly exposed rocks. It readily combines with many of the gases and minerals ejected from volcanoes, leading to a loss of free oxygen into the newly formed molecules. It reacts with volcanic hydrogen (H2) to form water (H2O) via the reaction 2H2 + O2 → 2H2O, with volcanic hydrogen sulfide (H2S) and sulfur dioxide (SO2) to form sulfate (SO4), and with carbon monoxide (CO) to form carbon dioxide (CO2) via the reaction 2CO + O2 → 2CO2. Oxygen is used up following every entry of methane (CH4) into the atmosphere, to convert it into carbon dioxide (CO2). the great amounts of oxygen in the atmosphere in the face of large ongoing losses can only be understood if the oxygen is continually replenished by some large-scale process. That process is photosynthesis. Now I will consider how exactly oxygen first appeared in the atmosphere and ocean, and the changes this wrought on the living environment. The first life on Earth was presumably chemolithotrophic.  That is to say, it must have obtained its energy from conducting chemical reactions between inorganic rather than organic chemical substrates. It is likely that such chemolithotrophs proliferated rapidly until all the profitable chemicals in the environment were completely used up. Then, early in Earth history, microbes acquired the ability to capture sunlight energy followed by the ability to store the captured energy within biological molecules (for example, sugars) that they could keep for later use. Suddenly they had access to an inexhaustible energy supply. This was a change of great significance. When you look at a grain of sugar you can think of it as a piece of distilled sunlight energy in solid form—captured by a sugar cane plant. This crucial advance (taking energy directly from the sun) opened up a whole new means of subsistence. The very first forms of photosynthesis may not have evolved oxygen. 

Still today, in hot springs around the world, purple and green sulfur bacteria use hydrogen sulfide (H2S) and hydrogen (H2) as electron donors during photosynthesis and do not release oxygen as a by-product.

Some phototrophic and aerobic sulfur bacteria are capable of using electrons from oxidation of sulfide to support chemolithotrophic growth. 2 For the most part, biosulfur reduction or oxidation requires unique enzymatic activities with metal cofactors participating in electron transfer. That rises the question about how these mechanisms emerged on an early earth. If the naturalistic narrative were true, we would and should ask: why did oxygenic photosynthesis evolve, if supply of hydrogen sulfide (H2S) and hydrogen (H2) as electron donors were never of short supply in early earth ?

In a surprising discovery, some of these non-oxygen-producing photosynthesizers even thrive on arsenic,  and in fact depend on it for their existence. However, evolutionary experimentation soon hit upon the fundamental chemical reaction ( the just so assertion and story-telling  is noted ) :

CO2 + H2O sunlight CH2O +O2

as the most successful means of converting sunlight energy to chemical energy. From this point on, as long as life didn’t die out, the Earth was probably destined to eventually acquire an oxygen-rich atmosphere. Over time, as oxygen continued to be pumped out by the newly arrived photosynthesizers, all of the reduced substances on Earth (in the air, on land, and in the sea) became oxidized, after which oxygen was then free to build up in the atmosphere and ocean.

1. On Gaia A Critical Investigation of the Relationship between Life and Earth Toby Tyrrell, page 118
2. https://link.springer.com/chapter/10.1007%2F978-94-017-9269-1_10



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4The earth's  atmosphere   Empty Re: The earth's atmosphere Sun Mar 02, 2014 4:32 pm

Otangelo


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Reducing environment fiasco 1
The idea of the primitive reducing atmosphere has been severely challenged by the available data from geology, geophysics and geochemistry.[28],[29] There is no geologic evidence for either a reducing primitive atmosphere or an early earth containing large amounts of methane gas. Moreover, a quick disappearance of ammonia may take place, because the effective threshold for degradation by ultraviolet radiation is 2,250Å.[30] Also, a quantity of ammonia equivalent to the present atmospheric nitrogen would be destroyed in approximately 30,000 years.[31] Experiments confirm that irradiating a highly reducing atmosphere produces hydrophobic organic molecules that are absorbed by sedimentary clays. This indicates that the earliest rocks should have contained an extraordinarily large amount of carbon or organic chemicals. However, this is not supported by the observed data. Based on observations from the stratigraphical record, Davidson explained that there is no evidence that a primeval reducing atmosphere might have persisted during much of Precambrian time.[32] Theoretical calculation also confirms that dissociation of water vapor by ultraviolet light must have produced enough oxygen very early in the history of the earth to create an oxidizing atmosphere.[33]

Now for many decades it is well known that the primordial environment was most likely not composed of methane or ammonia, and thus would not have been favorable to Miller-Urey type chemistry. David Deamer, an origin of life theorist says, “This optimistic picture began to change in the late 1970s, when it became increasingly clear that the early atmosphere was probably volcanic in origin and composition, composed largely of carbon dioxide and nitrogen rather than the mixture of reducing gases assumed by the Miller-Urey model. Carbon dioxide does not support the rich array of synthetic pathways leading to possible monomers...”[34] Jeffrey Bada and his co-researchers also echoed the similar statement: “Geoscientists today doubt that the primitive atmosphere had the highly reducing composition Miller used...”[35] Interestingly, it is reported in Earth and Planetary Science Letters that chemical properties have been effectively unvarying over earth’s history, and thus concludes that “Life may have found its origins in other environments or by other mechanisms.”[36] In 1996 Miller himself stated, “We really don’t know what the Earth was like three or four billion years ago. So there are all sorts of theories and speculations. The major uncertainty concerns what the atmosphere was like. This is a major area of dispute.”[37] Many prominent scientists in recent time have discarded the Miller-Urey experiment and the ‘primordial soup’ hypothesis it claimed to support. In 1990 the Space Studies Board of the National Research Council suggested that origin of life scientists should undertake a “reexamination of biological monomer synthesis under primitive Earthlike environments, as revealed in current models of the early Earth.”[38] In a review, Leslie Orgel has expressed that, “The relevance of all of this early work to the origin of life has been questioned because it now seems very unlikely that the Earth’s atmosphere was ever as strongly reducing as Miller and Urey assumed.”[39] In a recent NPR report biochemist Nick Lane states that the primordial soup theory is now expired.[40]
However, this does not lead to an end to speculation on the chemical origin of life. Many new hypothetical primitive atmospheres have been proposed.[41]-[44] It is also speculated that organic compounds required for the origin of life may have come from outer space, for instance interplanetary dust particles, comets, asteroids and meteorites.[45] However, the major question will be: was extraterrestrial organic material ever efficiently delivered intact to the Earth?[46] Scientists may continually arrive at many such alternative theories about the unknown past. However, updated science textbooks should at least inform new generations about this now-outmoded recipe of ‘primordial soup’.
When did oxygenic photosynthesis evolve?

The atmosphere has apparently been oxygenated since the ‘Great Oxidation Event’ ca 2.4 Ga ago, but when the photosynthetic oxygen production began is debatable. However, geological and geochemical evidence from older sedimentary rocks indicates that oxygenic photosynthesis evolved well before this oxygenation event. Fluid-inclusion oils in ca 2.45 Ga sandstones contain hydrocarbon biomarkers evidently sourced from similarly ancient kerogen, preserved without subsequent contamination, and derived from organisms producing and requiring molecular oxygen. Mo and Re abundances and sulphur isotope systematics of slightly older (2.5 Ga) kerogenous shales record a transient pulse of atmospheric oxygen. As early as ca 2.7 Ga, stromatolites and biomarkers from evaporative lake sediments deficient in exogenous reducing power strongly imply that oxygen-producing cyanobacteria had already evolved.

http://rstb.royalsocietypublishing.org/content/363/1504/2731.long

Even at ca 3.2 Ga, thick and widespread kerogenous shales are consistent with aerobic photoautrophic marine plankton, and U–Pb data from ca 3.8 Ga metasediments suggest that this metabolism could have arisen by the start of the geological record. Hence, the hypothesis that oxygenic photosynthesis evolved well before the atmosphere became permanently oxygenated seems well supported.

We can now say with some certainty that many scientists studying the origins of life on Earth simply picked the wrong atmosphereWe can now say with some certainty that many scientists studying the origins of life on Earth simply picked the wrong atmosphere 2 During this process they looked for concentrations of a rare Earth metal called cerium in the zircons. Cerium is an important oxidation gauge because it can be found in two oxidation states, with one more oxidized than the other. The higher the concentrations of the more oxidized type cerium in zircon, the more oxidized the atmosphere likely was after their formation.

The calibrations reveal an atmosphere with an oxidation state closer to present-day conditions. The findings provide an important starting point for future research on the origins of life on Earth. The scientists sought to determine the oxidation levels of the magmas that formed these ancient zircons to quantify, for the first time ever, how oxidized were the gases being released early in Earth’s history. Understanding the level of oxidation could spell the difference between nasty swamp gas and the mixture of water vapor and carbon dioxide we are currently so accustomed to, according to study lead author Dustin Trail, a postdoctoral researcher in the Center for Astrobiology.

“By determining the oxidation state of the magmas that created zircon, we could then determine the types of gases that would eventually make their way into the atmosphere,” said Trail.

To do this Trail, Watson, and their colleague, postdoctoral researcher Nicholas Tailby, recreated the formation of zircons in the laboratory at different oxidation levels. They literally created lava in the lab. This procedure led to the creation of an oxidation gauge that could then be compared with the natural zircons.

The scientists sought to determine the oxidation levels of the magmas that formed these ancient zircons to quantify, for the first time ever, how oxidized were the gases being released early in Earth’s history. Understanding the level of oxidation could spell the difference between nasty swamp gas and the mixture of water vapor and carbon dioxide we are currently so accustomed to, according to study lead author Dustin Trail, a postdoctoral researcher in the Center for Astrobiology. “By determining the oxidation state of the magmas that created zircon, we could then determine the types of gases that would eventually make their way into the atmosphere,” said Trail. To do this Trail, Watson, and their colleague, postdoctoral researcher Nicholas Tailby, recreated the formation of zircons in the laboratory at different oxidation levels. They literally created lava in the lab. This procedure led to the creation of an oxidation gauge that could then be compared with the natural zircons.

During this process they looked for concentrations of a rare Earth metal called cerium in the zircons. Cerium is an important oxidation gauge because it can be found in two oxidation states, with one more oxidized than the other. The higher the concentrations of the more oxidized type cerium in zircon, the more oxidized the atmosphere likely was after their formation. The calibrations reveal an atmosphere with an oxidation state closer to present-day conditions. The findings provide an important starting point for future research on the origins of life on Earth.

1. http://scienceandscientist.org/biology/#_ftnrefDNA
2. https://news.rpi.edu/luwakkey/2953



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5The earth's  atmosphere   Empty The Mystery of Earth’s Oxygen Wed Apr 02, 2014 1:51 pm

Otangelo


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The Mystery of Earth’s Oxygen

To Donald E. Canfield, there’s something astonishing in every breath we take. “People take oxygen for granted because it’s just there and we breathe it all the time,” said Dr. Canfield, a geochemist at the University of Southern Denmark. “But we have the only planet we know of anywhere that has oxygen on it.”

A mat of blue-green algae in China. Cyanobacteria like this were some of the first organisms on Earth to produce oxygen as a waste product of photosynthesis.

What’s even more astonishing is that the earth started out with an oxygen-free atmosphere. It took billions of years before there was enough of it to keep animals like us alive.

Although scientists have been struggling for decades to reconstruct the rise of oxygen, they’re still making fundamental discoveries. In just the past two weeks, for example, Dr. Canfield and his colleagues have published a pair of studies that provide significant clues about some of the most important chapters in oxygen’s history. They’re finding that our weirdly oxygen-rich atmosphere is the result of a complicated dance of geology and biology.

To study the ancient atmosphere, geochemists examine the chemical fingerprints left behind on rocks. Some rocks contain molecules that could have formed only in the presence of oxygen. The more of those molecules geochemists find in a rock, the more oxygen must have been in the atmosphere at the time.

When they look at the oldest rocks on earth, they find no trace of oxygen in the atmosphere. Instead, their research indicates that earth’s primordial air was made up mostly of carbon dioxide, methane and nitrogen. The sun’s rays created some free oxygen by splitting it off from carbon dioxide and other molecules. But the oxygen disappeared almost as soon as it was formed.

That’s because oxygen is an enormously friendly element, forming bonds with a wide range of molecules. It attached to the iron in rocks, for example, creating rust. It joined with hydrogen spewed out from volcanoes to form hydrogen peroxide and other compounds. Our planet, in other words, was a giant oxygen vacuum in its early years.

That changed about three billion years ago. In the Sept. 26 issue of Nature, Dr. Canfield and his colleagues reported the fingerprints of oxygen in rocks from that time period. They estimate that the atmosphere three billion years ago had only 0.03 percent of today’s oxygen levels. That may not sound like much, but it marked a huge shift in the earth’s chemistry.

Sunlight alone couldn’t have put that much oxygen in the atmosphere. Only life could.

By three billion years ago, some microbes had evolved the ability to carry out photosynthesis. Floating at the surface of the ocean, they used energy from sunlight to grow on carbon dioxide and water. They gave off oxygen as waste.

Much of the oxygen released by these photosynthetic microbes was sucked out of the atmosphere by the earth’s vacuum. When microbes died, oxygen reacted with their carbon.

But a tiny amount of oxygen remained behind because some of the organic matter from the dead microbes sank from the surface of the ocean to the sea floor, where oxygen couldn’t react with it. The oxygen remained in the air.

Oxygen remained fairly scarce for the next few hundred million years. But during that time, the earth’s vacuum was getting weak. The planet was cooling, and so its volcanoes spewed less hydrogen into the atmosphere to suck up oxygen.

In his forthcoming book, “Oxygen: A Four Billion Year History,” Dr. Canfield suggests that this weak vacuum drove a sudden climb in oxygen that geochemists see in rocks from about 2.3 billion years ago. “Now we get to the point where the earth has calmed down enough that the balance has tipped in the favor of oxygen,” he said.

This oxygen boom may have added fuel to life’s fire. The extra oxygen in the atmosphere attacked rocks exposed on land, freeing up phosphorus and iron to flow into the ocean to act as fertilizer. The microbes bloomed even more, sending up even more oxygen.

Reporting last week in The Proceedings of the National Academies of Sciences, Dr. Canfield and his colleagues report that there was so much oxygen in the atmosphere that it penetrated down a thousand feet into the ocean. Dr. Canfield speculates that oxygen may have become as abundant as it is today, at least for a while.

But this boom created its own bust. Microbes rained down onto the sea floor, creating carbon-rich rocks. Later, the rocks were lifted up to form dry land, where they could react with the oxygen, pulling it out of the atmosphere.

Life itself, in other words, turned earth’s vacuum back up again. By 2 billion years ago, oxygen levels were down to about 0.01 percent of current levels.

Life and earth have continued to twiddle the oxygen knob over the past two billion years. When plants evolved, for example, they began storing huge amounts of carbon in wood and other tough tissues, leaving less to react with oxygen and pull it out of the atmosphere. By 300 million years ago, oxygen had risen to levels as high as 50 percent higher than today.

But as continents moved across the globe, the planet’s geography came to favor deserts. Forests shrank, bringing down the oxygen levels.

As Dr. Canfield gets better acquainted with the tumultuous history, he gets less certain about its future. Will the earth hold on to its remarkable supply of oxygen, or will it run low again? “I’m not sure we have a good prediction,” Dr. Canfield said. “That depends a lot on the vagaries of geography.”

