Monistic Idealism
https://reasonandscience.catsboard.com/t2773-monistic-idealism
According to a common viewpoint, the primary entities in such a theory are taken to be the quantum fields, the particles themselves arising merely as 'field excitations'." Pay particular attention to Roger Penrose's last sentence which suggests that the "primary entities" are the fields — not the particles. If a particle of matter meets its antimatter equivalent then both particles disappear in a flash of energy (potentially quite destructive energy). The reverse process is also true: if enough energy can be confined to a small space then a particle can be created together with its antimatter equivalent (a process known as pair production). It is possible to make particles! This means that the number of particles in the universe is not a fixed number. This development is described by Roger Penrose in his book The Road to Reality: "The key property of an antiparticle is that the particle and antiparticle can come together and annihilate one another, their combined mass being converted into energy, in accordance with Einstein's E=mc2. Conversely, if sufficient energy is introduced into a system then there arises the strong possibility that this energy might serve to create some particle together with its antiparticle. Thus, our relativistic theory certainly cannot just be a theory of single particles, nor of any fixed number of particles whatever.
Everything is fields
As an example, a beam of light is composed of many billions of photons in the same state (photons are bosons). It is therefore possible to use the creation operator to create as many bosons in the same state as you wish. It is then said that those particles are indistinguishable. However, two fermions cannot exist in the same state due to the Pauli exclusion principle. So we cannot use the creation operator to create two fermions (for example, two electrons) in the same state. For this reason, it is said that those particles are distinguishable.
What is implied by the fact that all particles are identical in quantum field theory QFT? It has been suggested that it implies something extraordinary: there are not multiple particles, there is only the one field. As an example, all electrons are identical because they are not actually separate objects, they are merely different parts of a single electron field which covers the entire universe. This principle is described well by Leon van Dommelen: "There is a field of electrons, there is a field of protons (or quarks, actually), there is a field of photons, etc.
I am not an openly declared idealist, but i think the idea is interesting, worth of further investigation.
Monistic idealism considers consciousness to be the primary reality. The world of matter is considered to be determined by consciousness as is the subtle world of mental phenomena, such as thought. Besides the material and the subtle (which together form the immanent reality or the world of appearance), idealism posits a transcendent archetypal or ideal realm as the “source” of the lower immanent worlds of appearance of the material and the subtle. However, monistic idealism is fundamentally a monistic philosophy; any subdivisions such as the three orders above are in consciousness – thus, ultimately, consciousness is the only reality. 1
Quantum mechanics gives us a revolutionary view of reality, a view radically different from the deterministic, causal, continuous, and objective view of the world of classical mechanics. The philosophy of monistic idealism can come to the rescue of quantum physicists in their 90-year-old struggle to find a paradox-free interpretation of quantum mechanics.
The wave and particle aspects of a quantum object are complementary; yet for a single quantum object, the wave nature never manifests; whenever we look we always “see” a quantum object localized, as a particle.
The Dirac revolution
Dirac's great moment of inspiration came in 1928 when he was staring into the fireplace at Cambridge University. Dirac realised how it was possible to combine quantum mechanics with special relativity. The result was that Dirac derived his famous equation for an electron which is known as the Dirac equation. The Dirac equation made some extraordinary predictions. It predicted the spin of an electron, which was quickly realised to be a perfect match with experiment. But, most extraordinary of all, the Dirac equation predicted new types of particles which we now know as antimatter. It is now known that all particles have an antimatter equivalent. It was the discovery of antimatter which was to have such a revolutionary effect in quantum mechanics. If a particle of matter meets its antimatter equivalent then both particles disappear in a flash of energy (potentially quite destructive energy).
The reverse process is also true: if enough energy can be confined to a small space then a particle can be created together with its antimatter equivalent (a process known as pair production). It is possible to make particles! This means that the number of particles in the universe is not a fixed number. This development is described by Roger Penrose in his book The Road to Reality: "The key property of an antiparticle is that the particle and antiparticle can come together and annihilate one another, their combined mass being converted into energy, in accordance with Einstein's E=mc2. Conversely, if sufficient energy is introduced into a system then there arises the strong possibility that this energy might serve to create some particle together with its antiparticle. Thus, our relativistic theory certainly cannot just be a theory of single particles, nor of any fixed number of particles whatever.
