Second Law of Thermodynamics

[CraigD]

… For all its beauty and utility, thermodynamics is really just a collection of statistical laws, describing the exceeding likely, but not the absolutely possible. If “push came to crunch”, I suspect quantum mechanical law would trump thermodynamic.

…CraigD, can you explain more abt your last point?

I mean that thermodynamic laws are, in the final analysis, empirical laws. Their describe only what is exceedingly likely, not ultimately possible.

 

QM, or something very much like it, on the other hand, may be fundamental, so, if its absolute predictions conflicted with the thermodynamics’ likely predictions, we should credit the fundamental theory’s predictions, not the empirical one’s.

 

For example, some pre-big bang cosmological theories suggest that the pre-big bang universe was at a state of maximum entropy, then abruptly fluctuated into the low-entropy state of the instant of the big bang. I don’t agree with, disagree with, or well understand such theories, but they contain examples of predictions of QM “trumping” thermodynamics.

[insight]

I mean that thermodynamic laws are, in the final analysis, empirical laws. Their describe only what is exceedingly likely, not ultimately possible.

 

QM, or something very much like it, on the other hand, may be fundamental, so, if its absolute predictions conflicted with the thermodynamics’ likely predictions, we should credit the fundamental theory’s predictions, not the empirical one’s.

 

For example, some pre-big bang cosmological theories suggest that the pre-big bang universe was at a state of maximum entropy, then abruptly fluctuated into the low-entropy state of the instant of the big bang. I don’t agree with, disagree with, or well understand such theories, but they contain examples of predictions of QM “trumping” thermodynamics.

 

I really don't have that much knowledge to predict the pre BB theory. :hihi:

Before the giant explosion, the empirical soup was the within the boundary of singularity. I also don't know whether the soup had been cooked well or had not even boiled in that singularity. However, i must say that the soup is now cooling. Thermodynamics predicts the soup is cooked well before BB. On the other hand, if the soup is not cooked, it must be cooked to reach the boiling point (Big bang). (Note: it's just an analogy) Craig, how do you quote above?

[CraigD]

I really don't have that much knowledge to predict the pre BB theory. :hihi:

Who does, really?

Before the giant explosion, the empirical soup was the within the boundary of singularity. :cup:

Maybe not, according to some speculations. According to those, the universe may have been a big, uniform, non-singularity, then, due to a “quantum fluctuation” developed a disuniformity into which it collapsed into the pre-BB singularity.

 

All this pre-BB stuff is pretty wild and far-out. IMHO, we don’t yet have the formalism or intuition to have much of a chance of getting it right.

Craig, how do you quote above?

Check your Private Messages for how-tos and hints.

[coldcreation]

Are you talking about the first few miliseconds after BB? There were fluctuations then that made it possible for matter to be more prevalent than antimatter. But seems to me the overall effect was increasing entropy since more and more matter was created from energy. To reverse entropy would mean heating things up again. (?)

 

I would rather not deliberate on a theory based version of entropy. Especially regarding a theroy (big bang expamsion) which I absolutely do not believe.

 

I will say though, that because of mirror and charge symmetry, the laws describing electric particles are unchanged if left and right are interchanged, if positive and negative are swapped or if particles are replaced with anti-particles (if matter is replaced with the concept of antimatter). We also have Newton's laws of motion and Einstein's relativity, where the laws of nature are the same for every observer regardless of his position or motion, and this is why the speed of light is the same for all observers.

 

And so the laws describing the interactions of particles do not depend on the direction of time. Though, the second law of thermodynamics tells us entropy increases with time, generally. Thus, a physical basis for the direction of time from past to future is provided. And finally, this is why the universe along with all that it includes evolves steadily, dynamically, inevitably and irreversibly.

 

Entropy, meaning evolution in Greek, was defined by Clausius (1865). Here is his notable formulation: 'The energy of the universe is constant. The entropy of the universe is increasing.' Using current vocabulary we express Clausius's statement as:

 

'No process is possible in which the only net effect is to transfer a system's energy from a low temperature stable equilibrium state to a system in stable equilibrium state with a higher temperature.'

 

Coldcreation