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6The earth's  atmosphere   Empty Re: The earth's atmosphere Fri Jan 09, 2015 8:01 pm

Otangelo


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http://www.truenews.org/Creation_vs_Evolution/origin_of_life.html

Another Atmosphere

The atmospheric conditions proposed by Oparin, Haldane and Urey were radically different from what exists today. Because oxygen destroys the chemical building blocks of life, they speculated that the early earth had an oxygen-free atmosphere. However, in the last few decades, evidence has surfaced that has convinced most atmospheric scientists that the early atmosphere contained abundant oxygen.

In the 1970’s Apollo 16 astronauts discovered that water is broken down into oxygen and hydrogen gas in the upper atmosphere when it is bombarded by ultraviolet radiation. This process, called photo dissociation, is an efficient process which would have resulted in the production of large quantities of oxygen in a relatively short time. Studies by the astronauts revealed that this process is probably a major source of oxygen in our current atmosphere.

The assumption of an oxygen-free atmosphere has also been rejected on theoretical grounds. The ozone layer around planet earth consists of a thin but critical blanket of oxygen gas in the upper atmosphere. This layer of oxygen gas blocks deadly levels of ultraviolet radiation from the sun. Without oxygen in the early atmosphere, there could have been no ozone layer over the early earth. Without an ozone layer, all life on the surface of planet earth would face certain death from exposure to intense ultraviolet radiation. Furthermore, the chemical building blocks of proteins, RNA and DNA, would be quickly annihilated because ultraviolet radiation destroys their chemical bonds. It doesn’t matter if these newly formed building blocks are in the atmosphere, on dry ground, or under water.

So evolutionists have a major dilemma. The chemical building blocks of life would be destroyed if oxygen was present, and they would be destroyed if it wasn’t! This "catch 22" has been noted by evolutionist and molecular biologist Michael Denton: "What we have then is a sort of ‘Catch 22’ situation. If we have oxygen we have no organic compounds, but if we don’t we have none either." Even if the building blocks of life could survive the effects of intense ultraviolet radiation and form life spontaneously, the survival of any subsequent life forms would be impossible in the presence of such heavy ultraviolet light. Ozone must be present to protect any surface life from the deadly effects of ultraviolet radiation from the sun.

Finally, the assumption that there was no oxygen in the early atmosphere is not borne out by the geologic evidence. Geologists have discovered evidence of abundant oxygen content in the oldest known rocks on earth. Again, Michael Denton: "Ominously, for believers in the traditional organic soup scenario, there is no clear geochemical evidence to exclude the possibility that oxygen was present in the Earth’s atmosphere soon after the formation of its crust."

All of this evidence supports the fact that there was abundant oxygen on the early earth. However, with or without oxygen, evolution is in a no-win situation. Spontaneous generation could not have occurred either with oxygen—or without it!

http://www.jashow.org/wiki/index.php?title=The_Creation_Debate-Part_6

oxygen is very devastating to the origin of life experiments. For example, that Stanley Miller experiment where he had methane, ammonia, hydrogen and a spark in that chamber, if you introduced some oxygen in there with that spark, it would combine with the hydrogen and you would have a great explosion. You would not make the final product. In other words, in the presence of oxygen, these organic molecules do not form.

Many geologists who study the sedimentary deposits deep in the earth are pretty much agreeing that the atmospheric level of oxygen is pretty much the same as today. Even those urananite deposits in South Africa, for example, were thought to show a lower oxygen level have now been interpreted in terms of pretty much standard modern atmosphere.

http://www.biblicalcreation.org.uk/scientific_issues/bcs074.html

Ohmoto, H. 1996. Evidence in pre-2.2 Ga paleosols for the early evolution of atmospheric oxygen and terrestrial biota. Geology, 24(12), 1135-1138.

http://geology.gsapubs.org/content/24/12/1135.abstract

"Terrestrial biomass on the early continents may have been more extensive than previously recognised"



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7The earth's  atmosphere   Empty Re: The earth's atmosphere Mon Mar 30, 2015 3:23 pm

Otangelo


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http://creation.com/origin-of-oxygen-more-complex-than-imagined

In essence the author admits that within an evolutionary framework the data is contradictory, and no resolution of the contradictions is in sight, hence the need for ‘creative thinking’.

However, it is the naturalistic evolutionary framework that is the problem. Within this framework a reducing atmosphere is needed initially if the first cell is to have any possibility of arising by chance.3 But it must then change into an oxidizing atmosphere to permit the evolution of aerobic bacteria and multi-cellular life.

These problems disappear when the problem is approached from a biblical framework. There never was a great oxidation event because oxygen, at concentrations necessary for life to flourish, was present in the atmosphere during Creation week at the beginning. The geological evidence, including sulfur minerals and carbonate rocks, is explained by deposition during the early part of the global Flood.


http://creation.com/origin-of-oxygen-more-complex-than-imagined

there is now substantial evidence against these interdependent concepts. Dimroth and Kimberley10 unequivocally state:

   ‘in general, we find no evidence in the sedimentary distributions of carbon, sulfur, uranium or iron, that an oxygen-free atmosphere has existed at any time during the span of geological history recorded in well preserved sedimentary rocks’ (emphasis mine).

They went on to explain that:

   ‘the sedimentary distributions of carbon, sulfur, uranium, and ferric and ferrous iron depend greatly upon ambient oxygen pressure and should reflect any major change in proportion of oxygen in the atmosphere or hydrosphere. The similar distributions of these elements in sedimentary rocks of all ages are here interpreted to indicate the existence of a Precambrian atmosphere containing much oxygen.’

Elsewhere11 they concluded:

   ‘we know of no evidence which proves orders-of-magnitude differences between Middle Archaean and subsequent atmospheric compositions, hydrospheric compositions, or total biomasses.’

Dimroth and Kimberley concluded that the distributions of carbon, sulfur, uranium and iron in Precambrian sedimentary rocks are similar to those in Phanerozoic sedimentary rocks, and that therefore the earth’s atmosphere has always been oxidizing. This conclusion is devastating to all theories of chemical evolution which require a reducing atmosphere, and it has important implications for the Biblical creation-flood model.

III.  Can Researchers Recreate Ancient Bacteria?

http://www.dailytech.com/Scientists+Show+Evidence+of+How+Earth+Got+Its+Oxygen/article31853.htm

Much work remains, though, in formulating what kinds of organic reactions the manganese oxidation may have directly driven.  Comments Prof. Fisher:

I think that there will be a number of additional experiments that people will now attempt to try and reverse engineer a manganese photosynthetic photosystem or cell.

Once you know that this happened, it all of a sudden gives you reason to take more seriously an experimental program aimed at asking, 'Can we make a photosystem that's able to oxidize manganese but doesn't then go on to split water? How does it behave, and what is its chemistry?'

Even though we know what modern water splitting is and what it looks like, we still don't know exactly how it works. There is a still a major discovery to be made to find out exactly how the catalysis works, and now knowing where this machinery comes from may open new perspectives into its function -- an understanding that could help target technologies for energy production from artificial photosynthesis.

If the team can provide further evidence they could prove that bacteria first learned evolved a chain of enzymes to use sunlight to drive oxidation of manganese, before eventually acquiring more enzymes that allowed the splitting of water, improving the efficiency of the process, while allowing for the creation of an oxygen atmosphere and the high-density energy storage needed for multicellular life.


Manganese-oxidizing photosynthesis before the rise of cyanobacteria


Iron Oxides:
Fe2O3 (hematite) is an oxidized molecule of iron and is believed to form in an atmosphere containing free oxygen. It has been found in sediments reportedly greater than 2.5 billion years old by evolutionary considerations and in immense hematite deposits as far back as 3.4 billion years ago. The reduced form Fe3O4 (magnetite) has been found in recently formed deposits of 400 to 500 million years ago. The fact that all oxidation states of iron have been found in every "age" of deposits leads to the conclusion that both oxidizing and reducing environments have coexisted contemporaneously throughout earth's history, but in separate spaces.

Uranium Oxides:
Mineral deposits of uraninite (UO2), galena (PbS), pyrite (FeS2) and gold have been found in supposed 2.5 billion year old sedimentary rocks in South Africa. Uniform well-rounded grains of the minerals are evidence of their being deposited downstream from their original granite source. Is this evidence that the minerals were deposited during a time of a reducing atmosphere free of oxygen?
At first glance, the very idea of being washed downstream to a distance deposition site would seem to indicate that the grains had ample opportunity to be in contact with free O2 if it existed in the atmosphere during the time it was deposited. However, if the stream was moving very rapidly, the minerals may not have had time to come to equilibrium with the atmosphere before being deposited. This deposition was probably not rapid based on the amount of wear on each grain and the amount of sorting found in the layers. The deposits could also have been transported during glacial periods. There is some evidence of glacial formations in that area of South Africa supposed 2.5 billion years ago. The corresponding lack of contact with the atmosphere and the cold temperatures would have greatly reduced the reaction with O2 even in the presence of significant levels of O2 at that time.
Conclusion
There are several reasons to believe the earth's atmosphere has always contained oxygen, while small pockets of anoxic environments coexisted. First, photodissociation of water could have produced up to 10% of current levels of free oxygen. Second, oxidized mineral species of rocks have been dated as old as supposed 3.5 billion years old. Third, the presence of reduced minerals does not necessarily confirm that the environment was anoxic during their formation. Fourth, evidence of oxygen-producing life forms have been found in rocks more than supposed 3.5 billion years old.
After examining the geological evidence, the scientific community is starting to concede that the primitive earth's atmosphere was less reducing than first estimated, and that it may have even been oxidizing. Some chemical evolution experiments have been redone using more neutral (intermediate between reduced and oxidized) atmospheres than the initial experiments. "These experiments have generally yielded products in smaller quantities and less diversity than comparable experiments under more reducing conditions."

http://www.pnas.org/content/early/2013/06/20/1305530110
http://www.mandley.com/advdemo/mod06/adv6310.htm



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8The earth's  atmosphere   Empty Re: The earth's atmosphere Tue Aug 11, 2015 10:14 pm

Otangelo


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The Life and Death of Oxygen

http://creationsafaris.com/crev200810.htm

Oct 24, 2008 — The oxygen in our atmosphere has the energy equivalent of 20 thousand billion billion hydrogen bombs.  To maintain the oxygen level in our atmosphere, that amount of energy would have to be spent in manufacturing molecular oxygen every 4 million years (a thousandth the assumed age of the earth).
    Now that we have your attention, let’s think about the role of oxygen and life.  The statistics above were estimated by Paul G. Falkowski and Yukio Isozaki in Science this week.1  Unlike nitrogen, which is inert, oxygen is lively – it oxidizes, or burns things – not only in fire, but in cells, where the element must be handled gingerly by molecular machines to avoid damage.  That’s also why you take antioxidants in your food.  Keeping oxygen away from the primordial soup at the origin of life is understandably a serious problem (10/20/2008).
    Evolutionary biologists do not believe earth’s oxygen is primordial (i.e., that it formed when the earth formed).  They believe it was generated by living organisms when they evolved to use oxygen for electron capture in metabolism.  This conveniently keeps oxygen out of the picture at the origin of life (though some atmospheric oxygen forms spontaneously by the dissociation of water).  Oxygen could also be sequestered from the air in continental rocks: silicates, carbonates and sulfates.
    Oxygen reached levels of 10 to 30% only in the last 550 million years, evolutionists say.  Its 4-million-year lifetime is 0.4% the estimated 1 billion year lifetime of the atmosphere’s most abundant gas, nitrogen.  How did oxygen, with its relatively short lifetime, become the second most abundant gas in the atmosphere?  “The story is not as simple as it might first appear,” said Falkowski and Isozaki.  One has to calculate when and how it was first generated, and how it persists in its high concentration.
    Some oxygen is continuously formed by the breakup of water molecules by ultraviolet light in the atmosphere (at least till ozone forms and shields the upper atmosphere from excess UV).  If biology is the source, how does life produce it from water and minerals? 

The overwhelming source of O2 on Earth is photobiological oxidation of waterneither the evolution nor the mechanism of this process are completely understood.  Apparently it arose once in a single clade ofbacteria and was then appropriated via a single event, in which one cell engulfed another (endosymbiosis) to form a new symbiotic organism.  The latter became the progenitor of all photosynthetic eukaryotes, including algae and higher plants.
    The core of the oxidation machinery is photosystem II, a large protein complex containing four manganese atoms that are photocatalytically oxidized to create electron holes upstream.


They stressed that this “arose” once most likely because of the improbability that a “large protein complex” of “oxidation machinery” could arise by chance.  Nevertheless, assuming plants and bacteria produce it, the equation is balanced by the animals that consume it:

On time scales of years to millennia, these reactions are closely coupled to the reverse process of respiration, such that net production of O2 is virtually nil.  That is, without burial of organic matter in rocks, there would be very little free O2 in the atmosphere.  Hence, the evolution of oxygenic photosynthesis was a necessary but not a sufficient condition to oxidize Earth’s atmosphere.

So the second problem is getting molecular oxygen up to the level of 10-30% that has been maintained for 500 million years.  If a small amount is subducted into the mantle by plate tectonics, or captured in stable continental rocks, an atmospheric excess could be built up to a stable concentration without runaway production.  “The balance between burial of organic matter and its oxidation,” they said, “appears to have been tightly controlled over the past 500 million years.”  This balance requires an ongoing process of long-term storage within the earth.  The picture becomes complicated by the fact that volcanoes can re-release oxygen back into the atmosphere.  “The presence of O2 in the atmosphere requires an imbalance between oxygenic photosynthesis and aerobic respiration on time scales of millions of years,” they said; “hence, to generate an oxidized atmosphere, more organic matter must be buried than respired.”
    How well do scientists know how oxygen concentration has varied over geologic time?  “Perhaps surprisingly, not very well.”  Comparison of isotopes in carbonates and sulfates provide clues.  They believe the initial oxygen concentration produced by the first photosynthetic bacteria was quite low.  It rose when eukaryotes appeared, and then, according to the evolutionary timeline, became much more abundant in the Neoproterozoic – corresponding to the period just before the Cambrian Explosion.  The eukaryotic oxygen increase would have had to coincide with enhanced subduction in the lithosphere.
    Was the Cambrian Explosion a cause or effect of the rise of oxygen?  They suggested the latter: “The burial of large amounts of organic carbon over the past 750 million years is mirrored in a substantial rise in atmospheric O2,which may have triggered the Cambrian explosion of animal life.”
    Another balance of geology and biology would have had to occur in the Carboniferous.  The doubling of oxygen production by trees and ferns had to be balanced by “further increases in burial efficiency” they said.  How the continental plates coordinated their behavior with the evolution of plants, they did not say.  Throughout the remainder of earth history, this balance was maintained within comparatively narrow limits – 10 to 23%.  “The relativelynarrow range of variability suggests tight controls on the rate of burial and oxidation of organic matter on Earth’s surface.”  They did not say who or what is controlling these rates, other than to say that “the burial of organic carbon is roughly balanced by oxidation and weathering.”
    How valid is this story?  They think the broad picture is understood, but “the details remain sketchy” – particularly, how photosynthesis splits water, how oxygen concentration is controlled in the atmosphere.
    Could Woodward W. Fischer in Nature help the story?2  How good is the evidence to support the rise of the first photosynthetic bacteria?  “Go back to Archaean time, the interval of Earth’s history between about 4 billion and 2.5 billion years ago,” he began, “and we’re in largely unknown biological territory.
    While Fischer was concerned primarily with debunking claims of eukaryotes too early for comfort (i.e., before the rise of atmospheric oxygen), his report contained reason to doubt the validity of the timeline.  The new evidence may remove an embarrassing puzzle of how photosynthesis could arise 300 million years before the rise of atmospheric oxygen, but “does it close the gap between the morphological and molecular-fossil records of the evolution of eukaryotes?” he asked himself.  He answered himself, “Not yet.”  Other scientists are not conceding the debunking of 2.7-billion-year-old photosynthesis.  A news item about this on Nature News agrees the debate is far from over.
    For problems with oxygen at the birth of the solar system, see bullet one of the 09/24/2008 entry.