Indeed, according to a common viewpoint, the primary entities in such a theory are taken to be the quantum fields, the particles themselves arising merely as 'field excitations'." Pay particular attention to Roger Penrose's last sentence which suggests that the "primary entities" are the fields — not the particles.
Leon van Dommelen says in his excellent web-based book Quantum Mechanics for Engineers:
"The quantum formalism in this book cannot deal with particles that appear out of nothing or disappear. A modified formulation called quantum field theory is needed."
Quantum Field Theory is the mathematical framework used to understand fundamental particles, like electrons. It tells us that these particles come from “fields.” A field is something that fills all of space and can vibrate in certain characteristic ways; and those field vibrations can propagate along like waves in a pond. In quantum theory waves and particles are two different ways of looking at the same thing, so electrons can be thought of as particles or ripples in the “electron field” that fills all of space. This helps explain why all electrons are exactly alike. A good analogy is this: whether I stick my finger into a pond over here or over there, the same kind of ripples will spread out in either case, because the water of the pond is the same everywhere. Similarly, all electron waves (which is to say, all electrons) are the same because the electron field that fills space is the same everywhere.
One must ask why the electron field is the same everywhere in space. That it is so is a very powerful fact which has to be assumed in constructing our theories of physics in order to agree with what we see in the real world. It is not an absolute logical or mathematical necessity by any means. The fact that the electron field has uniform properties throughout all of space is itself a statement that the electron field possesses a very large degree of symmetry, in fact a much greater degree of symmetry than is enjoyed by any specific set of electron particles or carbon atoms.
If we look at the world around us, we see only hints of order here and there peeking out from amidst a great deal of apparent irregularity and haphazardness. But science has given us new eyes that allow us to see down to the deeper roots of the world’s structure, and there all we see is order and symmetry of pristine mathematical purity.
Quantum theory showed that particles and forces were really two manifestations of the same “quantum fields.” Einstein showed that space and time were inseparable parts of a four-dimensional “space-time.” In the late 1960s and early 1970s, electromagnetism and the weak interactions were discovered to be parts of a unified “electroweak” force. And there is a great deal of circumstantial evidence that the electroweak force and the strong force are parts of one grand unified force, and even that all forces including gravity are unified.
Everything is fields
All particles can be categorised into one of two groups: they are either bosons or fermions. Bosons like being in the same state. As an example, a beam of light is composed of many billions of photons in the same state (photons are
bosons). It is therefore possible to use the creation operator to create as many bosons in the same state as you wish. It is then said that those particles are indistinguishable. However, two fermions cannot exist in the same state due to the Pauli exclusion principle. So we cannot use the creation operator to create two fermions (for example, two electrons) in the same state. For this reason, it is said that those particles are distinguishable.
What is implied by the fact that all particles are identical in quantum field theory QFT? It has been suggested that it implies something extraordinary: there are not multiple particles, there is only the one field. As an example, all electrons are identical because they are not actually separate objects, they are merely different parts of a single electron field which covers the entire universe. This principle is described well by Leon van Dommelen: "There is a field of electrons, there is a field of protons (or quarks, actually), there is a field of photons, etc.
Some physicists feel that is a strong point in favor of believing that quantum field theory is the way Nature really works. In the classical formulation of quantum mechanics, the (anti)symmetrization requirements under particle
exchange are an additional ingredient, added to explain the data. In quantum field theory, it comes naturally: particles that are distinguishable simply cannot be described by the formalism." This principle is also described on the Wikipedia page for quantum field theory, under the section "Physical meaning of particle indistinguishability".
