Thermodynamics and the Big Bang

[St.Michael]

I’ve heard a Creationist use this twice in an argument this week.

"The big bang violates the 2nd law of thermodynamic because something can’t come from nothing"!

As far as I’m aware the 2nd Law has nothing to do with something coming from nothing.

I think the guy must have read it on a creationist website or book and seems to think it is the ultimate way of proving creationism.

Can anyone shed some light on the subject?

 

[Piggy]

Here's a nice summary:

Re the 2nd law:

In an isolated system (one which exchanges neither matter nor energy with its surroundings) the available energy will decrease (or at best remain the same) with every real process that occurs. The energy... is no longer available to do useful work. The measure of the lost available energy is called entropy, or “disorder.” .... An implication of the second law is the “entropy principle” in which there is a general tendency for entropy to increase.

Re its application in creationism:

Another creationist argument involves what happens if we take the first and second laws to be valid throughout the entire existence of the universe, claiming that this implies a finite age for the universe. To give an example of such an argument, I’ll use one that Henry Morris makes in What is Creation Science? Keeping in mind that the first law says that the quantity of energy is constant, if we extrapolate into the past there would be a point where the total energy equals the amount of available energy [2]. Time can go back no further than this and so the universe must have a beginning. Another point that Morris makes [3] is that since the available energy is constantly decreasing, there will be a point in time where all the energy becomes unavailable to do further work, and hence the universe will be “dead.” Since the universe is not dead, it cannot be infinitely old [4]. The first law, recall, says that mass-energy cannot be created or destroyed. Consequently, the universe could not have created itself.[5] Thus, some agency outside the natural universe created it. Because anything outside the natural universe is by definition supernatural, creationists claim that it must have been a supernatural agency that created the universe.

 

[Big Al]

It is generally accepted that the primordial atom was in a state of minimal entropy; the Big Bang can certainly be regarded as a massive increase in entropy.

 

[Wavicle]

Physics really isn't my field, but isn't this one of those "can't determine what caused the big bang without knowing the state of the system before the big bang, but none of that information exists" types of questions? I thought we had to just accept that there was a sudden massive release of energy because all the evidence points to it having occurred. Whether the cause was nothing, God, or collision of two professional wrestlers in another universe; we just don't know, and such knowledge is probably unknowable within our universe.

 

[Dr Adequate]

I’ve heard a Creationist use this twice in an argument this week.

"The big bang violates the 2nd law of thermodynamic because something can’t come from nothing"!

He means the first law. They also have an argument from the second law, but that isn't it.

Answers:

(1) Show me where an actual physicist says that the Big Bang is "something coming from nothing". Or show it me in the equations. Yes, I know that that's what all the creationist websites say the Big Bang is. Show me a physicist saying it.

(2) We all learnt in high school that energy is conserved. So don't you think that actual scientists know this too? Don't you suppose they take this law of nature into account? Or do you suppose that a bunch of Nobel Prize winning physicists have overlooked a principle of physics so basic and simple that I've known it since I was fourteen?

 

[joobz]

(2) We all learnt in high school that energy is conserved. So don't you think that actual scientists know this too? Don't you suppose they take this law of nature into account? Or do you suppose that a bunch of Nobel Prize winning physicists have overlooked a principle of physics so basic and simple that I've known it since I was fourteen?

I guess in accuracy it's the sum of mass and energy that's conserved. But since most people don't work with nuclear reactions, we can say energy and mass are conserved seperately.

ok, tangent done.

 

[Dr Adequate]

Mass is energy.

 

[joobz]

Mass is energy.

They are two forms of the same thing, yes.