1.  Paul G. Falkowski and Yukio Isozaki, “The Story of O2,” Science, 24 October 2008: Vol. 322. no. 5901, pp. 540-542, DOI: 10.1126/science.1162641.
2.  Woodward W. Fischer, “Biogeochemistry: Life before the rise of oxygen,” Nature 455, 1051-1052 (23 October 2008) | doi:10.1038/4551051a.

OK; how convinced are you that the evolutionary storytellers are compelled by the evidence to embrace their billions of years saga of a history they cannot observe?  It’s a magical history, in which complex oxidation machines “arise” by some unspecified natural magic.  (Note that if something “arose once,” it is not following a natural law).
    Lacking evidence, they can build models that include the natural magic built-in.  By tweaking parameters here and there, and trying to debunk contrary evidence, they can get it to work – sort of.  It continues to amaze them how finely balanced it is.
    So much for this space fantasy.  The atmosphere on Darwin’s imaginary world is too rarefied to breathe.  Let’s head back to the real world. 



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9The earth's  atmosphere   Empty Re: The earth's atmosphere Sat Oct 24, 2015 8:31 am

Otangelo


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Atmospheric Oxygen Rules Out Evolution 1

WHEN we take a breath of air we do it for the purpose of providing oxygen to our body tissues. Without the continuous supply of this gas neither we nor the great majority of organisms on the earth could exist for more than a few minutes. It may come as a surprise, then, to learn that oxygen is potentially poisonous to all life forms. 1
As living organisms use oxygen several toxic products are formed. If these toxic products are not removed, destroyed, or rendered harmless the organisms will die. There are elaborate enzyme systems distributed throughout the oxygen-using organisms (aerobes) that render the toxic products of oxygen harmless.
A relatively small number of species do not have enzymatic systems to protect themselves from the toxic products of oxygen. Such organisms (anaerobes) can exist only in the absence of oxygen, for simple exposure to air quickly kills them. Anaerobic organisms, as a rule, are simpler in structure than aerobic ones. This is why evolutionists propose that they may be most like the first organism on earth. As a corollary, evolutionists postulate the existence of an oxygen-free atmosphere on the primitive earth. This primordial atmosphere would have consisted mainly of hydrogen, ammonia, methane, and water vapor. In contrast, our present atmosphere contains mostly oxygen (21 percent) and nitrogen (78 percent).
Although Pasteur's work in the past century laid to rest the idea that life could arise spontaneously from nonliving sources under current environmental conditions, by the middle of this century the topic of spontaneous generation of life once more became of major interest. In the past 25 years a number of laboratories throughout the world have been engaged in experiments to produce components of living cells under "primitive earth" conditions.
A measure of success has been achieved by these workers. When components of the postulated primitive earth's atmosphere were enclosed in a glass reaction vessel and its contents were irradiated with ultraviolet light or some other form of energy, biologically significant substances such as amino acids (the building blocks of proteins), purines, and pyrimidines (some of the components of the hereditary material); certain vitamins; and simple sugars were synthesized. To be sure, not all of these compounds were made in a given experiment, but the conditions were adjusted so as to favor the formation of a particular class of substances. Also, the quantities of products obtained were rather low. But the important point for this discussion is that in every successful experiment air or the gas oxygen was carefully excluded from the reaction vessel. On occasion when oxygen was included among the gaseous starting components, no biologically significant compounds were formed.2
 

Oxygen Enhances Breakdown of Organic Compounds

Oxygen does not only prevent the formation of biologically significant compounds in a "primitive earth" environment, it also can cause the modification and breakdown of already formed bio logical materials. We experience this, for example, when butter turns rancid, owing to the oxidation of its carbon compounds. The combination of even low levels of oxygen with ultraviolet light enhances the breakdown of biologically significant substances (organic compounds). Miller and Orgel, in their book The Origins of Life on the Earth, say that "it does not seem possible that organic compounds remained in the primitive ocean for any length of time after oxygen entered the earth's atmosphere. They are now present on the surface of the earth only because they are being continuously resynthesized by living organisms. Organic compounds occur below the surface of the earth, for example in coal and oil, because there the environment is anaerobic [without oxygen]." 4 Because of these facts, evolutionists assume that free oxygen was all but absent during a significant portion of the earth's "4.5-billion-year" history. It is considered to have been during this oxygen-free period that the first life forms are thought to have evolved.

According to the evolutionary model, the oxygen content in our atmosphere began to rise after the emergence of the first photosynthetic plants. 3 - 4 Photosynthesis is a complex process that converts the gas carbon dioxide and water into oxygen and sugar like compounds called carbohydrates. The energy needed for this work is harnessed from light. In this manner, some of the radiant energy of the sun is imprisoned into carbohydrates. This energy may be liberated later on when the carbohydrates are burned (for example, in the form of a log in the fireplace) or metabolized by an organism as food. When the carbohydrate is burned, and the energy imprisoned in its structure is released, oxygen of the air is consumed. In fact, exactly as much oxygen is used up when burning a certain quantity of carbohydrate as was produced during its photosynthesis. All plant material ever formed by photosynthesis is eventually broken down to carbon dioxide and water, except that which is buried in the crust of the earth. Estimates of the amount of organic carbon buried in the crust of the earth indicate that in the past there was produced about 15 times more oxygen than there is in our atmosphere at present.5 The excess amount presumably has been absorbed by "oxygen sink" processes, such as the oxidation of iron, sulfur, and volcanic gases. It would thus appear that the evolutionary scenario presented above is based on sound scientific reasoning.
However, additional considerations of the natural processes involved challenge the validity of this evolutionary scheme. Leigh Van Valen, a member of the committee on evolutionary biology at the University of Chicago, questions the notion of slow build-up of oxygen in our atmosphere.6 He indicates that photosynthesis by green plants may be an inadequate explanation for the early accumulation of oxygen. According to him the net production of oxygen today and throughout the period of abundant fossil production (0.6 billion years) is about equal to that absorbed by the continuous "oxygen sink" processes. How could there be any net oxygen accumulation in the atmosphere during an earlier period of presumably much less photosynthesis and larger "oxygen sink"?


Van Valen postulated several possible solutions to this problem, none of which were to his liking, and concluded: "The cause of the original rise in oxygen concentration presents a serious and unresolved quantitative problem." 6G. R. Carruthers, of the Naval Space Research Laboratory in Washington, D.C., pointed out an additional difficulty with the initial rise in atmospheric oxygen by green-plant photosynthesis. An atmosphere void of oxygen would not contain the ultraviolet-absorbing ozone layer. Any photosynthesizing organism, by definition, would be exposed to light radiation and doubtless would be destroyed by the lethal short-wavelength ultraviolet rays. 7 Ultraviolet radiation, on the other hand, plays an important role in the production of atmospheric oxygen. It has been known for some time that in the earth's upper atmosphere, above the ozone layer, molecules of water are shattered by the strong ultraviolet radiation of the sun. The eventual products of this reaction are atomic and molecular oxygen and hydrogen. Hydrogen is light enough to escape the earth's gravitational attraction, whereas oxygen remains. Calculations for the production of oxygen by the photodissociation of water vapor were made by R. T. Brinkman, of the California Institute of Technology, using certain assumptions where data were not available. He found that this process could produce 32 times the amount of oxygen currently found in our atmosphere and that a minimum of one-fourth of this atmospheric level of oxygen should have been present for more than 99 per cent of this earth's postulated evolutionary history. 8


These results were awarded a mixed reception because of their unfavorable implications for current evolutionary postulates. Then, pictures taken by a special camera placed on the surface of the moon during the Apollo 16 mission revealed that substantial amounts of hydrogen are leaving the earth's atmosphere, owing to the action of ultraviolet radiation on the water vapors of the upper atmosphere.9 This finding shows that the photodissociation of water is a significant physical reality and an important source of atmospheric oxygen. 10 The most recent measurements of this process indicate a rate of oxygen production about 5 times less than Brinkman's calculations, 11 but Carruthers, who directed the camera experiments during the Apollo 16 mission, indicates that in the past these rates probably were several times greater.7
In 1973 the Mariner 10 spacecraft flew by the planet Venus and radioed back to earth information about the composition of its upper atmosphere. Unexpectedly, the atomic oxygen content of the upper atmosphere of Venus was found to be similar to what it is on earth. 12 It is unlikely that oxygen is being produced on Venus via photosynthesis by plants, inasmuch as to our knowledge, this planet is devoid of any known forms of life. The substantial amount of oxygen on Venus is likely to come from the interaction of the sun's ultraviolet radiation with gaseous water vapor or with carbon dioxide. 13, 14 The importance of this observation rests in the undeniable demonstration that oxygen is produced in the absence of plants in a "primitive like" atmosphere.


Postulate No Longer Tenable

All available evidence taken together seems to indicate that it is no longer tenable to postulate the existence of long periods of an oxygen-free atmosphere at any time during the earth's history. The presence of oxygen in the atmosphere rules out the possibility of any biologically significant compounds' being formed in the "primitive atmosphere." This realization has forced some scientists to propose that "biological- building-block substances such as amino acids were actually brought to earth by meteorites." 15 This amounts to admitting their inability to postulate a scientifically valid mechanism that could yield even the simplest building blocks of biologically important substances in the context of chemical evolution. The concept of spontaneous generation of life is the only logical alternative to the Biblical account of Creation. Evolutionists, rejecting the Mosaic account of our origins as a myth, have enthusiastically advocated this other alternative. They have turned to the book of nature to gain support for their concepts. But "since the book of nature and the book of Revelation bear the impress of the same mastermind, they can not but speak in harmony. By different methods, and in different languages, they witness to the same great truths." 16
The validity of this statement is apparent when we consider the origins of atmospheric oxygen and the chances for the spontaneous generation of life. The book of nature tells us that if oxygen had always been in the atmosphere of our earth, life could not have come about by a slow step-by-step self-organization of matter, but rather through a creative act by the One who commanded that "the earth bring forth the living creature after his kind." 17


1) https://www.ministrymagazine.org/archive/1976/08/atmospheric-oxygen-rules-out-evolution



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10The earth's  atmosphere   Empty Re: The earth's atmosphere Sat Oct 24, 2015 8:52 am

Otangelo


Admin

The First atmosphere—geological evidences and their implications

In Ex Nihilo (v3n3, August 1980) David Denner discussed the composition of the Earth’s primitive atmosphere as advocated by evolutionists. He concluded that:

‘the reason for the widespread adherence to the belief in a primitive reducing atmosphere, in spite of much evidence to the contrary, is the same reason for which it was postulated. If you are to believe many of the theories of chemical evolution at all, you simply have to believe the Earth’s atmosphere was once radically different from its composition today.’

Most geologists accept the assertion that the early Earth had a reducing atmosphere. The concept that the Archaean (> 2.3 billion Arbitrary Geologic Years (A.G.Yr.3) atmosphere contained practically no free oxygen has had its roots in the threefold division of the geological column based on abundance of macrofossils: Phanerozoic (Cambrian to Recent), Oroterozoic, and Archaean. Lack of obvious Archaean life has popularly been attributed to a hostile environment rich in toxic, reduced volcanic gases. Lack of Archaean sulfates and red beds has similarly been attributed to peculiar atmospheric and hydrospheric compositions. These arguments have been convincingly presented by scientists such as Cloud,1,2 Eriksson and Truswell,3 and Schidlowski.4 The strongest support for an oxygen-poor Archaean atmosphere came with Holland’s5 calculation of the maximum partial pressure of oxygen for uraninite (UO2) stability, and his interpretation that the Archaean uraninite placer deposits of the Witwatersrand, South Africa, and Elliot Lake, Canada, could not have formed under a significantly oxidizing atmosphere. This was followed by a variety of genetic models for the formation of the ubiquitous Archaean banded iron formations, such models depending upon an oxygen-poor atmosphere.6,7,8,9
However, there is now substantial evidence against these interdependent concepts. Dimroth and Kimberley10 unequivocally state:

‘in general, we find no evidence in the sedimentary distributions of carbon, sulfur, uranium or iron, that an oxygen-free atmosphere has existed at any time during the span of geological history recorded in well preserved sedimentary rocks’ (emphasis mine).

They went on to explain that:

‘the sedimentary distributions of carbon, sulfur, uranium, and ferric and ferrous iron depend greatly upon ambient oxygen pressure and should reflect any major change in proportion of oxygen in the atmosphere or hydrosphere. The similar distributions of these elements in sedimentary rocks of all ages are here interpreted to indicate the existence of a Precambrian atmosphere containing much oxygen.’

Elsewhere11 they concluded:

‘we know of no evidence which proves orders-of-magnitude differences between Middle Archaean and subsequent atmospheric compositions, hydrospheric compositions, or total biomasses.’

Sedimentary carbon


Dimroth and Kimberley10 found that:

‘organic carbon contents and distributions are similar in Precambrian and Quaternary sedimentary rocks and sediments, although distributions in both would have been sensitive to variations in rates of organic productivity and atmospheric oxygen pressure.’

Carbon occurs in two ways in sedimentary rocks:

(a) within the carbonate radical of carbonate minerals, and
(b) in a myriad of organic compounds. The latter is termed organic carbon and is the decay product of living matter. It is found even in Archaean rocks.11 Organic carbon compounds are found in virtually all well preserved shales and mudstones of any age.10

Abundant Archaean organic carbon is a residual product of photosynthetic oxygen production. Microorganisms have been reported from carbonaceous rocks of the Fig Tree Group of Swaziland (3.4 billion A.G.Yr. old)12 and blue-green algae remains occur in the 2.6 billion A.G. Yr. old Veal Reef Carbon Seam of the Witwatersrand Sequence.13 Archaean and Lower Proterozoic shales and mudstones sampled to date average 0.7 wt % and 1.6 wt. % organic carbon respectively.14 This compares with the average amount of 0.5 wt. % organic carbon in Phanerozoic shales and mudstones.15
Furthermore the spatial pattern of Archaean—carbon distribution does not differ in any obvious way from that of the Late Precambrian or Phanerozoic.11 This rules out the possibility that Archaean sediments repeatedly survived weathering and resedimentation cycles as a result of any postulated low rate of atmospheric oxygen production. An even stronger argument against this recycling of organic carbon is the strong correlation, obvious in the field, between organic carbon and pyrite (FeS2) contents in all Precambrian sedimentary rocks, particularly in Archaean rocks.10 Since diagenetic pyrite formation depends upon the presence of readily metabolizable organic compounds,16 it is clear that this organic carbon was in organic matter not long dead at the time of deposition.
Not only is the mass distribution of carbon between organic molecules and carbonate minerals relevant to atmospheric oxygen levels but also isotopic fractionation between these two reservoirs.17 In the hydrosphere-atmosphere system comparable organic and carbonate carbon isotopic ratios in sedimentary rocks of all ages would indicate a consent rate of separation between the two reservoirs, and hence an unchanging rate of free oxygen production. Available analyses indeed indicate constancy with time for the isotopic ratios of sedimentary carbonate and organic carbon.18,19,20,21 After discounting the effects of additional carbon supplied in volcanic emissions, Demroth and Kimberley10 still concluded that:

‘the constancy of carbon isotopic fractionation in sedimentary rocks is, in fact, an indication of relative constancy of free-oxygen production’

and thus the composition of the Archaean atmosphere was similar to that of the present day atmosphere.