Again, note that the crucial factor in QFT is that all particles (of the same type) are indistinguishable: "The second quantization procedure relies crucially on the particles being identical. From the point of view of quantum field theory, particles are identical if and only if they are excitations of the same underlying quantum field. Thus, the question 'why are all electrons identical?' arises from mistakenly regarding individual electrons as fundamental objects, when in fact it is only the electron field that is fundamental."
So it is now believed that we live in a universe in which everything that exists is a field. Every particle is just a part of a single field for that particle type. Every field stretches the length and breadth of the universe.
How does the single field sometimes appear like particles? It is because particles emerge in the field like waves in the ocean — they are not actually separate from the field, just like a wave is not separate from the ocean. These particles emerge when enough energy is transferred to a small region of the field, like a rock dropped into the ocean. Particles are often referred to as "excitations" of the field. As an example, this is how the Higgs boson was
generated from the Higgs field by the high-energy collider at the LHC.
Sean Carroll has an excellent talk on YouTube filmed at Fermilab called Particles, Fields, and the Future of Physics in which he emphasises this idea that everything is a field: "That particle stuff is overrated. Actually, everything is made of fields. You don't need to separately talk about matter made of particles and forces made of fields. All you need are fields." Here is a link to Sean Carroll's talk:
http://tinyurl.com/seancarrolltalk
Here is another quote from Sean Carroll's talk. This is certainly a guiding principle behind the writing of this book: "To working physicists, quantum field theory is the most important thing we know. But when we talk about physics to non-physicists, when we popularise it, we never mention quantum field theory. We talk about particle physics, we talk about relativity, we talk about quantum mechanics. Heck we even talk about string theory and the multiverse and the anthropic principle. But we think quantum field theory is too much to bother about." Another populariser of the "Everything is Fields" philosophy is the retired physicist Rodney Brooks. Brooks is no longer working in academia, but in the 1950s he was taught by Julian Schwinger who was one of the founders of QFT, and Brooks has made it his retirement project to raise awareness and understanding of QFT in the general public. He is very much an evangelist of the idea that fields are everything, and everything is fields: "No particles, only fields". Brooks has created a video in which he explains his views on QFT:
http://tinyurl.com/rodneybrooks
Brooks also appears to be on a mission to increase awareness of his tutor, the Nobel prize-winning Julian Schwinger. Schwinger's field-based approach to QFT lost in the popularity stakes to the particle-based approach to QFT which was easier to understand and calculate and was popularised by the more charismatic Richard Feynman. An understanding of QFT can explain effects which seem so puzzling in quantum mechanics: "In quantum field theory, the uncertainty principle becomes trivial. A field is spread-out. An electron is a particle which might be here, it might be there, might have this momentum, might have that momentum — that doesn't make sense. Feynman is correct. But a field that is spread out is not just 'could be here' or 'could be there' — it's here, and here, and here. So that problem, for example, is resolved." I would agree with Brooks's explanation of the uncertainty principle: uncertainty about position makes a lot more sense when you consider fields rather than point-particles. Also, quantum entanglement — a connection between particles over great distances — also makes more sense when we consider fields extended through space rather than point-particles. And at the 28-minute mark of his aforementioned video, Sean Carroll also explains how a field (or wave) approach can provide a simple explanation for the interactions between particles.
The Higgs mechanism
One of the fields which crosses the entire universe is called the Higgs field. The behaviour and structure of the Higgs field is notably different from the other fields. The Higgs field is responsible for giving mass to elementary particles The particle associated with the Higgs field is the famous Higgs boson. As a fermion travels through the Higgs field (which permeates the entire universe) it interacts with a sea of Higgs bosons. The result is that the particle slows down as if it is being pushed through a vat of sticky molasses (another common analogy is of a popular person trying to cross a room in a crowded party). As mass is defined as "resistance to acceleration", we interpret this slowing as the particle gaining mass. To understand how the Higgs field gives mass to bosons, let us first consider the difference between particles which have mass (massive particles) and particles which do not have mass (massless particles). The theory of special relativity states that if we try to accelerate an object up to the speed of light, the mass of that object will progressively increase. At the speed of light, the mass of the object would become infinite. In other words, it is not possible for an object with mass to move at the speed of light. This is a principle which applies to all massive particles such as electrons: electrons have to move at less than the speed of light.
