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A comment on Scientists Watch as Heat Moves at the Speed of Sound. Parent comment

Re:Scientists Watch as Heat Moves at the Speed of Sound by arithma on Sunday March 24, 2019 @09:56AM (#19476347)
Not a "Real Physicist" but the information is not being lost, it's only being kept static-ish. This is the same as that waves don't violate the 2nd law (it's telling that they being called the phenomenon second sound.)

> The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time.

So instead of entropy increasing, it's hanging around for a while. No violation, still unusual though.

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Re:Scientists Watch as Heat Moves at the Speed of Sound by sp332 on Sunday March 24, 2019 @12:15PM (#19477088)
Heat often correlates with entropy, but they are not the same thing. Increasing heat doesn't always mean increasing entropy.
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Re:Scientists Watch as Heat Moves at the Speed of Sound by EngineerBetter on Sunday March 24, 2019 @01:06PM (#19477410)
I'd highly recommend Arieh Ben-Naim's books on entropy for anyone looking for more on this point.

TLDR he makes the argument that entropy is a measure of the probability of probability distributions.

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Re:Scientists Watch as Heat Moves at the Speed of Sound by tgtweak on Sunday March 24, 2019 @10:54AM (#19476665)
Doesn't seem as if total entropy is increasing, simply rebalancing to the other side (which is still kind of interesting, like a wave in a pool).
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Re:Scientists Watch as Heat Moves at the Speed of Sound by hannasanarion on Sunday March 24, 2019 @10:59AM (#19476692)
Yep, and energy is lost in the rebalancing process, and it oscillates until equilibrium, just like a pendulum.
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