Sedimentary sulfur


Kimberley and Dimroth11 found that:

‘the distribution of sulfur in Archaean and Proterozoic rocks is similar to that in Phanerozoic rocks of comparable type.’

The distribution of sulfur in recent sediments, like that of organic carbon, is largely a function of primary and diagenetic redox reactions16and is correspondingly sensitive to variations in atmospheric oxygen pressure. There are two major sources of sulfide sulfur in present-day sediments—seawater sulfate reduced bacterially and organic sulfur released during decay; and two minor sources—volcanically exhaled sulfur and detrital pyrite.
The preservation potential of detrital pyrite in present day sedimentary environments is now being eliminated largely by biochemical oxidation and oxidative corrosion. In a few cases, detrital pyrite may survive diagenesis, provided deposition is rapid and reducing biogenic conditions are established rapidly after deposition. By contrast, pyrite should have been a consistent and important component of sediments deposited under a hypothetical oxygen-deficient atmosphere. Pyrite is common in all source rocks but detrital pyrite is just as rare in Proterozoic and Archaean sedimentary rocks as it is in present day sediments. Absence of pyrite from many Proterozoic and Archaean sandstones, for instance, despite the common presence of the mineral in the source rocks, is evidence for oxidation during transport and/or diagenesis.

Part Two


Most sulfide sulfur in recent sediments has formed by the action of sulphate-reducing bacteria and is closely associated with bituminous and carbonaceous shales. Sedimentary pyrite is almost invariably closely associated with organic carbon in sedimentary rocks of any age. Some Precambrian pyrite occurs as laminae like some of the recent diagenetic pyrite,16 but much is nodular, more obviously diagenetic. Carbonaceous snares and mudstones of all ages are richly pyritic and basal sandstones of all elastic sequences are commonly cemented by pyrite.11 Pyrite content increases linearly with increasing organic carbon content in Archaean shales and mudstones, a similar relationship to that seen in sulfur and carbon contents.14 This consistency of the sulfide sulphur-carbonaceous shale/mudstone association, which is so characteristic of Precambrian as well as Phanerozoic rock associations, is evident for:

(a) the continually abundant presence of sulfate in the oceans and
(b) the continual diagenetic bacterial reduction of that sulfate, since deposition of the earliest known Precambrian sediment.10

Volcanic exhalations generally include hydrogen sulfide gas. Under present conditions most of the exhaled hydrogen sulfide is rapidly oxidized and precipitation of heavy metal sulfides occurs only under exceptional conditions. In the presence of atmospheric oxygen, the products of volcanic exhalation would have differed, particularly if it is assumed most of the primordial ocean had been saturated with respect to siderite (FeCO3).7–9 All hydrogen sulfide exhaled by submarine volcanos would have precipitated as iron sulfide close to the volcanic vents. Volcanoaenic sulfide deposits should be many orders of magnitude more voluminous in Precambrian volcanic sequences than in Phanerozoic volcanic sequences, and they should occur around all Archaean submarine volcanic centers. In fact, none of these or other inferred differences between volcanogenic sulfide deposits of Precambrian and Phanerozoic age are consistently found.10 Massive sulfide deposits certainly did not form around every Archaean volcanic center nor do Archaean sulfide deposits appear to be more voluminous than sulfide deposits in comparable Phanerozoic volcanic belts. The distribution of volcanic exhalation sulfide deposits in Archaean terrains does not appear to differ substantially from the Phanerozoic distribution, and the hypothesis that the Early Precambrian primordial ocean was saturated with respect to siderite is similarly unsubstantiated.10
Scarcity of Precambrian evaporites has been cited as evidence against substantial sulfate concentrations in sea water and an oxidizing atmosphere. However, most Archaean sedimentary rocks are in sequences which do not normally contain evaporites. Most Archaean sedimentation apparently occurred on tectonically active, steep slopes surrounding volcanic piles, a setting not conducive to evaporite deposition or preservation.10 On the other hand, there is now abundant evidence that evaporites were present in many Proterozoic sequences, for example, in Northern Australia.22,23 Survival of the actual evaporite minerals is claimed to be rare in Precambrian sediments because presently exposed rocks have been fairly close to the surface since the end of Precambrian time and have experienced prolonged groundwater flow. In conclusion, the apparent disproportionate distribution of evaporites between Archaean, Proterozoic, and Phanerozoic sedimentary sequences cannot be used as an argument in favor of a primitive reducing atmosphere.

Uranium


One of the strongest arguments used to support the theory of a primitive reducing atmosphere is the character of uranium deposition, which is presumed to have changed with time, resulting in the apparent time-related or time-bound occurrence of the various types of uranium deposits.24,25
Based on Holland’s5 calculation of the maximum partial pressure of oxygen for uraninite (UO2) stability, it was concluded that the Archaean uraninite placer deposits of the Witwatersrand, South Africa and Elliot Lake, Canada could not have formed under a significantly oxidizing atmosphere. While controversy regarding the origin of these two deposits has raged for many years, most geologists now accept the placer hypothesis whereby detrital uraninite was deposited in the quartz pebble conglomerates of alluvial fan or placer under reducing atmospheric conditions. It is argued that because the uraninite appears to be detrital and only stable under reducing conditions, then atmospheric conditions, at the time of transport and deposition must have been reducing.25,26 However, the remarkable similarity between the subeconomic concentrations of detrital uraninite in the present day Indus Valley27 and that of the Witwatersrand, as well as other evidence, invalidates any such concept.

‘It would appear quite unnecessary to postulate a reducing atmosphere for the transportation of detrital uraninite.’28

Furthermore, Kimberley and Dimroth10,11 present evidence against this placer hypothesis, comparing many of the characteristics of other major uranium occurrences undisputably deposited under oxygen-rich atmospheric conditions to those of the Witwatersrand and Elliot Lake ores. Direct evidence of mobility of uranium in solution has been found in uranite-replaced organisms within Witwatersrand ores,29 which negates the case for a reducing atmosphere put by Robertson et al,25 as seen in the diagram.

The earth's  atmosphere   P50_atmosphere

Dimroth and Kimberley conclude:

‘Although it is thermodynamically possible that this mobility could have occurred at exceedingly low oxygen pressures, it is more likely that the carbonaceous replacements indicate an oxygenic groundwater atmosphere system more like that at present.’10

Similarly Simpson and Bowles28 state:

‘the retention of sulfate and uranyl ions in solution … suggests that the atmosphere was oxidizing at the time of deposition.’

In reality, therefore, the distribution of uranium deposits within sediments of all ages has nothing to do with changes in atmospheric conditions which were oxidizing throughout the Phanerozoic, Proterozoic and the Archaean. Rather the distribution is dependent on the availability of uranium in the sediment source rocks.

‘The high uranium content of crystalline Archaean source rocks is the probable main reason for uranium concentrations in the Lower Proterozoic, Tertiary mantles on uplifted, crystalline Precambrian rocks like the Shirley Basin of Wyoming are similarly rich in stratiform deposits of uraninite.’11

Conclusion and implications


Dimroth and Kimberley10 concluded that the distributions of carbon, sulfur, uranium and iron in Precambrian sedimentary rocks are similar to those in Phanerozoic sedimentary rocks, and that therefore the earth’s atmosphere has always been oxidizing. This conclusion is devastating to all theories of chemical evolution which require a reducing atmosphere, and it has important implications for the Biblical creation-flood model.
First and foremost the abundance of organic carbon in so-called Archaean and Proterozoic sedimentary rocks is initially surprising, but also suggests that these rocks, including many metamorphic (ex-sedimentary) rocks, were also deposited during the Biblical Flood. We must remember that the geological column and associated time-scale is itself assumptive, so that flood geology need not be bound to the same depositional order of strata and certainly cannot adopt the same nomenclature and terminology. These organic carbon-rich Archaean and Proterozoic sedimentary rocks contain the remains of life, albeit microscopic life by the myriads, and algae, destroyed in the same catastrophe as the invertebrates and vertebrates of the so-called Phanerozoic. The terms Archaean and Proterozoic only place these rocks early within the evolutionary time-scale, a position rejected by flood geologists.
Secondly, the similar distribution of carbon, sulfur, uranium and iron within sedimentary rocks of all uniformitarian geological ages is in fact more compatible with the flood geology model in which all fossiliferous sedimentary rocks and associated strata were deposited during the Biblical Flood and since. Because the created atmosphere has always been oxygen rich (in the Garden of Eden as well as during the Flood) it is to be expected that the nature and chemistry of the Flood sediments would reflect this.
Thirdly, since Precambrian sedimentary and metamorphic rocks contain globally important ore deposits these same ores were either deposited as an integral part of the enclosing sediments during the Flood, or, as in the case of some uranium ores, formed during or after the Flood following deposition of the sediments which enclose them.
Finally, these conclusions and implications are in direct conflict with the uniformitarian geological time scale. This conflict is highlighted by the many radiometric age dates for these rocks and ores (particularly uranium ores). What I am asserting is that all major fossiliferous strata, regardless of their geologic age, were deposited during the Biblical Flood about 5,000 years ago or consequent to it, and that the evidence is entirely consistent with this thesis.


  • Earliest multicellular life?


[1]Cloud, P.E., Sci. 160 729, (1968). Return to Text

[2]Cloud, P.E., Am. J. Sci. 272 537, (1972). Return to Text

[3]Eriksson, K.A. & Truswell, J.F., in Evolution of the Earth’s Crust, D.H. Tarling (ed.) ch 6 219, (1979). Return to Text

[4]Schidlowski, M., in The Early History of the Earth’s Crust, B.F. Windley (ed.) Wiley, New York, 525, (1976). Return to Text

[5]Holland, H.D., in "Petrologic Studies". Geol. Soc. Am. Buddington 447, (1962). Return to Text

[6]Lepp, H. & Goldich, S.S. Exon. Geol. 59 1025, (1964). Return to Text

[7]Cloud, P.E., Econ. Geol. 68 1135, (1973). Return to Text

[8]Holland, H.D., Econ. Geol. 68 1169, (1973). Return to Text

[9]Drever, J.J., Geol. Soc. Am. Bull. 85 1099, (1974). Return to Text

[10]Dimroth, E. & Kimberley, M.M., Can. J. Earth Sci. 13 1161, (1976). Return to Text

[11]Kimberley, M.M. & Dimroth, E., in The Early History of the Earth, B.F. Windley (ed.) Wiley, N.Y. Return to Text

[12]Pflug, H.D., Econ Geol. Res. Unit, Witwatersrand Univ., Inform Circ, No. 28, (1966). Return to Text

[13]Nagy, L.A., Geol. Soc. Am., Abstracts with Programs 7(7) 1209, (1975). Return to Text

[14]Cameron, E.M. & Johassen, T.R. Geochem. Cosmochim. Acta 36 985, (1972). Return to Text

[15]Ronov, A.B., Geochemistry 5 510, (1958). Return to Text

[16]Berner, R.A., Chemical Sedimentology McGraw-Hill, (1971). Return to Text

[17]Broeker, W.S., J. Geophys. Res. 75 3553, (1970). Return to Text

[18]Becker, R.H. & Clayton, R.N., Geochem. Cosmochim. Acta 36 577, (1972). Return to Text

[19]Moore, C.B., Lewis, C.F. & Kvenvolden, K.A., Precambrian Res. 1 49, (1974). Return to Text

[20]Nagy, B., Kunen, S.M., Zumberge, J.E., Long, A., Moore, C.B., Lewis, C.F., Anhausser, C.R. & Pretorius, D.A., Precambrian Res. 1 43, (1074). Return to Text

[21]Schidlowski, M., Eichmann, A. & Junge, C.E., Precambrian Res. 2 1, (1975). Return to Text

[22]Crick, I.H. & Muir, M.D., in Uranium in the Pine Creek Geosyncline. Internat. Atomic Energy Agency, Vienna, 531, (1980). Return to Text

[23]Muir, M.D., BMR J. Aust. Geol. & Geophys. 4 149, (1979). Return to Text

[24]Dahlkamp, F.J., Mineral Deposits 15 69, (1980). Return to Text

[25]Robertson, D.S., Tilsley, J.E. & Hogg, G.M., Econ. Geol. 73 1409, (1978). Return to Text

[26]Grandstaff, D.W., Trans. Geol. Soc. S. Afr. 77 291, (1975). Return to Text

[27]Zeschke, G., Trans. Geol. Soc, S. Afr. 63 87, (1961). Return to Text

[28]Simpson, P.R. & Bowles, J.F.W., Phil. Trans. R. Soc. Lond. A 286 527, (1977). Return to Text

[29]Hallbauer, D.K. & Van Warmelo, K.T., Precambrian Res. 1 199, (1974). Return to Text

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11The earth's  atmosphere   Empty Re: The earth's atmosphere Sat Oct 24, 2015 9:12 am

Otangelo


Admin

THE MYTH OF THE PRE-BIOTIC ATMOSPHERE 1


The Oxygen Problem
     The atmospheric conditions proposed by Oparin, Haldane and Urey were radically different from what presently exists. Because oxygen destroys the chemical building blocks of life, they speculated that the early earth had an oxygen-free atmosphere. However, in the last twenty years, evidence has surfaced that has convinced most atmospheric scientists that the early atmosphere contained abundant oxygen.
     In the 1970's Apollo 16 astronauts discovered that water is broken down into oxygen and hydrogen gas in the upper atmosphere when it is bombarded by ultraviolet radiation. This process, called photo dissociation, is an efficient process which would have resulted in the production of large quantities of oxygen in a relatively short time. Studies by the astronauts revealed that this process is probably a major source of oxygen in our current atmosphere. 2 H2O + uv Radiation -- H2 (hydrogen gas) + O2 (oxygen gas)
     The assumption of an oxygen-free atmosphere has also been rejected on theoretical grounds. The ozone layer around planet earth consists of a thin but critical blanket of oxygen gas in the upper atmosphere. This layer of oxygen gas blocks deadly levels of ultraviolet radiation from the sun.9Without oxygen in the early atmosphere, there could have been no ozone layer over that early earth. Without an ozone layer, all life on the surface of planet earth would face certain death from exposure to intense ultraviolet radiation. Furthermore, the chemical building blocks of proteins, RNA and DNA, would be quickly annihilated because ultraviolet radiation destroys their chemical bonds.10 It doesn't matter if these newly formed building blocks are in the atmosphere, on dry ground, or under water.11,12,13
     So we have a major dilemma. The products of the Miller-Urey experiments would be destroyed if oxygen was present, and they would be destroyed if it wasn't! This "catch 22" has been noted by evolutionist and molecular biologist Michael Denton:
     "What we have then is a sort of 'Catch 22' situation. If we have oxygen we have no organic compounds, but if we don't we have none either."14
     Even if the building blocks of life could survive the effects of intense ultraviolet radiation and form life spontaneously, the survival of any subsequent life forms would be very doubtful in the presence of such heavy ultraviolet light. Ozone must be present to protect any surface life from the deadly effects of ultraviolet radiation from the sun.
     Finally, the assumption that there was no oxygen in the early atmosphere is not borne out by the geologic evidence. Geologists have discovered evidence of abundant oxygen content in the oldest known rocks on earth. Again, Michael Denton:
     "Ominously, for believers in the traditional organic soup scenario, there is no clear geochemical evidence to exclude the possibility that oxygen was present in the Earth's atmosphere soon after the formation of its crust."15
     All of this evidence supports the fact that there was abundant oxygen on the early earth.
Ammonia and Methane Short Lived
     The assumption of an atmosphere consisting mainly of ammonia, methane, and hydrogen, has also been seriously questioned. In the 1970's scientists concluded that ultraviolet radiation from the sun, as well as simple "rainout," would eliminate ammonia and methane from the upper atmosphere in a very short time.16 In 1981, Atmospheric scientists from NASA concluded that:
     "the methane and ammonia-dominated atmosphere would have been very short lived, if it ever existed at all."17

1) http://xwalk.ca/origin.html



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12The earth's  atmosphere   Empty Re: The earth's atmosphere Wed Dec 02, 2015 9:54 am

Otangelo


Admin

[quote="mat-in" postid=2033816] Deine "Quelle" Zitiert da Literatur von 1971... [/quote]

Das Buch von Koonin ist von 2011, und ist SEKULAR. Dh, kein Kreationistenbuch.....