However, a photon is an example of a massless particle. And if a particle has no mass, then it has no mass to increase as the speed of the particle approaches the speed of light. It is therefore possible
for a massless particle to move at the speed of light. After all, a photon is a particle of light, so it obviously has to move at the speed of light. Put simply, all massless particles move at the speed of light, and all massive particles have to move at less than the speed of light. This principle has implications for the spin of massive and massless particles. If we consider a particle in three-dimensional space, it is clear that there are three axes about which it can spin (the zaxis is coming out of the page):
Each of these spin axes is called a degree of freedom, with each degree of freedom representing an independent way in which the particle can move.
The Higgs boson — which was detected for the first time by the LHC in 2012 — introduces an additional fine-tuning problem. The problem is associated with the measured mass of the Higgs boson. The value of the Higgs mass cannot be calculated — it has to be measured experimentally. The LHC discovered the Higgs has a mass of approximately 125 GeV. Intuitively, though, particle physicists would have expected the Higgs mass to take a "natural" value, which turns out to be vastly heavier. A natural mass would be one in which all the "arbitrary dials" were turned to 1.0. In which case, the mass would have to be calculated only from fundamental constants. The three truly fundamental constants are the speed of light, c, the gravitational constant, G, and the Planck constant, h. These three constants can be combined in only one way to produce a quantity which has the units of mass.
Why the Higgs mass appears to be surprisingly light arises when we consider the effects of virtual particles temporarily popping into existence. The Higgs is responsible for giving mass to particles, so, conversely, the Higgs can interact with any particle that has mass. A Higgs boson can momentarily convert into a top quark/anti-top quark pair, before converting back to a Higgs boson. A top quark has been deliberately chosen for this example as it is the heaviest elementary particle (i.e., the one with the most mass). The weight of the top quark adds to the Higgs mass. Plus, we have to include the effects of all massive particles in our calculations (because the Higgs interacts with all massive particles). The end result is that all these quantum contributions once again push the expected weight of the Higgs up towards the vastly larger Planck mass.
So here we have an apparently huge gap between the expected value of the Higgs mass and the measured value: the Higgs is ten million billion times lighter than we would expect, or sixteen orders of magnitude. This huge gap in the mass values represents a hierarchy, and the problem of why the Higgs is so light is called the hierarchy problem. The hierarchy problem is considered to be one of the greatest unsolved problems in physics.
The hierarchy problem introduces another fine-tuning problem. If the Higgs mass was lighter, then atoms could not form and life could not exist. But if the Higgs was heavier — and particles were therefore as heavy as the Planck mass — then all particles would turn into black holes (too much mass squeezed into a microscopic volume). Hence, the Higgs mass value appears fine-tuned for the existence of life.
There is a popular hypothesis in physics called supersymmetry which has been around for forty years which has been touted as a potential solution to the apparent fine-tuning of the Higgs mass. Supersymmetry requires the existence of a whole suite of additional undetected particles called superpartners, each superpartner particle being matched to an existing known particle. According to supersymmetry, the superpartner of a boson is a fermion, and vice versa. The precise symmetry means that the huge quantum contributions from the known virtual particles would be cancelled by the contributions from the superpartner particles. With the huge contributions eliminated, a light Higgs is left. However, no superpartner particles have been discovered at the LHC, and supersymmetry appears to be in trouble. This is a big deal. Many theorists have spent decades of their lives working on supersymmetry. Also, if supersymmetry crashes and burns, then so does string theory which depends on supersymmetry. This has clearly become a high-stakes game. The failure of the LHC to discover new particles leading to the potential demise of supersymmetry — and the dearth of any replacement explanations — has been variously called the "nightmare scenario", a "crisis in physics", or even "the end of science". Perhaps a new approach is needed …
1. https://janszafranski.wordpress.com/2015/08/05/the-idealistic-interpretation-of-quantum-mechanics/
https://reasonandscience.catsboard.com/t2773-monistic-idealism
According to a common viewpoint, the primary entities in such a theory are taken to be the quantum fields, the particles themselves arising merely as 'field excitations'." Pay particular attention to Roger Penrose's last sentence which suggests that the "primary entities" are the fields — not the particles. If a particle of matter meets its antimatter equivalent then both particles disappear in a flash of energy (potentially quite destructive energy). The reverse process is also true: if enough energy can be confined to a small space then a particle can be created together with its antimatter equivalent (a process known as pair production). It is possible to make particles! This means that the number of particles in the universe is not a fixed number. This development is described by Roger Penrose in his book The Road to Reality: "The key property of an antiparticle is that the particle and antiparticle can come together and annihilate one another, their combined mass being converted into energy, in accordance with Einstein's E=mc2. Conversely, if sufficient energy is introduced into a system then there arises the strong possibility that this energy might serve to create some particle together with its antiparticle. Thus, our relativistic theory certainly cannot just be a theory of single particles, nor of any fixed number of particles whatever.
