[Dark Tofu]

I was just thinking over entropy and the need for a finite universe, when I came about this line of thinking. How is this explained by modern science? (Not currently an argument against atheism, I just don't understand the modern understanding.)

Entropy is the measure of how dispersed energy is in a system. The more dispersed the energy is, the more difficult it is to draw energy out of the system from within the system. Thus, it is said that entropy is also a measure of the available energy in a system. The second law of thermodynamics says that entropy of the universe tends to increase as time progresses. Another way of stating the second law is that available energy in the universe tends to increase as time progresses. If we follow time backwards, then, the available energy in the universe will tend to increase until we reach the point where all of the energy in the universe is available. At this point, there is no more energy to be made available, or the energy is in a state of complete instability, lacking any equilibrium. There can be no more backward progression in entropy, no more decrease in equilibrium.
We understand that in order for entropy to be increased in any system, that there must be an equal or larger decrease in entropy elsewhere in the universe, else the second law be violated. We understand the universe to be all things that exist. The question then becomes, how did the instability of the universe come to be like it was when there was no longer anywhere that could have lent its stability in order to allow for the universe's instability?

[nate95366]

Originally Posted by Dark Tofu

Another way of stating the second law is that available energy in the universe tends to increase as time progresses.

I think you mean the opposite of this in regards to time.

Originally Posted by Dark Tofu

We understand that in order for entropy to be increased in any system, that there must be an equal or larger decrease in entropy elsewhere in the universe, else the second law be violated.

I think it's the other way around, actually. Any decrease in the entropy of a system is accompanied by an equal or greater increase in the entropy of the universe overall.

Originally Posted by Dark Tofu

We understand the universe to be all things that exist. The question then becomes, how did the instability of the universe come to be like it was when there was no longer anywhere that could have lent its stability in order to allow for the universe's instability?

I think the current scientific theory that attempts to deal with this is called the "Big Bang Theory." It isn't "good" enough to answer questions of the ultimate origin of all this matter and energy (with its intrinsic entropy) around us, but it seems to be a reasonable explaination to me.

Nate

[JerryLove]

The question then becomes, how did the instability of the universe come to be like it was when there was no longer anywhere that could have lent its stability in order to allow for the universe's instability?

You lost me.

The net direction of entropy is to increase towards maximum entropy.

Go forward in time, and there will be the same or more entropy in the universe.
Go backward in time and there will be the same or less entropy.

Local entropy can work in reverse of this, but overal entropy (universal entropy) moves from less to more forward through time from the big bang to the imaginable future.

So what's your question?

[Dark Tofu]

Originally Posted by nate95366

I think you mean the opposite of this in regards to time.

I think it's the other way around, actually. Any decrease in the entropy of a system is accompanied by an equal or greater increase in the entropy of the universe overall.

Ha. Ya, that's what I meant. I said those parts backwards.

I think the current scientific theory that attempts to deal with this is called the "Big Bang Theory." It isn't "good" enough to answer questions of the ultimate origin of all this matter and energy (with its intrinsic entropy) around us, but it seems to be a reasonable explaination to me.

Nate

I understand the Big Band Theory. It does not explain how the entropy of the universe got to the stage that it started at. The entropy must have started very small, if not at a stage of zero. This would mean a complete instability of energy, even though the universe as a whole will never decrease in entropy. So how did the entropy get to the stage of instability that it started in, if things always wish to become more equal?

Originally Posted by JerryLove

You lost me.

The net direction of entropy is to increase towards maximum entropy.

Go forward in time, and there will be the same or more entropy in the universe.
Go backward in time and there will be the same or less entropy.

Local entropy can work in reverse of this, but overal entropy (universal entropy) moves from less to more forward through time from the big bang to the imaginable future.

So what's your question?

I think I restated the question better earlier in this post, but here's another shot at it.

How did the universe acheive a state of extremely low entropy (or zero entropy) in the beginning, if things always push to become more entropic?
Where did that decreased entropy come from?

[JerryLove]

Originally Posted by Dark Tofu

How did the universe acheive a state of extremely low entropy (or zero entropy) in the beginning, if things always push to become more entropic?
Where did that decreased entropy come from?

So if I understand your question: At some point in the past, the universe was at it's minimum entropy. You believe that there was a time before that point at which the universe had more entropy.

I'm not sure that your premise is correct, nor even logically possible (time is a dimension of the universe), but if I assume both I would say: I don't know. We have no information at all about the universe "prior" to the big bang.

Jerry

[shakeybill]

Originally Posted by Dark Tofu

How did the universe acheive a state of extremely low entropy (or zero entropy) in the beginning, if things always push to become more entropic?
Where did that decreased entropy come from?

As a Christian I believe the big bang with the initial low universal entropy was God's creation event described in Genesis 1:1. If you want a naturalistic explanation we don't have one.

Speaking as a mechanical engineer your (and Jerry's) discussion on this subject is spot on. Both my Thermo prof at UMass Lowell and the writer of my Thermo textbook shared the theistic implecations of the big bang and the universal increase in entropy.

Regards, Bill