Aber vielleicht koenntest du erklaeren, wie du dir folgendes vorstellst von einem rein technischen standpunkt aus : Wie gezeigt, ist jedes der 20 Proteine und Proteinkomplexe unerlaesslich , und auch eine maximal zulaessliche mutationsrate. Wenn diese ueberschritten wird, ist DNA replikation nicht moeglich. Die Zelle stirbt. Wurden die 20 Proteine aus zufall genau spezifiziert, damit sie genau interagieren koennen, zusammenpassen, und der produktionablauf , wurde der durch zufall programmiert ? Wie kamen die Proteine in der richtigen sequenz zusammen ? Wie wurden sie zusammengeknuepft ohne katalisatoren ?

http://reasonandscience.heavenforum.org/t2024-the-rna-world-and-the-origins-of-life#3414

In order to copy RNA, fragments or monomers (individual building blocks) that have 5'-triphosphates must be ligated together. This is true for modern (protein-based) polymerases, and is also the most likely mechanism by which a ribozyme self-replicase in an RNA world might function. Yet no one has found a natural ribozyme that can perform this reaction.

Welches waren die chancen, dass alle richtigen materialien am richtigen Zeitpunkt am richtigen Ort vorhanden waren? Wie kam es, dass alle linkshaendigen Aminosäuren am Ort vorhanden waren, wenn natuerlich links und rechthaendige produziert werden im verhaeltnis 50%/50% ? Ausserdem: Wenn es Sauerstoff gab in der Atmosphaere, dann wuerde dieser die Aminosäuren zerstoeren. Gaebe es keinen, wuerden die UV Strahlen dies tun.....

http://reasonandscience.heavenforum.org/t1556-the-earth-s-atmosphere?highlight=oxygen

There is a problem if you consider the ozone (O3) layer which protects the earth from ultraviolet rays. Without this layer, organic molecules would be broken down and life would soon be eliminated. But if you have oxygen, it prevents life from starting. A "catch-22" situation (Denton 1985, 261-262):

Atmosphere with oxygen => No amino acids => No life possible!
Atmosphere without oxygen => No ozone => No life possible!


meinst Du nicht, da hat sich mittlerweile was getan? Zudem deine Quelle(n) ohnehin ziemlich zusammenhangslos zitieren, siehe das pubmed gelistete Meinungswerk zur RNA Welt bei der allein der Titel aber nicht der Inhalt die These stützte. Ich glaube der Hauptgrund warum wir hier streiten ist, das Du bei dem Jahrhundertedauernden "Rückzugsgefecht" einfach noch nicht auf dem neuesten Stand bist. Vor 200 Jahren war es "die Planeten drehen sich (um die Sonne), das hat Gott gemacht"... heute würde das niemand mehr sagen.

haha. Dann schau doch mal, was fuer antworten es da gibt auf diese Frage...... Was Newton geschrieben hat, gilt noch heute.

In the book, The Truth: God or evolution? Marshall and Sandra Hall describe an often quoted exchange between Newton and an atheist friend.

http://reasonandscience.heavenforum.org/t1939-isaac-newton?highlight=newton

“ Sir Isaac had an accomplished artisan fashion for him a small scale model of our solar system, which was to be put in a room in Newton's home when completed. The assignment was finished and installed on a large table. The workman had done a very commendable job, simulating not only the various sizes of the planets and their relative proximities, but also so constructing the model that everything rotated and orbited when a crank was turned. It was an interesting, even fascinating work, as you can imagine, particularly to anyone schooled in the sciences.
Newton's atheist-scientist friend came by for a visit. Seeing the model, he was naturally intrigued, and proceeded to examine it with undisguised admiration for the high quality of the workmanship. "My, what an exquisite thing this is!" he exclaimed. "Who made it?"
Paying little attention to him, Sir Isaac answered, "Nobody." Stopping his inspection, the visitor turned and said, "Evidently you did not understand my question. I asked who made this." Newton, enjoying himself immensely no doubt, replied in a still more serious tone, "Nobody. What you see just happened to assume the form it now has." "You must think I am a fool!" the visitor retorted heatedly, "Of course somebody made it, and he is a genius, and I would like to know who he is!" Newton then spoke to his friend in a polite yet firm way: "This thing is but a puny imitation of a much grander system whose laws you know, and I am not able to convince you that this mere toy is without a designer or maker; yet you profess to believe that the great original from which the design is taken has come into being without either designer or maker! Now tell me by what sort of reasoning do you reach such an incongruous conclusion?"



Vor 10 Jahren war es "sowas kompliziertes wie das Flagellum von Bakterien mit über 30 Einzelkomponenten die alleine keinen Sinn machen, das muß Gott gemacht haben"... das sagt heute auch keiner mehr, *jede* der Komponenten hat eine Einzelne Funktion und einige der Komponenten in Verbindung miteinander auch schon. Dann vor vielleicht 5 Jahren war es "Aber die DNA-Replikation..." blabla, gleiche Geschichte. Die Dinge bei der die moderne Wissenschaft heute mit den Schultern zucken müßte und sagen würde: "Da haben wir noch keine Idee wie es funktioniert, meinetwegen nenne es für die nächsten 5 Jahre "Gott" bis wir es dann erklären können" sind ganz andere. Die gibt es, aber auch sich auf die zu stürzen ist ... dumm. Das haben z.B. auch die Theologen im Vatikan eingesehen und ein "god of the gaps" wird mit jedem Jahr kleiner, weniger, unwichtiger und die Argumente des Vorjahres lächerlicher.

Außerdem scheinst Du ein vollkommenes Unverständniss zu haben was eine Hypothese, was eine Theorie und was "blanker Schmarn" ist. Das schöne an einer Hypothese ist doch, dass ich sie überprüfen kann, ich widerlege oder bestätige sie. Wenn Sie nur in Teilen richtig war bessere ich nach und versuche mich wieder am bestätigen und widerlegen. So wird unser - schon von Natur aus nie perfekt sein könnendes - Verständnis der Vorgänge um uns herum immer präziser, besser, genauer. Das hat nichts mit "glauben" zu tun. Es ist nun mal die beste Erklärung die wir haben und wenn ich finde da stimmt was nicht formuliere ich eine neue und *überprüfe* diese, ist sie nicht besser, wird sie verworfen. Dein "blanker Schmarn" hingegen stellt Behauptungen in den Raum, fordert ein Ende des Nachdenkens, ist nicht nur nicht überprüfbar - und damit untauglich - sondern im Gegenteil, in diesen ganzen wirren Büchern alter Hirtenkulturen wird ja sogar gesagt, das man gegenteilige Beweise ignorieren soll! Hätten wir das getan, würden wir heute noch in Höhlen wohnen und nur Feuer haben wenn mal der Blitz eingeschlagen ist. Wir haben keine Smartphones oder Antibiotika, weil wir dafür gebetet haben, nicht weil sie irgend ein Schöpfer gemacht hat, sondern weil wir beim Erkennen des Zusammenhangs zwischen magnetfeld und elektrischem Strom nicht vor Ehrfurcht im Boden versunken sind, gesagt haben "das macht Gott" und aufgehört haben nachzudenken. Weil wir nicht gedacht haben "da hat der Schöpfer die Pilze aber lieber als die Bakterien und denen geholfen auf der verschimmelten Agagrplatte zu überleben", sondern weil wir dem auf den Grund gegangen sind und es verstanden haben.

Es wird nichts in ein "kein Gott notwendig" Gedankenbild gepreßt. Es wird ein Weltbild konstruiert und das stößt eben irgend wo an seine Grenzen. Das weckt dann unsere Neugier (oder wir haben Angst vor diesem Unwissen) und wir forschen, bis wir es verstehen (oder geben faul und verängstigt das Denken auf und nennen unsere Verständnislücke Gott). Gott kann keine Antwort sein (aus den oben mehrfach genannten, vielen Gründen), Gott ist nicht nötig als Antwort und auch nicht nötig als Ausrede. Ein realitätsbezogenes, empirisches Weltbild hat keinen Bedarf für Gott. Da wird nichts "weg gedacht", das besteht einfach nicht der Bedarf ees sich hin zu denken. Genausowenig wie Wichtel, Weihnachtsmänner, Trolle... obwohl ich manchmal schon glaube das Trolle real sind........

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13The earth's  atmosphere   Empty Re: The earth's atmosphere Wed Jan 27, 2016 6:22 pm

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Oxygen Was Present from the Start


Free oxygen is death to life trying to evolve, but it was present early on, being formed naturally from atmospheric carbon dioxide.
What is life?  What is the meaning of life?  Astrobiologist Chris McKay says it’s a tricky question, but on Astrobiology Magazine, he offers a contrasting challenge: “in the search for life in our solar system what is needed more than a definition of life is a definition of death.”  And what does it mean to be dead?  “It means that the organism was once alive and is composed of organic molecules that are specific to life — molecules such as , , and proteins.”  Life, therefore, consists of many non-living parts, but just putting the parts together doesn’t make them alive.
Scientists at Davis didn’t say it directly, but origin of life research just got dealt a death blow.  A press release from Davis says that oxygen forms naturally from carbon dioxide:
About one-fifth of the Earth’s atmosphere is oxygen, pumped out by green plants as a result of photosynthesis and used by most living things on the planet to keep our metabolisms running. But before the first photosynthesizing organisms appeared about 2.4 billion years ago, the atmosphere likely contained mostly carbon dioxide, as is the case today on Mars and Venus.
Over the past 40 years, researchers have thought that there must have been a small amount of oxygen in the early atmosphere. Where did this abiotic (“non-life”) oxygen come from? Oxygen reacts quite aggressively with other compounds, so it would not persist for long without some continuous source.
That continuous source was ultraviolet light from the sun.  It’s just a simple one-step process to get oxygen out of the atmosphere from 2, the scientists found with lab simulations.  “According to one of the scientists who reviewed the paper for Science, Zhou’s work means that models of the evolution of planetary atmospheres will now have to be adjusted to take this into account.
This article was reproduced on ’s Astrobiology Magazine without any clarification of how models will have to be adjusted, or what it means for naturalistic origin-of-life hopes.  It ended, though, with this disclaimer: “Publication of press-releases or other out-sourced content does not signify endorsement or affiliation of any kind.”
Here’s the adjustment they will have to make: evolution is dead.  Oxygen is death to prebiotic chemistry.  It reacts with everything the origin-of-life scientists want to cook up.  It destroys the amino acids the Millerites make with sparks; that’s why Miller carefully excluded it from his spark chambers.  Creationists have argued this for years (see Creation.com, Answers in Genesis, ).  Their views have now been vindicated; John Long’s evolution parade will have to fold up shop, because his Darwin magic show has no power.
Evolutionists cannot get life to start if oxygen was around.  This is a make-or-break finding, and it just broke evolution.  Sorry, guys; game over.  Look for another explanation.  Creation, perhaps?


http://crev.info/2014/10/ool-oxygen/

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14The earth's  atmosphere   Empty Re: The earth's atmosphere Fri Jan 29, 2016 2:50 am

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The origin of life: a critique of current scientific models


In 1992 Han and Runnegar made a discovery which impinged on discussions of oxygen evolution during the Precambrian. To everyone’s surprise they reported the spiral algal fossil Grypania within banded iron formations (BIFs) in Michigan, USA. Algae require oxygen, so their existence at this juncture shows banded iron formations do not necessarily indicate global anoxic conditions.5
Indeed, as early as 1980 two reports appeared on the discovery of stromatolites in the 3.4–3.5 Ga Warrawoona Group sediments from the Pilbara Block, Australia.6,7 Similar remains were also discovered in Zimbabwe8 and South Africa.9
It is fair to conclude that the Earth’s early atmosphere before 3.5 Ga could have significant quantities of oxygen. This should discourage the sort of hypothesising on abiotic monomer and polymer syntheses so often assumed to have occurred in Archaean times. Robert Riding says that the Grypania discovery

“ … could spell the end of BIF-dominated models of oxygen build-up in the early atmosphere … The cat really will be put among the pigeons, however, if [further] fossil discoveries extend the eukaryote record back much beyond 2200 million years ago, into what is still widely perceived to have been an essentially anaerobic world.”10

Leslie Orgel wrote:
Recent investigations indicate the earth's atmosphere was never as reducing as Urey and Miller presumed. 2



1) http://creation.com/origin-of-life-critique
2) http://nideffer.net/proj/Hawking/early_proto/orgel.html

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Origin of Life: Earth's Early Atmosphere Wasn't Reducing 2

The standard assumption in origin of life research has been that the primordial earth had a reducing atmosphere, which favors prebiotic chemistry. Although more recent studies have suggested this assumption might not be true, a Nature study now directly shows that the earth did not have a reducing atmosphere up to 4.35 billion years ago1—even before the beginning of the late heavy bombardment and the first evidence for the origin of life. The new study also explains why there is no evidence for a prebiotic soup (non-biologic carbon deposits) in the earth's earliest rocks.

The oxidation state of Hadean magmas and implications for early Earth’s atmosphere 1

Magmatic outgassing of volatiles from Earth’s interior probably played a critical part in determining the composition of the earliest atmosphere, more than 4,000 million years (Myr) ago1. Given an elemental inventory of hydrogen, carbon, nitrogen, oxygen and sulphur, the identity of molecular species in gaseous volcanic emanations depends critically on the pressure (fugacity) of oxygen. Reduced melts having oxygen fugacities close to that defined by the iron–wüstite buffer would yield volatile species such as CH4, H2, H2S, NH3 and CO, whereas melts close to the fayalite–magnetite–quartz buffer would be similar to present-day conditions and would be dominated by H2O, CO2, SO2 and N2 (refs 1–4). Direct constraints on the oxidation state of terrestrial magmas before 3,850 Myr before present (that is, the Hadean eon) are tenuous because the rock record is sparse or absent. Samples from this earliest period of Earth’s history are limited to igneous detrital zircons that pre-date the known rock record, with ages approaching ~4,400 Myr (refs 5–8 ). Here we report a redox-sensitive calibration to determine the oxidation state of Hadean magmatic melts that is based on the incorporation of cerium into zircon crystals. We find that the melts have average oxygen fugacities that are consistent with an oxidation state defined by the fayalite–magnetite–quartz buffer, similar to present-day conditions. Moreover, selected Hadean zircons (having chemical characteristics consistent with crystallization specifically from mantle-derived melts) suggest oxygen fugacities similar to those of Archaean and present-day mantle-derived lavas2, 3, 4, 9, 10 as early as ~4,350 Myr before present. These results suggest that outgassing of Earth’s interior later than ~200 Myr into the history of Solar System formation would not have resulted in a reducing atmosphere.