Everything is fields
As an example, a beam of light is composed of many billions of photons in the same state (photons are bosons). It is therefore possible to use the creation operator to create as many bosons in the same state as you wish. It is then said that those particles are indistinguishable. However, two fermions cannot exist in the same state due to the Pauli exclusion principle. So we cannot use the creation operator to create two fermions (for example, two electrons) in the same state. For this reason, it is said that those particles are distinguishable.
What is implied by the fact that all particles are identical in quantum field theory QFT? It has been suggested that it implies something extraordinary: there are not multiple particles, there is only the one field. As an example, all electrons are identical because they are not actually separate objects, they are merely different parts of a single electron field which covers the entire universe. This principle is described well by Leon van Dommelen: "There is a field of electrons, there is a field of protons (or quarks, actually), there is a field of photons, etc.
I am not an openly declared idealist, but i think the idea is interesting, worth of further investigation.
Monistic idealism considers consciousness to be the primary reality. The world of matter is considered to be determined by consciousness as is the subtle world of mental phenomena, such as thought. Besides the material and the subtle (which together form the immanent reality or the world of appearance), idealism posits a transcendent archetypal or ideal realm as the “source” of the lower immanent worlds of appearance of the material and the subtle. However, monistic idealism is fundamentally a monistic philosophy; any subdivisions such as the three orders above are in consciousness – thus, ultimately, consciousness is the only reality. 1
Quantum mechanics gives us a revolutionary view of reality, a view radically different from the deterministic, causal, continuous, and objective view of the world of classical mechanics. The philosophy of monistic idealism can come to the rescue of quantum physicists in their 90-year-old struggle to find a paradox-free interpretation of quantum mechanics.
The wave and particle aspects of a quantum object are complementary; yet for a single quantum object, the wave nature never manifests; whenever we look we always “see” a quantum object localized, as a particle.
The Dirac revolution
Dirac's great moment of inspiration came in 1928 when he was staring into the fireplace at Cambridge University. Dirac realised how it was possible to combine quantum mechanics with special relativity. The result was that Dirac derived his famous equation for an electron which is known as the Dirac equation. The Dirac equation made some extraordinary predictions. It predicted the spin of an electron, which was quickly realised to be a perfect match with experiment. But, most extraordinary of all, the Dirac equation predicted new types of particles which we now know as antimatter. It is now known that all particles have an antimatter equivalent. It was the discovery of antimatter which was to have such a revolutionary effect in quantum mechanics. If a particle of matter meets its antimatter equivalent then both particles disappear in a flash of energy (potentially quite destructive energy).
The reverse process is also true: if enough energy can be confined to a small space then a particle can be created together with its antimatter equivalent (a process known as pair production). It is possible to make particles! This means that the number of particles in the universe is not a fixed number. This development is described by Roger Penrose in his book The Road to Reality: "The key property of an antiparticle is that the particle and antiparticle can come together and annihilate one another, their combined mass being converted into energy, in accordance with Einstein's E=mc2. Conversely, if sufficient energy is introduced into a system then there arises the strong possibility that this energy might serve to create some particle together with its antiparticle. Thus, our relativistic theory certainly cannot just be a theory of single particles, nor of any fixed number of particles whatever.
