Freethought & Rationalism Archive

Bumble Bee Tuna · 03-05-2003, 07:41 AM

So how does science reconcile the seemingly contradictory views that the Universe did not begin to exist and the second law of thermodynamics? It seems that the 2LoT suggests that the Universe did begin to exist at some point in time and has slowly been incresaing in entropy since then. So what does science say about this?

*I am not a theist trying to prove anything, I'm just asking for information*

-B

Wyz_sub10 · 03-05-2003, 07:53 AM

I think the scientific consensus is that theuniverse did 'begin'.

The 2nd Law only applies to the universe - not to what existed prior to the universe.

In other words, after the universe came into existence it operated in a way that can be described in terms of physics. But before that, physical laws as we know them did not apply.

It's a little like asking how could you have been born because before your birth your heart didn't beat and your brain didn't function? Obviously, those things didn't apply until after your birth.

Undercurrent · 03-05-2003, 08:20 AM

As per Wyz, the universe very likely did begin to exist at some point. Some creationists see this as a big coup for creationism, (which also says the universe began to exist at some point, but contradicts the Big Bang in most other aspects.)

But, even if the universe had existed forever, there would be no conflict with the second law of thermodynamics. There are man functions (e.g. x -> exp(x) ) that are always increasing, as the entropy function would have to be, but are bounded below. In short, "entropy increasing" does not imply "universe existed for finite amount of time".

Theophage · 03-05-2003, 08:27 AM

Another thing to keep in mind is the expansion of the universe.

Your question implies the more specific question "So why aren't we at maximum entropy yet?" This would also seem to apply even to a very old universe (13 billion years is pretty old to me :^) as well as to an infinite one.

The answer is, of course, that an expanding universe generates more "room" for entropy to increase, so as long as it continues to do so (and it doesn't look like its ever going to stop) we won't have to worry about hitting the maximum entropy wall.

In an interview on the Positive Atheism site, physicist Victor Stenger gives the following analogy for this:

Quote:

An example I like to give on this, is, suppose that you have a very small yard, and every day you take your rubbish and you dump the rubbish into the yard. Eventually it's going to cover up those petunias that you plotted over there your garden, and your yard is going to become very disordered. How can you, then, get some more petunias growing? Well, what you can do is buy the land around your yard. Then you have more space and you can plant some petunias. As time goes on, of course, you keep dumping the rubbish and it fill up the space, you've got to keep buying more and more land. But, in principle, you can do it that way; you can always have some space left over. As long as the Universe continues to expand, in other words, there's always room for more order to form.

Jesse · 03-05-2003, 09:27 AM

Stenger's comment seems to suggest that at the beginning, the universe might have started out with the maximum entropy possible for its size, but from what I've read the consensus is that it actually would have had to have started in a state of very low entropy (although this is not certain because there is no general definition of gravitational entropy in general relativity).

03-05-2003, 07:41 AM	#1
Bumble Bee Tuna Veteran Member Join Date: Sep 2002 Location: Middletown, CT Posts: 7,333	THe 2LoT So how does science reconcile the seemingly contradictory views that the Universe did not begin to exist and the second law of thermodynamics? It seems that the 2LoT suggests that the Universe did begin to exist at some point in time and has slowly been incresaing in entropy since then. So what does science say about this? I am not a theist trying to prove anything, I'm just asking for information -B

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search

03-05-2003, 07:53 AM	#2
Wyz_sub10 Veteran Member Join Date: Aug 2002 Location: In the land of two boys and no sleep. Posts: 9,890	I think the scientific consensus is that theuniverse did 'begin'. The 2nd Law only applies to the universe - not to what existed prior to the universe. In other words, after the universe came into existence it operated in a way that can be described in terms of physics. But before that, physical laws as we know them did not apply. It's a little like asking how could you have been born because before your birth your heart didn't beat and your brain didn't function? Obviously, those things didn't apply until after your birth.

03-05-2003, 08:20 AM	#3
Undercurrent Veteran Member Join Date: Jan 2001 Location: Santa Fe, NM Posts: 2,362	As per Wyz, the universe very likely did begin to exist at some point. Some creationists see this as a big coup for creationism, (which also says the universe began to exist at some point, but contradicts the Big Bang in most other aspects.) But, even if the universe had existed forever, there would be no conflict with the second law of thermodynamics. There are man functions (e.g. x -> exp(x) ) that are always increasing, as the entropy function would have to be, but are bounded below. In short, "entropy increasing" does not imply "universe existed for finite amount of time".

03-05-2003, 09:27 AM	#5
Jesse Moderator - Science Discussions Join Date: Feb 2001 Location: Providence, RI, USA Posts: 9,908	Stenger's comment seems to suggest that at the beginning, the universe might have started out with the maximum entropy possible for its size, but from what I've read the consensus is that it actually would have had to have started in a state of very low entropy (although this is not certain because there is no general definition of gravitational entropy in general relativity).

Freethought & Rationalism Archive

The archives are read only.