1. http://www.nature.com/nature/journal/v480/n7375/full/nature10655.html
2. http://www.godandscience.org/evolution/earth_early_atmosphere.html#n01



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16The earth's  atmosphere   Empty Re: The earth's atmosphere Sun May 21, 2017 9:36 pm

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The Primitive Atmosphere

Thu, 26 Jan 2017 | Evolutionary Theory

ATMOSPHERE WITHOUT OXYGEN—Could a non-oxygen atmosphere ever have existed on Planet Earth? It surely seems like an impossibility, yet evolutionary theorists have decided that the primitive environment had to have a "reducing atmosphere," that is, one without any oxygen. Now, the theorists do not really want such a situation, but they know that it would be totally impossible for the chemical compounds needed for life to be produced outside in the open air. If oxygen was present, amino acids, etc., could not have been formed. So, in desperation, they have decided that at some earlier time in earth's history, there was no oxygen—anywhere in the world! And then later it somehow arrived on the planet!

"At that time, the 'free' production of organic matter by ultraviolet light was effectively turned off and a premium was placed on alternative energy utilization mechanisms. This was a major evolutionary crisis. I find it remarkable that any organism survived it."—*Carl Sagan, The Origins, p. 253.

But there is a special reason why they would prefer to avoid a reducing atmosphere: There is no evidence anywhere in nature that our planet ever had a non-oxygen atmosphere! And there is no theory that can explain how it could earlier have had a reducing (non-oxygen) atmosphere,—which later transformed itself into an oxidizing one! As *Urey himself admitted, a non-oxygen atmosphere is just an assumption—a flight of imagination— in an effort to accommodate the theory (*Harold Urey, "On the Early Chemical History of the Earth and the Origin of Life, " in Proceedings of the National Academy of Science, 38, 1952, p. 352).

*Stanley Miller was one of the pioneers in laboratory synthesis of non-living amino acids in bottles with a non-

oxygen (reducing) atmosphere. (He was afterward hailed by the press as having "created life. ") Miller later said the theory that the earth once had no oxygen is just "speculation" (*Stanley L. Miller, "Production of Some Organic Compounds under Possible Primitive Conditions, " in Journal of the American Chemical Society, 7, 1955, p. 2351).

A "reducing atmosphere" could have had methane, hydrogen, ammonia, and nitrogen. An oxidizing atmosphere, such as now exists, would have carbon dioxide, water, nitrogen, and oxygen.

(1) A reducing (non-oxygen) atmosphere never existed earlier on our planet; yet, without it, biological chemicals could not form. (2) If a reducing atmosphere had existed, so biological chemicals could form (and if they could somehow be injected with life), they would immediately die from lack of oxygen!
Here are some of the reasons against a reducing atmosphere:
(1) Oxidized iron. Early rocks contain partly or totally oxidized iron (ferric oxide). That proves that the atmosphere had oxygen back then.
(2) Water means oxygen. A reducing atmosphere could not have oxygen. But there is oxygen—lots of it— in water and in the atmosphere. According to *Brinkman, this fact alone disproves the origins of life by evolution (*R.T. Brinkman, "Dissociation of Water Vapor and Evolution of Oxygen in the Terrestrial Atmosphere, " Journal of Geophysical Research, 74, 1969, p. 5366). Are the evolutionists daring to tell us that, anciently, our planet had no water? No water above, on, or under the planet?
(3) No Life without it. How long would animals live without oxygen to breathe? How long would plants live without carbon dioxide? Without it, they could not make chlorophyll. When plants take in carbon dioxide, they give out oxygen. But a reducing atmosphere has neither oxygen nor carbon dioxide! Therefore no plants could either live or be available for food. In addition, plants need oxygen for cellular respiration.
(4) Deadly peroxides. A reduction atmosphere would form, through the photolysis of water, into peroxides, which are deadly to living creatures (* Abelson, "Some Aspects of Paleobiochemistry, "in Annals of the New York Academy of Science, 69, 1957, p. 275).
(5) No ozone layer. If there were no oxygen in the atmosphere, there would be no ozone either. Without the ozone layer, ultraviolet light would destroy whatever life was formed.
(6) Ultraviolet light. Ironically, it could do more damage in an atmosphere without oxygen. Just as oxygen in the air would destroy the chemicals of life, ultraviolet light beaming in through a sky unshielded by ozone would be deadly!
Recent studies of the ozone layer have revealed that, without it, most living organisms now on our planet would die within an hour, and many within a second or two!
(7) Not with or without. Evolutionists are locked into a situation here that they cannot escape from. Spontaneous generation could not occur with oxygen, and it could not occur without it!

FORMULA FOR THE PRIMITIVE ATMOSPHERE—Our present atmosphere (the air which we breathe) is composed of carbon dioxide (C02), nitrogen (N2), oxygen (02), and water (H20).

The generally postulated primitive atmosphere would have had to have been composed of almost totally different chemicals: methane (CH4), carbon monoxide (CO), ammonia (NH3), nitrogen (N2), hydrogen (H2), and water (H20).

INSTANT ATMOSPHERIC CHANGE—As you might imagine, all this bad news brought evolutionary origins to something of a crisis, especially a problem about the atmosphere.

So the intransigent evolutionists came up with the wild theory that at the very instant when life was cre ated on earth,—at that instant it just so happened that the entire world changed its atmosphere! It dramatically shifted suddenly from reducing to oxidizing!

But this possibility collapsed when a *University of Chicago study found that the plants could not suddenly have made all that oxygen,—and the oxygen had nowhere else to come from! If all the plants NOW on earth were suddenly formed on Day One on our planet, it would still take them 5000 years to produce as much oxygen as we now have!

However, the plants were not there at that time, and whatever plants might have been there would all have died soon after, since they themselves need oxygen for their own cellular respiration.

In order to avoid the problem of mass action degradation of amino acids formed in seawater, someone else suggested that the amino acids were made in dry clays and rocks. But in that environment, either the oxygen or ultraviolet light would immediately destroy those amino acids.

UNUSUAL CHEMICALS—Men began to beat their brains against the wall, trying to figure out a way for those amino acids to form by themselves in the primitive environment.

* Sidney Fox suggested that the amino acids were made on the edges of volcanoes, *Melvin Calvin decided that dicyanimide (a compound not naturally occurring in nature) did the job, and *Shramm declared that phosphorus pentoxide in a jar of ether did it! Another research worker came up with an even more deadly solution: hydrogen cyanide—as the environment in which all the amino acids made themselves.

But again tragedy struck: It was discovered that the volcanic heat would ruin the amino acids as soon as they were formed. Phosphorus pentoxide is a novel compound that could not possibly be found in earth's primitive atmosphere. The hydrogen cyanide would require an atmo sphere of ammonia, which geological evidence shows never existed in our atmosphere. Dicyanimide would not work, because the original mixture in which the first amino acids were made had to have a more alkaline pH.

On and on it goes, one conjecture after another; always searching for the magic mixture and fairyland environment needed to make life out of nothing.

"Every time I write a paper on the origin of life, I determine I will never write another one, because there is too much speculation running after too few facts."— *Francis Crick, Life Itself (1981), p. 153. [*Crick received a Nobel Prize for discovering the structure of DNA.]

https://www.wilmingtonfavs.com/evolutionary-theory/the-primitive-atmosphere.html



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The Atmosphere Between 4.4 and 4.0 Ga: An Outline 1

Mainstream science models predict that the terrestrial atmosphere mainly consisted of carbon dioxide (CO2), together with a still significant amount of water vapor (H2O), as well as with other components in lesser abundance – but not of lesser importance – such as molecular hydrogen (H2), molecular nitrogen (N2), and methane (CH4). How did this atmospheric composition emerge?

Carbon Dioxide Takes Control of the Climate
After the condensation of the oceans, CO2 became the principal component of the atmosphere, with a partial pressure that, depending on the estimations, ranges between 40 and 210 bars. This produced a significant greenhouse effect which resulted in a surface temperature of 200 to 250 °C. Under these conditions, siliceous rocks (basalts of the oceanic crust or granitoids of the continental crust) underwent leaching (at the bottom of the oceans and, where appropriate, through erosion of any emergent surface), resulting in the release of silica and bicarbonate. The overall outcome of these two reactions is that a molecule of atmospheric CO2 (or of CO2 dissolved in the ocean) was trapped in a mineral (carbonate). To prime this CO2 “pump”, all that was required was that liquid water should be available at the planet’s surface. However, a very significant reduction of the atmospheric partial pressure of CO2, required a sufficient cooling of the oceanic crust such that subduction was able to start, allowing the recycling of significant volumes of carbonate sedimentary rocks into the mantle, and consequently the long-term sequestration of the carbon that they contained. The Jack Hills zircons show us that fragments of continental crust, undoubtedly generated in a subduction geodynamic environment. From then on, the atmospheric CO2 partial pressure decreased, leading to a diminution of the greenhouse effect, such that the temperature at the surface of the Earth became compatible with life.  However, once the subduction process had become active, trapping of CO2 in carbonate sediments could have become so efficient that the average surface temperature of the Earth was capable of dropping below the fateful threshold of 0 °C, resulting in a global glaciation (the “Snowball Earth”). Given the low luminosity of the young Sun (about 70 per cent of its current value ), only an efficient greenhouse effect could then have prevented such a global glaciation. The most recent atmospheric models predict that the CO2 partial pressure, below which such an event could have occurred on Earth, would be between 0.2 and 1 bar. It must be noted that at present the total atmospheric pressure is 1 bar, of which only 3.5 × 10–4 bar is CO2. Nothing can rule out the fact that such glacial episodes may indeed have taken place.

It should, however, be noted that on a totally frozen Earth, trapping of CO2 by alteration of silicates becomes ineffective, because this gas continues to be emitted continuously through volcanic activity. This then induces an increase in CO2 atmospheric content and a correlated increase of the greenhouse effect, which enables the Earth to rapidly escape – on a geological time-scale – from the global glaciation. The CO2 pump responsible for the alteration of silicates could then restart, eventually leading to a new “Snowball Earth” episode, or in a less extreme fashion, to variation around a state where the two constraints remained in balance. We can, therefore, see how climate regulation through carbon dioxide and episodes of glaciation – partial or total – could come to arise on the Hadean Earth. Under such conditions, it is hard to see how temperate climatic conditions could have been maintained on the Earth’s surface. In this scenario, the temperatures hospitable to life could only have arisen very temporarily and episodically, either during the initial cooling corresponding to the period when the CO2 started to be trapped though silicate alteration or in the wake of reheating possibly induced by large-size meteoritic impacts. However, a frozen Earth is not an insurmountable obstacle to the emergence of life. Indeed, liquid water may circulate beneath an ice-cap, and this latter is even liable to melt at the surface when close to regions with a high geothermal flux. In addition, the possible presence, within the ice, of pockets of water laden with organic substances and remaining liquid at low temperature could equally have become a very propitious factor in the development of life.

But, in fact, the problem does not lie there. Rather, it arises from the fact that this vision of an extremely cold Earth at the end of the Hadean is in complete contradiction with the values found for palaeotemperatures of surface ocean water. These latter have been determined from oxygen- and silicon isotope measurements in sedimentary rocks dated from the very beginning of the Archaean, i.e., 3.8 Ga: these temperatures are, in fact, of about 70 °C, which, depending of the models used, corresponds to a greenhouse effect resulting in an atmospheric CO2 partial pressure of about 3 bars. We are forced, therefore, to recognize that several elements and clues are missing when studying such a distant period in the Earth’s history...

How can we explain this hiatus? A first hypothesis is that we can imagine that the CO2 trapping through silicate alteration at the bottom of the oceans could have been less effective than in the scenario just described above. A strong cooling leading to glaciation would then require large-scale alteration of emerged continents. A second hypothesis consists in assuming that the high temperatures that prevailed during the early Archaean resulted from the metabolism of methanogenic organisms capable of enriching the atmosphere in powerful greenhouse gas. As such, life would have already been present by 3.8 Ga and its action on the environment would have caused the first drastic alteration in the atmospheric composition. Another hypothesis might be the abiotic production of atmospheric methane. Nevertheless, both the early existence of methanogenic Archaea and the effects of high atmospheric methane content are the subject of debate. Undoubtedly, years of research will be required before being able to decide the situation in the Archaean is by no means simpler because once again we do not have any direct record of the atmospheric composition at that time. In the end, all that we can say about the composition of the atmosphere between 4.4 and 2.5 Ga solely rests on models that are liable to significantly evolve and change as our overall picture of the primitive Earth improves.

Evolution of the Atmosphere During the Hadean and Archean 2

Up to this point, I have made arguments for an early surface environment in which the vast majority of the carbon is in the form of organic compounds, distributed in several forms: floating as an immiscible layer of the ocean, dissolved in seawater, trapped as an organic component in ocean-bottom sediment, and in terrestrial ponds or along their shorelines, perhaps even coating some emergent dry land. I base these conclusions on an analysis of the processes that most likely gave rise to the earliest atmosphere and how that atmosphere would have responded to surface conditions of sunlight, electrical discharge, and various surface reactions. It is also strongly suggested by the apparent necessity of having organic-rich, and probably voluminous, reservoirs as a condition for the emergence of life from abiotic conditions. The modern atmosphere and the modern carbon reservoirs are dramatically different from the scene I have constructed. It is reasonable, and necessary, to ask how that early surface evolved into the present state. Fundamentally this is about oxidation. The presence of free oxygen in our atmosphere is vital, but actually a quantitatively small part of that problem. The enormous amount of oxidized carbon in carbonate rocks is many orders of magnitude greater than atmospheric oxygen, but if it started out as reduced (organic) carbon, virtually all of it must have been produced by oxidative processes. This chapter discusses the geochemical, and eventually biogeochemical, processing of the initially reduced carbon inventory to achieve this oxidation and ultimately the production of free oxygen in the atmosphere. It is obvious that oxidation of the surface carbon reservoir, in essence, involves hydrogen loss to space. Hydrogen production begins immediately by photochemical processing of the methane and ammonia that are generated and regenerated through hydrothermal release from organics in contact with the widespread volcano-hydrothermal systems on the early Earth. Hydrogen is also produced by the reaction of subducted organics with water during partial melting in the upper mantle. These systems must have been more extensive and/or more active than the modern ocean-ridge/subduction system in order to accommodate the higher heat production from radioactive decay and from residual impact heating. Radioactive decay alone implies at least a factor of four in heat release.

 Photolysis of methane and ammonia would produce hydrogen which is more stable in a reducing atmosphere than it would be in an atmosphere dominated by N2 and CO2. In addition, the methane and ammonia are themselves “vehicles” for moving hydrogen to higher levels in the atmosphere where hydrogen produced by photolysis can readily escape Earth’s gravity field. Hydrogen produced hydrothermally and magmatically and released into lower levels of the atmosphere can readily convect to the upper atmosphere for escape. Quantifying this process is rather difficult but hydrogen loss from the upper atmosphere must have been many orders of magnitude greater than the present rate (about 2 × 108 molecules/cm2-s (Walker 1977)) in order to account for the requisite surface oxidation. If we assume that all carbonate was produced by this hydrogen loss we can calculate a minimum rate necessary to reach the present ratio of carbonate to organic carbon for the entire carbon inventory by the end of the Archean. I choose that timing because that is roughly the point at which significant free atmospheric oxygen is thought to have become established. The calculation is simple, just provide enough hydrogen loss from water to give the oxygen (two for each carbon atom) to turn reduced carbon to carbon dioxide (or ultimately carbonate). It actually requires about twice this amount of hydrogen loss because you also have to account for the reductants, mostly hydrogen, attached


1. M. Gargaud · H. Martin · P. López-García T. Montmerle · R. Pascal Young Sun, Early Earth and the Origins of Life   page 74
2. Earth’s Early Atmosphere and Oceans, and the Origin of Life



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18The earth's  atmosphere   Empty Re: The earth's atmosphere Sun Jun 04, 2017 3:32 pm

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THE MYTH OF THE PRE-BIOTIC ATMOSPHERE 1

The Oxygen Problem

    The atmospheric conditions proposed by Oparin, Haldane and Urey were radically different from what presently exists. Because oxygen destroys the chemical building blocks of life, they speculated that the early earth had an oxygen-free atmosphere. However, in the last twenty years, evidence has surfaced that has convinced most atmospheric scientists that the early atmosphere contained abundant oxygen.