Indeed, according to a common viewpoint, the primary entities in such a theory are taken to be the quantum fields, the particles themselves arising merely as 'field excitations'." Pay particular attention to Roger Penrose's last sentence which suggests that the "primary entities" are the fields — not the particles.
Leon van Dommelen says in his excellent web-based book Quantum Mechanics for Engineers:
"The quantum formalism in this book cannot deal with particles that appear out of nothing or disappear. A modified formulation called quantum field theory is needed."
Quantum Field Theory is the mathematical framework used to understand fundamental particles, like electrons. It tells us that these particles come from “fields.” A field is something that fills all of space and can vibrate in certain characteristic ways; and those field vibrations can propagate along like waves in a pond. In quantum theory waves and particles are two different ways of looking at the same thing, so electrons can be thought of as particles or ripples in the “electron field” that fills all of space. This helps explain why all electrons are exactly alike. A good analogy is this: whether I stick my finger into a pond over here or over there, the same kind of ripples will spread out in either case, because the water of the pond is the same everywhere. Similarly, all electron waves (which is to say, all electrons) are the same because the electron field that fills space is the same everywhere.
One must ask why the electron field is the same everywhere in space. That it is so is a very powerful fact which has to be assumed in constructing our theories of physics in order to agree with what we see in the real world. It is not an absolute logical or mathematical necessity by any means. The fact that the electron field has uniform properties throughout all of space is itself a statement that the electron field possesses a very large degree of symmetry, in fact a much greater degree of symmetry than is enjoyed by any specific set of electron particles or carbon atoms.
If we look at the world around us, we see only hints of order here and there peeking out from amidst a great deal of apparent irregularity and haphazardness. But science has given us new eyes that allow us to see down to the deeper roots of the world’s structure, and there all we see is order and symmetry of pristine mathematical purity.
Quantum theory showed that particles and forces were really two manifestations of the same “quantum fields.” Einstein showed that space and time were inseparable parts of a four-dimensional “space-time.” In the late 1960s and early 1970s, electromagnetism and the weak interactions were discovered to be parts of a unified “electroweak” force. And there is a great deal of circumstantial evidence that the electroweak force and the strong force are parts of one grand unified force, and even that all forces including gravity are unified.
Everything is fields
All particles can be categorised into one of two groups: they are either bosons or fermions. Bosons like being in the same state. As an example, a beam of light is composed of many billions of photons in the same state (photons are
bosons). It is therefore possible to use the creation operator to create as many bosons in the same state as you wish. It is then said that those particles are indistinguishable. However, two fermions cannot exist in the same state due to the Pauli exclusion principle. So we cannot use the creation operator to create two fermions (for example, two electrons) in the same state. For this reason, it is said that those particles are distinguishable.
What is implied by the fact that all particles are identical in quantum field theory QFT? It has been suggested that it implies something extraordinary: there are not multiple particles, there is only the one field. As an example, all electrons are identical because they are not actually separate objects, they are merely different parts of a single electron field which covers the entire universe. This principle is described well by Leon van Dommelen: "There is a field of electrons, there is a field of protons (or quarks, actually), there is a field of photons, etc.
Some physicists feel that is a strong point in favor of believing that quantum field theory is the way Nature really works. In the classical formulation of quantum mechanics, the (anti)symmetrization requirements under particle
exchange are an additional ingredient, added to explain the data. In quantum field theory, it comes naturally: particles that are distinguishable simply cannot be described by the formalism." This principle is also described on the Wikipedia page for quantum field theory, under the section "Physical meaning of particle indistinguishability".
