Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Titanscape on 08/09/2011 16:36:27
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Hi science community, I wanted to ask if people thought it possible, that entropy changed or changes over time?
Was entropy that same ten thousand years ago, a million years ago, twelve billion years ago? Is it the same in other parts of the cosmos?
Being open minded myself with recollection of the experiments to test space for drag.
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Probability insists that entropy in a closed system can spontaneously decrease if one waits long enough (likely a really long time).
I do also wonder what the entropy of the Universe was like a moment after the Big Bang, when the Universe was, say, the size of an apple. It seems like it should have been in a nearly uniform state since large scale structures like stars, galaxies and planets wouldn't have been present.
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The chances are that entropy is always increasing in the cosmos. That's what entropy does. Even if there were some process going on to negate entropy in the short term. In the long term entropy will rule. Entropy is one of the main arrows of time.
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I'm guessing that the OP is asking about the whether the uniformly observed, and therefore apparently, universal constant of the rate of entropy has not always been as it is observed now.
- So a change in the rate of the system's disorder (2nd derivative of disorder?).
Perhaps related, there is evidence to support the universe having an early period of incredibly rapid expansion that might be argued to be also a period where the rate of entropy was much different to today - As MikeS says this has a potential role to play in the concept of the universes 'arrow of time'.
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When the Universe was very young hot and dense, it was too hot for matter to form. Entropy was very low. As it inflated and cooled much of the energy was converted into mass (essentially, hydrogen and helium). Entropy increased. As stars formed and started converting their mass into energy, it might have been expected that entropy would decrease. However, this energy production was (is) being balanced by the Universe expanding which is increasing entropy. Black holes consume both matter and energy and contribute to the overall increase in entropy.
Gravity is probably the Universes main source of entropy.
See http://www.thenakedscientists.com/forum/index.php?topic=40766.msg366116#msg366116
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Do you think it is possible that entropy such as on earth three billion years ago was so different, that it caused a self replicating cell to "fall" into place?