    In the 1970's Apollo 16 astronauts discovered that water is broken down into oxygen and hydrogen gas in the upper atmosphere when it is bombarded by ultraviolet radiation. This process, called photodissociation, is an efficient process which would have resulted in the production of large quantities of oxygen in a relatively short time. Studies by the astronauts revealed that this process is probably a major source of oxygen in our current atmosphere. 2 H2O + uv Radiation -- H2 (hydrogen gas) + O2 (oxygen gas)

    The assumption of an oxygen-free atmosphere has also been rejected on theoretical grounds. The ozone layer around planet earth consists of a thin but critical blanket of oxygen gas in the upper atmosphere. This layer of oxygen gas blocks deadly levels of ultraviolet radiation from the sun. Without oxygen in the early atmosphere, there could have been no ozone layer over that early earth. Without an ozone layer, all life on the surface of planet earth would face certain death from exposure to intense ultraviolet radiation. Furthermore, the chemical building blocks of proteins, RNA and DNA, would be quickly annihilated because ultraviolet radiation destroys their chemical bonds. It doesn't matter if these newly formed building blocks are in the atmosphere, on dry ground, or under water. It has been estimated that in order to form an effective ozone layer, the atmospheric oxygen content would need to be at least 10% of the amount in our current atmosphere. However, this same concentration of oxygen is also enough to quickly and effectively wipe out those same building blocks. Ultraviolet light breaks the chemical bonds of complex molecules such as amino acids and nucleotides, making them useless for the spontaneous generation of life.

    So we have a major dilemma. The products of the Miller-Urey experiments would be destroyed if oxygen was present, and they would be destroyed if it wasn't! This "catch 22" has been noted by evolutionist and molecular biologist Michael Denton:

    "What we have then is a sort of 'Catch 22' situation. If we have oxygen we have no organic compounds, but if we don't we have none either."

    Even if the building blocks of life could survive the effects of intense ultraviolet radiation and form life spontaneously, the survival of any subsequent life forms would be very doubtful in the presence of such heavy ultraviolet light. Ozone must be present to protect any surface life from the deadly effects of ultraviolet radiation from the sun.

    Finally, the assumption that there was no oxygen in the early atmosphere is not borne out by the geologic evidence. Geologists have discovered evidence of abundant oxygen content in the oldest known rocks on earth. Again, Michael Denton:

    "Ominously, for believers in the traditional organic soup scenario, there is no clear geochemical evidence to exclude the possibility that oxygen was present in the Earth's atmosphere soon after the formation of its crust."

    All of this evidence supports the fact that there was abundant oxygen on the early earth.

1. http://xwalk.ca/origin.html



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19The earth's  atmosphere   Empty Carbon dioxide Wed Jun 21, 2017 11:37 pm

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Effects of Changing the Carbon Cycle

It is significant that so much carbon dioxide stays in the atmosphere because CO2 is the most important gas for controlling Earth’s temperature. Carbon dioxide, methane, and halocarbons are greenhouse gases that absorb a wide range of energy—including infrared energy (heat) emitted by the Earth—and then re-emit it. The re-emitted energy travels out in all directions, but some returns to Earth, where it heats the surface. Without greenhouse gases, Earth would be a frozen -18 degrees Celsius (0 degrees Fahrenheit). With too many greenhouse gases, Earth would be like Venus, where the greenhouse atmosphere keeps temperatures around 400 degrees Celsius (750 Fahrenheit).

Because scientists know which wavelengths of energy each greenhouse gas absorbs, and the concentration of the gases in the atmosphere, they can calculate how much each gas contributes to warming the planet. Carbon dioxide causes about 20 percent of Earth’s greenhouse effect; water vapor accounts for about 50 percent, and clouds account for 25 percent. The rest is caused by small particles (aerosols) and minor greenhouse gases like methane. Water vapor concentrations in the air are controlled by Earth’s temperature. Warmer temperatures evaporate more water from the oceans, expand air masses, and lead to higher humidity. Cooling causes water vapor to condense and fall out as rain, sleet, or snow. Carbon dioxide, on the other hand, remains a gas at a wider range of atmospheric temperatures than water. Carbon dioxide molecules provide the initial greenhouse heating needed to maintain water vapor concentrations. When carbon dioxide concentrations drop, Earth cools, some water vapor falls out of the atmosphere, and the greenhouse warming caused by water vapor drops. Likewise, when carbon dioxide concentrations rise, air temperatures go up, and more water vapor evaporates into the atmosphere—which then amplifies greenhouse heating. So while carbon dioxide contributes less to the overall greenhouse effect than water vapor, scientists have found that carbon dioxide is the gas that sets the temperature. Carbon dioxide controls the amount of water vapor in the atmosphere and thus the size of the greenhouse effect. Rising carbon dioxide concentrations are already causing the planet to heat up. At the same time that greenhouse gases have been increasing, average global temperatures have risen 0.8 degrees Celsius (1.4 degrees Fahrenheit) since 1880.

This rise in temperature isn’t all the warming we will see based on current carbon dioxide concentrations. Greenhouse warming doesn’t happen right away because the ocean soaks up heat. This means that Earth’s temperature will increase at least another 0.6 degrees Celsius (1 degree Fahrenheit) because of carbon dioxide already in the atmosphere. The degree to which temperatures go up beyond that depends in part on how much more carbon humans release into the atmosphere in the future.

Ocean
About 30 percent of the carbon dioxide that people have put into the atmosphere has diffused into the ocean through the direct chemical exchange. Dissolving carbon dioxide in the ocean creates carbonic acid, which increases the acidity of the water. Or rather, a slightly alkaline ocean becomes a little less alkaline. Since 1750, the pH of the ocean’s surface has dropped by 0.1, a 30 percent change in acidity. Ocean acidification affects marine organisms in two ways. First, carbonic acid reacts with carbonate ions in the water to form bicarbonate. However, those same carbonate ions are what shell-building animals like coral need to create calcium carbonate shells. With less carbonate available, the animals need to expend more energy to build their shells. As a result, the shells end up being thinner and more fragile. Second, the more acidic water is, the better it dissolves calcium carbonate. In the long run, this reaction will allow the ocean to soak up excess carbon dioxide because more acidic water will dissolve more rock, release more carbonate ions, and increase the ocean’s capacity to absorb carbon dioxide. In the meantime, though, more acidic water will dissolve the carbonate shells of marine organisms, making them pitted and weak. Warmer oceans—a product of the greenhouse effect—could also decrease the abundance of phytoplankton, which grow better in cool, nutrient-rich waters. This could limit the ocean’s ability to take carbon from the atmosphere through the fast carbon cycle. On the other hand, carbon dioxide is essential for plant and phytoplankton growth. An increase in carbon dioxide could increase growth by fertilizing those few species of phytoplankton and ocean plants (like sea grasses) that take carbon dioxide directly from the water. However, most species are not helped by the increased availability of carbon dioxide.

Land
Plants on land have taken up approximately 25 percent of the carbon dioxide that humans have put into the atmosphere. The amount of carbon that plants take up varies greatly from year to year, but in general, the world’s plants have increased the amount of carbon dioxide they absorb since 1960. Only some of this increase occurred as a direct result of fossil fuel emissions. With more atmospheric carbon dioxide available to convert to plant matter in photosynthesis, plants were able to grow more. This increased growth is referred to as carbon fertilization. Models predict that plants might grow anywhere from 12 to 76 percent more if atmospheric carbon dioxide is doubled, as long as nothing else, like water shortages, limits their growth. However, scientists don’t know how much carbon dioxide is increasing plant growth in the real world, because plants need more than carbon dioxide to grow. Plants also need water, sunlight, and nutrients, especially nitrogen. If a plant doesn’t have one of these things, it won’t grow regardless of how abundant the other necessities are. There is a limit to how much carbon plants can take out of the atmosphere, and that limit varies from region to region. So far, it appears that carbon dioxide fertilization increases plant growth until the plant reaches a limit in the amount of water or nitrogen available. Some of the changes in carbon absorption are the result of land use decisions. Agriculture has become much more intensive, so we can grow more food on less land. In high and mid-latitudes, abandoned farmland is reverting to forest, and these forests store much more carbon, both in wood and soil, than crops would. In many places, we prevent plant carbon from entering the atmosphere by extinguishing wildfires. This allows woody material (which stores carbon) to build up. All of these land use decisions are helping plants absorb human-released carbon in the Northern Hemisphere.

In the tropics, however, forests are being removed, often through fire, and this releases carbon dioxide. As of 2008, deforestation accounted for about 12 percent of all human carbon dioxide emissions. The biggest changes in the land carbon cycle are likely to come because of climate change. Carbon dioxide increases temperatures, extending the growing season and increasing humidity. Both factors have led to some additional plant growth. However, warmer temperatures also stress plants. With a longer, warmer growing season, plants need more water to survive. Scientists are already seeing evidence that plants in the Northern Hemisphere slow their growth in the summer because of warm temperatures and water shortages. Dry, water-stressed plants are also more susceptible to fire and insects when growing seasons become longer. In the far north, where an increase in temperature has the greatest impact, the forests have already started to burn more, releasing carbon from the plants and the soil into the atmosphere. Tropical forests may also be extremely susceptible to drying. With less water, tropical trees slow their growth and take up less carbon, or die and release their stored carbon to the atmosphere. The warming caused by rising greenhouse gases may also “bake” the soil, accelerating the rate at which carbon seeps out in some places. This is of particular concern in the far north, where frozen soil—permafrost—is thawing. Permafrost contains rich deposits of carbon from plant matter that has accumulated for thousands of years because the cold slows decay. When the soil warms, the organic matter decays and carbon—in the form of methane and carbon dioxide—seeps into the atmosphere. Current research estimates that permafrost in the Northern Hemisphere holds 1,672 billion tons (Petagrams) of organic carbon. If just 10 percent of this permafrost were to thaw, it could release enough extra carbon dioxide to the atmosphere to raise temperatures an additional 0.7 degrees Celsius (1.3 degrees Fahrenheit) by 2100.


1. https://earthobservatory.nasa.gov/Features/CarbonCycle/page5.php

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Sunlight as an Energetic Driver in the Synthesis of Molecules Necessary for Life 1

The early atmosphere contained very little oxygen or other species that are generated by reactions with molecular oxygen, such as ozone. The exact composition of the atmosphere during the Hadean has been controversial, though most agree that it was not oxidizing. Yet, while many concur that it was likely reducing during the Hadean, some argue that the global atmosphere was neutral at the advent of life, perhaps with locally reducing
environments (e.g. near volcanoes). The dominant species in the atmosphere were most likely N2 and CO2. Some have considered that there might have been up to 100 bar of CO2 during this period, but it is more commonly assumed that the overall atmospheric pressure was close to the 1 bar of today. Additionally, constraints from paleosols39, 40 and banded iron formations suggest that upper limit to the mixing ratio of CO2 during the Archean was somewhere between 3 to 50 times the present atmospheric level. Using these constraints, the early Earth’s atmosphere has been modeled with mixing ratios of N2 and CO2 of roughly 0.9 and 0.1, respectively, with other minor trace gases included.

1. http://pubs.rsc.org.sci-hub.cc/en/content/articlelanding/2016/cp/c6cp00980h#!divAbstract

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21The earth's  atmosphere   Empty Re: The earth's atmosphere Tue Jun 27, 2017 9:19 pm

Otangelo


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Deine "Quelle" Zitiert da Literatur von 1971...

Das Buch von Koonin ist von 2011, und ist SEKULAR. Dh, kein Kreationistenbuch.....

Aber vielleicht koenntest du erklaeren, wie du dir folgendes vorstellst von einem rein technischen standpunkt aus :  Wie gezeigt, ist jedes der 20 Proteine und Proteinkomplexe unerlaesslich , und auch eine maximal zulaessliche mutationsrate. Wenn diese ueberschritten wird, ist DNA replikation nicht moeglich. Die Zelle stirbt. Wurden die 20 Proteine aus zufall genau spezifiziert, damit sie genau interagieren koennen, zusammenpassen, und der produktionablauf , wurde der durch zufall programmiert ? Wie kamen die Proteine in der richtigen sequenz zusammen ? Wie wurden sie zusammengeknuepft ohne katalisatoren ?

http://reasonandscience.heavenforum.org/t2024-the-rna-world-and-the-origins-of-life#3414

In order to copy RNA, fragments or monomers (individual building blocks) that have 5'-triphosphates must be ligated together. This is true for modern (protein-based) polymerases, and is also the most likely mechanism by which a ribozyme self-replicase in an RNA world might function. Yet no one has found a natural ribozyme that can perform this reaction.

Welches waren die chancen, dass alle richtigen materialien am richtigen Zeitpunkt am richtigen Ort vorhanden waren? Wie kam es, dass alle linkshaendigen Aminosäuren am Ort vorhanden waren, wenn natuerlich links und rechthaendige produziert werden im verhaeltnis 50%/50% ? Ausserdem: Wenn es Sauerstoff gab in der Atmosphaere, dann wuerde dieser die Aminosäuren zerstoeren. Gaebe es keinen, wuerden die UV Strahlen dies tun.....

http://reasonandscience.heavenforum.org/t1556-the-earth-s-atmosphere?highlight=oxygen

There is a problem if you consider the ozone (O3) layer which protects the earth from ultraviolet rays. Without this layer, organic molecules would be broken down and life would soon be eliminated. But if you have oxygen, it prevents life from starting. A "catch-22" situation (Denton 1985, 261-262):

  Atmosphere with oxygen => No amino acids => No life possible!
  Atmosphere without oxygen => No ozone => No life possible!

meinst Du nicht, da hat sich mittlerweile was getan? Zudem deine Quelle(n) ohnehin ziemlich zusammenhangslos zitieren, siehe das pubmed gelistete Meinungswerk zur RNA Welt bei der allein der Titel aber nicht der Inhalt die These stützte. Ich glaube der Hauptgrund warum wir hier streiten ist, das Du bei dem Jahrhundertedauernden "Rückzugsgefecht" einfach noch nicht auf dem neuesten Stand bist. Vor 200 Jahren war es "die Planeten drehen sich (um die Sonne), das hat Gott gemacht"... heute würde das niemand mehr sagen.

haha. Dann schau doch mal, was fuer antworten es da gibt auf diese Frage...... Was Newton geschrieben hat, gilt noch heute.

