Reverse Entropy, Reverse Causality And Physical Laws

[schmu]

Hello, I do not have any scientific education and I am far away from understanding relativity, quantum mechanics and such.

I am just wondering about entropy, causality and if we could reverse these in a thought experiment without violating the physical laws of the "universe".

Is it possible to look at the "universe" disregarding our perception of the arrow of time and assume that entropy, causality, laws of thermodynamics are relative without violating the laws of physics?

Could we assume that the laws of nature such as entropy and causality are reversed? Eg. the arrow of time is relative and entropy increases over time, cause and effect are reversed - the universe didnt "start" with the big bang, but rather started as a system in a state of high entropy?

Do some laws of physics forbid to think of the universe in such a model?

Im aware this might appear like a stupid question and i dont expect huge detailed answers, but if someone could give me a link to some research or thought experiment that goes this direction?

thanks alot!

[exchemist]

Hello, I do not have any scientific education and I am far away from understanding relativity, quantum mechanics and such.

 

I am just wondering about entropy, causality and if we could reverse these in a thought experiment without violating the physical laws of the "universe".

 

Is it possible to look at the "universe" disregarding our perception of the arrow of time and assume that entropy, causality, laws of thermodynamics are relative without violating the laws of physics?

 

Could we assume that the laws of nature such as entropy and causality are reversed? Eg. the arrow of time is relative and entropy increases over time, cause and effect are reversed - the universe didnt "start" with the big bang, but rather started as a system in a state of high entropy?

 

Do some laws of physics forbid to think of the universe in such a model?

 

Im aware this might appear like a stupid question and i dont expect huge detailed answers, but if someone could give me a link to some research or thought experiment that goes this direction?

 

thanks alot!

I'm fairly sure this is not a silly question. Not trivial at any rate. :)

 

As the 2nd Law of Thermodynamics is one of the laws of physics, any thought experiment that presumed the total entropy of a closed system would decrease with time would obviously have to violate this law, by reversing its predictions.

 

But it is interesting because, according to my (rather old and imperfectly remembered) understanding, one of the profound paradoxes of thermodynamics is that while each individual physical interaction at the micro level is in principle reversible (applying Newtonian or Quantum mechanics as appropriate) , the overall evolution of an ensemble of interacting entities is in general not reversible. (It is only reversible in the special case that the entropy of the system does not increase during the evolution of the system.) 

 

The irreversibility arises from probability, as there are in general more ways of arranging an ensemble in a disordered way than in an ordered way. The classic Maxwell's Demon thought experiment is a good way to visualise this. https://en.wikipedia.org/wiki/Maxwell%27s_demon

 

(I have to say that Statistical Thermodynamics is, in my opinion, one of the beautiful concepts in physics and chemistry, as it shows how the simple ordered world of our macroscopic laws arises from micro scale randomness, applied within the constraints of quantum mechanics.)  

 

I am conscious of thrashing around a bit, trying to get hold of a satisfactory answer to your question, but I think I am going to say that your thought experiment requires a suspension of the laws of probability, which is a denial of a concept in mathematics - which is a form of logic. And so it cannot be logical!

 

But I'm open to challenge on this chain of reasoning.  

Edited February 3, 2018 by exchemist