The concept of singularity refers to a point of infinite density and temperature, typically associated with the Big Bang theory, which is the leading scientific explanation for the origin of the universe.
Stephen Hawking:
Strictly speaking, according to Einstein's Theory of Relativity, a singularity does not contain anything that is actually infinite, only things that MOVE MATHEMATICALLY TOWARDS infinity. A singularity's mass is, therefore, finite, the 'infinity' refers only to the maths. Can we have an infinite universe for example? The answer is no, the universe is finite. in
'A Brief History of Time' (1989 page 44) describes the universe as being "finite but unbounded".
Theories propose that the singularity was not the absolute beginning of the universe, but rather a transition point from a pre-existing state or a result of a previous universe collapsing or "bouncing." One challenge for the bouncing universe hypothesis is the issue of the second law of thermodynamics, which is a fundamental principle of physics that states that the total entropy (a measure of disorder) of a closed system tends to increase over time. If the universe were to undergo cycles of contraction and expansion indefinitely, it would need to violate the second law of thermodynamics during the contraction phase, as entropy would need to decrease to enable a "bounce" and initiate a new expansion phase.
Guth, A.H. and M. Sher:
The ability of the universe to oscillate is dependent upon a certain critical mass. This critical mass is required to slow the expansion of the universe and force a contraction. If this total mass is not present, which seems likely, then the universe will continue to expand into eternity. Even if there were enough mass to cause the universe, the result of that collapse would be a "Big Crunch" as opposed to another Big Bang. The reason that the universe would not "bounce" if it were to contract is that the universe is extremely inefficient (entropic). In fact, the universe is so inefficient that the bounce resulting from the collapse of the universe would be only 0.00000001% of the original Big Bang (see table above). Such a small "bounce" would result in an almost immediate re-collapse of the universe into one giant black hole for the rest of eternity.
1983. The impossibility of a bouncing universe. Nature 302: 505-506.
Stephen Hawking:
Strictly speaking, according to Einstein's Theory of Relativity, a singularity does not contain anything that is actually infinite, only things that MOVE MATHEMATICALLY TOWARDS infinity. A singularity's mass is, therefore, finite, the 'infinity' refers only to the maths. Can we have an infinite universe for example? The answer is no, the universe is finite. in
'A Brief History of Time' (1989 page 44) describes the universe as being "finite but unbounded".
Theories propose that the singularity was not the absolute beginning of the universe, but rather a transition point from a pre-existing state or a result of a previous universe collapsing or "bouncing." One challenge for the bouncing universe hypothesis is the issue of the second law of thermodynamics, which is a fundamental principle of physics that states that the total entropy (a measure of disorder) of a closed system tends to increase over time. If the universe were to undergo cycles of contraction and expansion indefinitely, it would need to violate the second law of thermodynamics during the contraction phase, as entropy would need to decrease to enable a "bounce" and initiate a new expansion phase.
Guth, A.H. and M. Sher:
The ability of the universe to oscillate is dependent upon a certain critical mass. This critical mass is required to slow the expansion of the universe and force a contraction. If this total mass is not present, which seems likely, then the universe will continue to expand into eternity. Even if there were enough mass to cause the universe, the result of that collapse would be a "Big Crunch" as opposed to another Big Bang. The reason that the universe would not "bounce" if it were to contract is that the universe is extremely inefficient (entropic). In fact, the universe is so inefficient that the bounce resulting from the collapse of the universe would be only 0.00000001% of the original Big Bang (see table above). Such a small "bounce" would result in an almost immediate re-collapse of the universe into one giant black hole for the rest of eternity.
1983. The impossibility of a bouncing universe. Nature 302: 505-506.
