3 ms·
Entropy can't be reversed, even if you have a massless, frictionless, motor that doesn't need to be plugged in. That is effectively what Maxwell's demon is.
by bb88 5y ago
Entropy can't be reversed, even if you have a massless, frictionless, motor that doesn't need to be plugged in. That is effectively what Maxwell's demon is.
- deleted 5y ago[deleted]
- tsimionescu 5y agoOf course entropy can be reversed, I literally do it in my sleep! However, reversing entropy requires an amount of energy commensurate with the amount of entropy you are reducing. Maxwell's demon would appear as a violation of this. A massless, frictionless motor could trivially reverse all the entropy in the universe given enough time, but it is not clear that Maxwell's demon REQUIRES something equivalent.
- bb88 5y agoMaxwell's demon requires erasure which would subsequently increase entropy. https://www.nature.com/news/the-unavoidable-cost-of-computation-revealed-1.10186#:~:text=Landauer's%20theory%20offered%20the%20first,entropy%20lost%20by%20the%20demon https://www.nature.com/news/the-unavoidable-cost-of-computat....
- tsimionescu 5y agoAs someone else was noting, this result is based on Landauer's limit, which is itself ultimately based on the second law of thermodynamics. If Maxwell's demon existed, the second law would be wrong, so Landauer's limit would be wrong, so there could be a way to erase information without increasing entropy. I'm also not sure why Maxwell's demon would require erasure.
- bb88 5y agoWikipedia summarizes this well. https://en.m.wikipedia.org/wiki/Maxwell%27s_demon https://en.m.wikipedia.org/wiki/Maxwell%27s_demon I think it's clear that by now the 2nd law always wins. Always.