In the book, The Truth: God or evolution? Marshall and Sandra Hall describe an often quoted exchange between Newton and an atheist friend.

http://reasonandscience.heavenforum.org/t1939-isaac-newton?highlight=newton

“ Sir Isaac had an accomplished artisan fashion for him a small scale model of our solar system, which was to be put in a room in Newton's home when completed. The assignment was finished and installed on a large table. The workman had done a very commendable job, simulating not only the various sizes of the planets and their relative proximities, but also so constructing the model that everything rotated and orbited when a crank was turned. It was an interesting, even fascinating work, as you can imagine, particularly to anyone schooled in the sciences.
Newton's atheist-scientist friend came by for a visit. Seeing the model, he was naturally intrigued, and proceeded to examine it with undisguised admiration for the high quality of the workmanship. "My, what an exquisite thing this is!" he exclaimed. "Who made it?"
Paying little attention to him, Sir Isaac answered, "Nobody." Stopping his inspection, the visitor turned and said, "Evidently you did not understand my question. I asked who made this." Newton, enjoying himself immensely no doubt, replied in a still more serious tone, "Nobody. What you see just happened to assume the form it now has." "You must think I am a fool!" the visitor retorted heatedly, "Of course somebody made it, and he is a genius, and I would like to know who he is!" Newton then spoke to his friend in a polite yet firm way: "This thing is but a puny imitation of a much grander system whose laws you know, and I am not able to convince you that this mere toy is without a designer or maker; yet you profess to believe that the great original from which the design is taken has come into being without either designer or maker! Now tell me by what sort of reasoning do you reach such an incongruous conclusion?"

Vor 10 Jahren war es "sowas kompliziertes wie das Flagellum von Bakterien mit über 30 Einzelkomponenten die alleine keinen Sinn machen, das muß Gott gemacht haben"... das sagt heute auch keiner mehr, *jede* der Komponenten hat eine Einzelne Funktion und einige der Komponenten in Verbindung miteinander auch schon. Dann vor vielleicht 5 Jahren war es "Aber die DNA-Replikation..." blabla, gleiche Geschichte.  Die Dinge bei der die moderne Wissenschaft heute mit den Schultern zucken müßte und sagen würde: "Da haben wir noch keine Idee wie es funktioniert, meinetwegen nenne es für die nächsten 5 Jahre "Gott" bis wir es dann erklären können" sind ganz andere. Die gibt es, aber auch sich auf die zu stürzen ist ... dumm. Das haben z.B. auch die Theologen im Vatikan eingesehen und ein "god of the gaps" wird mit jedem Jahr kleiner, weniger, unwichtiger und die Argumente des Vorjahres lächerlicher.

Außerdem scheinst Du ein vollkommenes Unverständniss zu haben was eine Hypothese, was eine Theorie und was "blanker Schmarn" ist. Das schöne an einer Hypothese ist doch, dass ich sie überprüfen kann, ich widerlege oder bestätige sie. Wenn Sie nur in Teilen richtig war bessere ich nach und versuche mich wieder am bestätigen und widerlegen. So wird unser - schon von Natur aus nie perfekt sein könnendes - Verständnis der Vorgänge um uns herum immer präziser, besser, genauer. Das hat nichts mit "glauben" zu tun. Es ist nun mal die beste Erklärung die wir haben und wenn ich finde da stimmt was nicht formuliere ich eine neue und *überprüfe* diese, ist sie nicht besser, wird sie verworfen. Dein "blanker Schmarn" hingegen stellt Behauptungen in den Raum, fordert ein Ende des Nachdenkens, ist nicht nur nicht überprüfbar - und damit untauglich - sondern im Gegenteil, in diesen ganzen wirren Büchern alter Hirtenkulturen wird ja sogar gesagt, das man gegenteilige Beweise ignorieren soll! Hätten wir das getan, würden wir heute noch in Höhlen wohnen und nur Feuer haben wenn mal der Blitz eingeschlagen ist. Wir haben keine Smartphones oder Antibiotika, weil wir dafür gebetet haben, nicht weil sie irgend ein Schöpfer gemacht hat, sondern weil wir beim Erkennen des Zusammenhangs zwischen magnetfeld und elektrischem Strom nicht vor Ehrfurcht im Boden versunken sind, gesagt haben "das macht Gott" und aufgehört haben nachzudenken. Weil wir nicht gedacht haben "da hat der Schöpfer die Pilze aber lieber als die Bakterien und denen geholfen auf der verschimmelten Agagrplatte zu überleben", sondern weil wir dem auf den Grund gegangen sind und es verstanden haben.

Es wird nichts in ein "kein Gott notwendig" Gedankenbild gepreßt. Es wird ein Weltbild konstruiert und das stößt eben irgend wo an seine Grenzen. Das weckt dann unsere Neugier (oder wir haben Angst vor diesem Unwissen) und wir forschen, bis wir es verstehen (oder geben faul und verängstigt das Denken auf und nennen unsere Verständnislücke Gott). Gott kann keine Antwort sein (aus den oben mehrfach genannten, vielen Gründen), Gott ist nicht nötig als Antwort und auch nicht nötig als Ausrede. Ein realitätsbezogenes, empirisches Weltbild hat keinen Bedarf für Gott. Da wird nichts "weg gedacht", das besteht einfach nicht der Bedarf ees sich hin zu denken. Genausowenig wie Wichtel, Weihnachtsmänner, Trolle... obwohl ich manchmal schon glaube das Trolle real sind........

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The earth's  atmosphere   Atmosp10

http://www.nature.com.sci-hub.bz/nature/journal/v448/n7157/abs/nature06058.html?foxtrotcallback=true

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23The earth's  atmosphere   Empty Re: The earth's atmosphere Sun Aug 16, 2020 3:36 am

Otangelo


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The Perfect Atmosphere

Our atmosphere is also amazing and necessary. Among other things, it protects us from bombardments from space. It filters out the dangerous radiation from the Sun while allowing crucial light through. And it moderates Earth’s temperature. Our atmosphere is made up of just the right gases in just the right proportions to support life on Earth: 21% oxygen (O2), 78% nitrogen (N2), and a little argon (Ar), carbon dioxide (CO2), and water vapor (H2O).These gases are unreactive with each other—a crucial factor for long-term stability. We know that O2 is what we need to breathe to produce chemical energy in our bodies, so why are all those other gases necessary? An atmosphere with pure O2 would be disastrous for life on Earth. Plants, which require carbon dioxide, would be impossible. Wildfires would rage uncontrollably. And even oxygen-breathers, including animals, would suffer from excess oxygen. Nitrogen (N2) is a stable and rather unreactive gas that dilutes O2 to a life-friendly proportion. Earth’s atmosphere also contains traces of other gases, such as Ar, CO2 (from volcanoes), and CH4 (from cattle). Though they are only present in tiny amounts, they are necessary to life, forming the perfect greenhouse effect for life to stay warm and have access to enough energy. N2 is also essential for life on Earth and is perfectly suited to be the major constituent of our atmosphere, since it creates an atmosphere sufficiently thick to stabilize the planet’s liquid water and resist cosmic bombardment. N2 is a highly stable, chemically inert molecule made of two tightly, triply bound N≡N atoms, providing a perfect “solvent” for O2. The final mixture has the right air pressure and density to facilitate breathing and destroy most debris from space. N2 also provides nitrogen atoms for amino acids, the building blocks of proteins, and also for a wonderful array of other crucial nitrogen-containing biomolecules. N2 and O2 are therefore both essential for life on Earth and in roughly the specific ratio they are found in our atmosphere. Our N2-plus-O2 atmosphere is transparent to radio waves and visible light; hence we can appreciate that multitude of stars in the night sky while the atmosphere creates a blue sky during the daytime and a reddish sunset. This mixture of gases blocks the harmful radiation from the Sun even while letting us see so much of space, and send and receive radio waves. What an exquisite balance! But even with such a superb atmosphere, there is remains a problem to solve: Animals would quickly consume O2 and N2, converting O2 into CO2 and burning up Earth from an excessive greenhouse effect. Earth also needed processes to systematically fix N2 to the soil and oceans in a biochemically useful form. And indeed these processes are in place. A highly intricate network that includes lightning, microbes, plants, and animals creates the Earth’s O2 and N2 cycles. If proper O2 dilution and air pressure were the only major concerns, other gases could be selected, but the greenhouse effect of such gases would spoil the soup. Gases such as carbon dioxide (CO2), water vapor (H2O), methane (CH4), and ozone (O3), which are common in the atmosphere of other planets, could work as O2 solvents, but high concentrations of them would trap too much heat. Note another balance of Earth’s atmosphere. If Earth had no atmosphere at all, like Mercury, too much heat would leak into space during the night, freezing any life. Venus has the opposite problem. It isn’t as close to the Sun as its neighbor Mercury, but it is the hottest planet in our solar system because its atmosphere is almost exclusively CO2. This causes an extreme greenhouse effect, resulting in an average temperature of 864oF. So, Mercury’s atmosphere—too little. Venus’s atmosphere— too much. Earth’s—just right.

Ozone
The ozone layer displays an exquisite interplay of carefully crafted solutions. The Sun emits about 90% of its radiation in the visible and infrared (IR) range, perfect for life and photosynthesis. But the other 10% of sunlight is composed of different subsets of ultraviolet (UV) radiation, some of which are harmful and some of which is beneficial to life. For example, a little of UV-B is beneficial since it is required to produce bone-strengthening vitamin D, while some birds, insects, and mammals can see UV-A and use it to hunt. UV rays are also used to treat some skin conditions, such as psoriasis, vitiligo, localized scleroderma, and atopic dermatitis. But other portions of UV light are harmful. The atmosphere is perfectly equipped to solve this “devil/angel” dilemma, blocking the great majority of the harmful stuff and letting the good stuff through. What is known as the ozone layer plays a crucial role here. This atmospheric layer occupies the lower swath of the stratosphere, a portion stretching from nine to twenty-two miles above the Earth’s surface. It isn’t pure ozone, but it’s richer in ozone (O3) than are other parts of the atmosphere, containing a few parts per million of this essential triatomic molecule. The UV light emitted by the Sun is mainly composed of three subtypes: UV-A, UV-B, and UV-C, as well as a little UV-E. The ozone layer absorbs 97–99% of UV-B light, which would be potentially damaging to life in higher doses but provides a net benefit at lower doses. At the same time, it is mostly transparent to UV-A, the lifefriendliest of the ultraviolet lights. But what is really amazing about the O3 layer is that it works in perfect synchrony with N2 and O2, forming an O2 + O ⇌ O3 perfectly balanced equilibrium mediated by both UV-C and UV-E radiation. The O3 layer also seems to contain exactly the concentration at exactly the right altitude to block bad UV-C and excess UV-B radiation while letting UV-A and a useful amount of UV-B pass through. O3 also occurs in a layer close to the Earth’s surface, but as the U.S. Environmental Protection Agency explains, we create that ozone through industrial “chemical reactions of oxides of nitrogen (NOx) with volatile organic compounds (VOC) in the presence of sunlight,” leading to urban smog. The main sources of NOx and VOC are emissions from electrical utilities and industrial facilities, vehicle exhaust, gasoline vapors, and chemical solvents. O3 is harmful to our lungs and damages crops, trees, and vegetation in general.13 The problem would be much worse if not for the fact that O3 is a rather reactive molecule in the lower atmosphere, preventing it from accumulating to levels that would prove far more dangerous. And also fortunately, it is long-lived in the diluted (and colder) stratosphere where the O3 layer resides. The naturally formed O3, nine-plus miles above us, protects rather than harms us, thanks to its precise positioning. Ozone is created there when the most harmful and energetic portion of the UV-C light strikes O2. It is also amazing to discover that UV-C carries all the energy required to split the tightly covalently bonded O=O molecule into two O atoms. This highly reactive atomic oxygen then combines with molecular O2 to yield O3. This means that O2 chemically blocks the harmful radiation (UV-C) while at the same time creating beneficial O3 via a very reactive oxygen atom. This forms the protective O3 layer that filters excess harmful UV-B. But remember that O3 is by itself harmful to life, so it’s a good thing these reactions occur high in the sky. All this intricate cascade of reactions induced by radiation appears to have required careful planning to get everything right—gas densities, air pressures, temperatures, and reactivity—to limit this biologically harmful, pungent, and heavier-than-air O3 molecule to the right altitude and the right amount in our atmosphere. Let me explain in more detail how the whole process works and preserves life on Earth. O2 very much needs O3 as its wingman. O2 blocks most UV-C but it lets most of the UV-B through—far too much for life on the ground. UV-B escapes from the first O2 defender but is caught by the second, O3. When UV-B reaches O3 in the ozone layer, it is mostly absorbed, splitting O3 back into O2 and O. Hence, the excess of UV-B radiation is eliminated while at the same time turning O3 into O2, feeding the O2 + O ⇌ O3 equilibrium that is known as the ozone-oxygen cycle. To review, this time with numbers: Most harmful UV-C is first blocked by O2—specifically, the portion with wavelength of 100–200 nanometers. Any UV-C left over from O2 is blocked by the O3 layer (the UV-C with a wavelength of 200–280 nm), so the UV-C doesn’t reach the ground. The shorter portion of the UV-C band is then used to break O2 to O, forming O3, which blocks most of the sunburn-causing UV-B (the UV-B of 280–315 nanometers in wavelength). The friendly UV-A (315–400 nm) is nearly transparent to both O2 and O3, and much of this less harmful, mostly beneficial light reaches the ground. Atmospheric N2 is also part of the intricate blocking-filtering cycle, since N2 blocks the most harmful UV-E (of wavelength 10–100 nanometers). And remember, while the ozone layer does filter most of the UVB, a beneficial portion of its longest wavelengths is transparent to O3, reaching the surface, which our bodies use to produce vitamin D. Thus, an intricate interplay of different UV-absorbing and UVreacting proprieties of three gases (O2, O3, and N2) in our atmosphere protects life. If the O3 (plus O2 plus N2) layer were not there, overexposure to UV radiations would severely threaten life under the sun. The productivity of crops would be significantly reduced, and humans would experience suppressed immune systems, blindness, and a pandemic of skin cancer.14

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24The earth's  atmosphere   Empty Re: The earth's atmosphere Sat Jan 30, 2021 2:41 pm

Otangelo


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https://www.grisda.org/origins-02059#_edn8
Any photosynthesizing organism, by definition, would be exposed to light radiation and doubtless would be destroyed by the lethal short-wavelength ultraviolet rays.

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25The earth's  atmosphere   Empty Re: The earth's atmosphere Thu Feb 18, 2021 12:46 pm

Otangelo


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In 2011, Dustin Trail and colleagues at Rensselaer Polytechnic Institute studied the oxidation state of cerium found in zircons that are thought to be as old as the Earth itself, even predating the known rock record. They concluded that the oxidation state of the cerium was much higher than expected, suggesting that prebiotic synthesis should start with an entirely different set of gases: CO2, H2O, N2, and SO2. According to author Bruce Watson, “We can now say with some certainty that many scientists studying the origins of life on Earth simply picked the wrong atmosphere”. Here, the subjective statement “some certainty” is an optimistic way to convey a lack of real confidence in the atmospheric gasses. Prebiotic synthesis experiments based on the more neutral atmosphere that Trail and colleagues suggested produce less diversity of amino acids and a lower yield than the reducing atmosphere that Miller used. Others have attempted to sidestep the uncertainty over atmospheric conditions by focusing on aquatic conditions for prebiotic chemistry, but this too is mired in debate. The extreme temperature and acidity of “black smokers” and “white smokers,” two types of hydrothermal vents on the ocean floor, have been proposed as sites for prebiotic chemistry. Nick Lane, a biochemist at University College London, has argued that a very different, nonsmoking alkaline hydrothermal vent is the right environment for prebiotic chemistry. With all of the debate over appropriate prebiotic conditions on Earth, some find the possibility of prebiotic chemistry in outer space to be more attractive. Indeed, some building blocks of life have been found in meteorites, and Saturn’s moon Enceladus appears to have produced “complex macromolecular organic material with molecular masses above 200 atomic mass units”. Thus, we have some evidence that at least some amino acids can be produced naturally in trace amounts, along with a large majority of interfering, unwanted products. However, we also have many hypothesized and debated conditions for prebiotic synthesis of amino acids, with very little confidence in the actual conditions that supposedly generated the first amino acids.





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