Again, note that the crucial factor in QFT is that all particles (of the same type) are indistinguishable: "The second quantization procedure relies crucially on the particles being identical. From the point of view of quantum field theory, particles are identical if and only if they are excitations of the same underlying quantum field. Thus, the question 'why are all electrons identical?' arises from mistakenly regarding individual electrons as fundamental objects, when in fact it is only the electron field that is fundamental."
So it is now believed that we live in a universe in which everything that exists is a field. Every particle is just a part of a single field for that particle type. Every field stretches the length and breadth of the universe.
How does the single field sometimes appear like particles? It is because particles emerge in the field like waves in the ocean — they are not actually separate from the field, just like a wave is not separate from the ocean. These particles emerge when enough energy is transferred to a small region of the field, like a rock dropped into the ocean. Particles are often referred to as "excitations" of the field. As an example, this is how the Higgs boson was
generated from the Higgs field by the high-energy collider at the LHC.
Sean Carroll has an excellent talk on YouTube filmed at Fermilab called Particles, Fields, and the Future of Physics in which he emphasises this idea that everything is a field: "That particle stuff is overrated. Actually, everything is made of fields. You don't need to separately talk about matter made of particles and forces made of fields. All you need are fields." Here is a link to Sean Carroll's talk:
http://tinyurl.com/seancarrolltalk
Here is another quote from Sean Carroll's talk. This is certainly a guiding principle behind the writing of this book: "To working physicists, quantum field theory is the most important thing we know. But when we talk about physics to non-physicists, when we popularise it, we never mention quantum field theory. We talk about particle physics, we talk about relativity, we talk about quantum mechanics. Heck we even talk about string theory and the multiverse and the anthropic principle. But we think quantum field theory is too much to bother about." Another populariser of the "Everything is Fields" philosophy is the retired physicist Rodney Brooks. Brooks is no longer working in academia, but in the 1950s he was taught by Julian Schwinger who was one of the founders of QFT, and Brooks has made it his retirement project to raise awareness and understanding of QFT in the general public. He is very much an evangelist of the idea that fields are everything, and everything is fields: "No particles, only fields". Brooks has created a video in which he explains his views on QFT:
http://tinyurl.com/rodneybrooks
Brooks also appears to be on a mission to increase awareness of his tutor, the Nobel prize-winning Julian Schwinger. Schwinger's field-based approach to QFT lost in the popularity stakes to the particle-based approach to QFT which was easier to understand and calculate and was popularised by the more charismatic Richard Feynman. An understanding of QFT can explain effects which seem so puzzling in quantum mechanics: "In quantum field theory, the uncertainty principle becomes trivial. A field is spread-out. An electron is a particle which might be here, it might be there, might have this momentum, might have that momentum — that doesn't make sense. Feynman is correct. But a field that is spread out is not just 'could be here' or 'could be there' — it's here, and here, and here. So that problem, for example, is resolved." I would agree with Brooks's explanation of the uncertainty principle: uncertainty about position makes a lot more sense when you consider fields rather than point-particles. Also, quantum entanglement — a connection between particles over great distances — also makes more sense when we consider fields extended through space rather than point-particles. And at the 28-minute mark of his aforementioned video, Sean Carroll also explains how a field (or wave) approach can provide a simple explanation for the interactions between particles.
The Higgs mechanism
One of the fields which crosses the entire universe is called the Higgs field. The behaviour and structure of the Higgs field is notably different from the other fields. The Higgs field is responsible for giving mass to elementary particles The particle associated with the Higgs field is the famous Higgs boson. As a fermion travels through the Higgs field (which permeates the entire universe) it interacts with a sea of Higgs bosons. The result is that the particle slows down as if it is being pushed through a vat of sticky molasses (another common analogy is of a popular person trying to cross a room in a crowded party). As mass is defined as "resistance to acceleration", we interpret this slowing as the particle gaining mass. To understand how the Higgs field gives mass to bosons, let us first consider the difference between particles which have mass (massive particles) and particles which do not have mass (massless particles). The theory of special relativity states that if we try to accelerate an object up to the speed of light, the mass of that object will progressively increase. At the speed of light, the mass of the object would become infinite. In other words, it is not possible for an object with mass to move at the speed of light. This is a principle which applies to all massive particles such as electrons: electrons have to move at less than the speed of light.
