The violation of conservation laws

[MarkE]

Entropy is a statistical law, an approximate conservation law. Shouldn’t therefore this “law” be added with ‘…most of the time’, instead of implying that it’s always the case, by using the term “law”?

By introducing Maxwell’s demon, he visualised how this 2nd law of thermodynamics is about probability, an unlikeliness, a statistical impossibility, but not an absolute impossibility. Therefore violating the 2nd law is a statistical possibility, which can only be violated with a tiny probability, but on average entropy doesn't decrease (like throwing heads 1000 times in a row instead of tails).

Emmy Noether discovered that with every conservation law there’s a symmetry involved. There’s for instance always a conservation of charge, a related principle to Maxwell’s equations. Since entropy is an approximate conservation law, entropy therefore shouldn’t be symmetrical, always and everywhere. I’ve always thought that Maxwell’s equations are beautiful and symmetrical, but I guess the only symmetry in these 4 equations can be found in the wave function of the photon itself (like all bosons, in contrast to the asymmetric wave function of a fermion), and not in the equations themselves. In this video (at 2:30 minutes) the lack of symmetry (between the 1st and the 2nd equation) is also mentioned. 

Am I making the right judgements and conclusions here?

Edited March 14, 2018 by MarkE

[Strange]

Entropy is not conserved so I ... uhm ...

 

[swansont]

Also, the second law originated in classical physics. There are statements based on this, rather than on quantum mechanics.

You might notice that we have not restated the law of conservation of energy despite the Heisenberg uncertainty principle, for somewhat similar reasons.

[MarkE]

36 minutes ago, swansont said:

You might notice that we have not restated the law of conservation of energy despite the Heisenberg uncertainty principle, for somewhat similar reasons.

Good point. They're all called "laws", not a-law (absolute) versus r-law (relative), unlike the clear distinction between mRNA (messenger), tRNA (transfer) and ncRNA (noncoding).

Edited March 14, 2018 by MarkE

[MarkE]

OK, so all of the above statements are correct? I didn’t make any wrong assumptions?

One other question then: if entropy can sometimes be violated, what would be a good example of this happening here on Earth? When and where has it been observed? 

[swansont]

A law in science is a mathematic relationship that has been observed to be true. They are limited in their applicability (e.g. you have Ohm's law, but it doesn't apply to certain devices). In this case, they do not apply to short time scales, where you might have a fluctuation. 

[Moreno]

On ‎3‎/‎14‎/‎2018 at 10:02 AM, MarkE said:

Good point. They're all called "laws", not a-law (absolute) versus r-law (relative), unlike the clear distinction between mRNA (messenger), tRNA (transfer) and ncRNA (noncoding).

 

22 hours ago, MarkE said:

OK, so all of the above statements are correct? I didn’t make any wrong assumptions?

One other question then: if entropy can sometimes be violated, what would be a good example of this happening here on Earth? When and where has it been observed? 

On Earth it can be observed occasionally on nanoscopic level. You need an electronic microscope to observe something like this. Hardly on a larger scale. 

There is an interesting question regarding Universe heat death and giant thermal fluctuations. How likely is it and how many modern scientists do believe that the observable part of Universe is the result of a giant thermal fluctuation?

[MarkE]

1 hour ago, Moreno said:

On Earth it can be observed occasionally on nanoscopic level.

Interesting. Where/when?

1 hour ago, Moreno said:

There is an interesting question regarding Universe heat death and giant thermal fluctuations. How likely is it and how many modern scientists do believe that the observable part of Universe is the result of a giant thermal fluctuation?

Also interesting! "Thermal fluctuations provide the energy necessary for the atoms to occasionally hop from one site to a neighboring one". Seems like some kind of quantum tunnelling.

[Bender]

On 14/3/2018 at 1:31 PM, MarkE said:

(like throwing heads 1000 times in a row instead of tails).

For any macroscopic system, it's more like throwing heads eg 10^20 times in a row. You can throw coins from the beginning of the universe to the very end: it will never happen.

Edit: In retrospect, throwing heads 1000 times in a row already qualifies for the "will never happen" category. So you only need a system of roughly that amount of degrees of freedom / particles to completely ruin your odds of decreasing entropy with a tiny amount. 

Edited April 3, 2018 by Bender