Thermodynamics first law and time-invariance

[quantumtopology]

Classical physics is mostly time-invariant. In modern physics is seen as a goal and versions of quantum field theory and special relativity are also time-invariant. GR apparently doesn't satisfy it. All Standard cosmologies (FLRW cosmologies) don't conserve energy. They do not have the time symmetry needed to apply Noether's theorem.

 

I wonder ,When formulating physical models , should we concern ourselves with trying to make conservation of energy a key feature of our model, or in other words, is time-invariance a desirable goal for any physical theory "a priori"?

[modest]

This is worth the read,

 

Energy Is Not Conserved | Cosmic Variance | Discover Magazine

 

~modest

[quantumtopology]

This is worth the read,

 

Energy Is Not Conserved | Cosmic Variance | Discover Magazine

 

Thanks, I found that article by Sean Carroll last week and it kind of aroused my question, I thought it was an interesting debate theme and I wanted to know what people thought about it, I guess it's a little abstract issue.

 

Regards

[modest]

in other words, is time-invariance a desirable goal for any physical theory "a priori"?

 

I guess the stress-energy tensor is conserved, or time invariant. Individual non-gravitational components of the tensor, like energy, are not conserved... apparently...

 

Stress-energy tensor - Wikipedia, the free encyclopedia

 

~modest