However, a photon is an example of a massless particle. And if a particle has no mass, then it has no mass to increase as the speed of the particle approaches the speed of light. It is therefore possible
for a massless particle to move at the speed of light. After all, a photon is a particle of light, so it obviously has to move at the speed of light. Put simply, all massless particles move at the speed of light, and all massive particles have to move at less than the speed of light. This principle has implications for the spin of massive and massless particles. If we consider a particle in three-dimensional space, it is clear that there are three axes about which it can spin (the zaxis is coming out of the page):
Each of these spin axes is called a degree of freedom, with each degree of freedom representing an independent way in which the particle can move.
The Higgs boson — which was detected for the first time by the LHC in 2012 — introduces an additional fine-tuning problem. The problem is associated with the measured mass of the Higgs boson. The value of the Higgs mass cannot be calculated — it has to be measured experimentally. The LHC discovered the Higgs has a mass of approximately 125 GeV. Intuitively, though, particle physicists would have expected the Higgs mass to take a "natural" value, which turns out to be vastly heavier. A natural mass would be one in which all the "arbitrary dials" were turned to 1.0. In which case, the mass would have to be calculated only from fundamental constants. The three truly fundamental constants are the speed of light, c, the gravitational constant, G, and the Planck constant, h. These three constants can be combined in only one way to produce a quantity which has the units of mass.
Why the Higgs mass appears to be surprisingly light arises when we consider the effects of virtual particles temporarily popping into existence. The Higgs is responsible for giving mass to particles, so, conversely, the Higgs can interact with any particle that has mass. A Higgs boson can momentarily convert into a top quark/anti-top quark pair, before converting back to a Higgs boson. A top quark has been deliberately chosen for this example as it is the heaviest elementary particle (i.e., the one with the most mass). The weight of the top quark adds to the Higgs mass. Plus, we have to include the effects of all massive particles in our calculations (because the Higgs interacts with all massive particles). The end result is that all these quantum contributions once again push the expected weight of the Higgs up towards the vastly larger Planck mass.
So here we have an apparently huge gap between the expected value of the Higgs mass and the measured value: the Higgs is ten million billion times lighter than we would expect, or sixteen orders of magnitude. This huge gap in the mass values represents a hierarchy, and the problem of why the Higgs is so light is called the hierarchy problem. The hierarchy problem is considered to be one of the greatest unsolved problems in physics.
The hierarchy problem introduces another fine-tuning problem. If the Higgs mass was lighter, then atoms could not form and life could not exist. But if the Higgs was heavier — and particles were therefore as heavy as the Planck mass — then all particles would turn into black holes (too much mass squeezed into a microscopic volume). Hence, the Higgs mass value appears fine-tuned for the existence of life.
There is a popular hypothesis in physics called supersymmetry which has been around for forty years which has been touted as a potential solution to the apparent fine-tuning of the Higgs mass. Supersymmetry requires the existence of a whole suite of additional undetected particles called superpartners, each superpartner particle being matched to an existing known particle. According to supersymmetry, the superpartner of a boson is a fermion, and vice versa. The precise symmetry means that the huge quantum contributions from the known virtual particles would be cancelled by the contributions from the superpartner particles. With the huge contributions eliminated, a light Higgs is left. However, no superpartner particles have been discovered at the LHC, and supersymmetry appears to be in trouble. This is a big deal. Many theorists have spent decades of their lives working on supersymmetry. Also, if supersymmetry crashes and burns, then so does string theory which depends on supersymmetry. This has clearly become a high-stakes game. The failure of the LHC to discover new particles leading to the potential demise of supersymmetry — and the dearth of any replacement explanations — has been variously called the "nightmare scenario", a "crisis in physics", or even "the end of science". Perhaps a new approach is needed …
1. https://janszafranski.wordpress.com/2015/08/05/the-idealistic-interpretation-of-quantum-mechanics/
