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Does Gravity Reduce Entropy?

  1. Dec 8, 2015 #1
    If gravity leads, for example to a gas cloud gradually coalescing into a proto-star, does this proto-star not have less entropy than the gas cloud that engendered it? If yes, then in what sense is overall entropy increased, in what way can we say that entropy globally has been increased via the collapse of the gas cloud into a proto-star?

  2. jcsd
  3. Dec 8, 2015 #2
    heat production
  4. Dec 8, 2015 #3
    So it would require more information to describe the motion of a proto-star's tightly-packed constituent atoms than than the random gaseous diffusion of atoms in a gas cloud? Seems counter-intuitive, which doesn't mean it's wrong though...

  5. Dec 8, 2015 #4
    It mainly requires not to consider the resulting proto-star only but also the emission of heat radiation (to ensure conservation of energy) and the expansion of the outer region of the proto-stellar disc (to ensure conservation of angular momentum) during the collapse.
  6. Dec 8, 2015 #5
    Ok, thanx DrS.

    What if we consider instead rock fragments drifting in orbit and collapsing into one solid meteorite? No significant radiation, no disk. This meteorite would likewise have to be much hotter than its original constituents?

  7. Dec 8, 2015 #6
    This or significant heat emission (within a sufficiently long period of time).
    Last edited: Dec 8, 2015
  8. Dec 8, 2015 #7
    Ok, thanx...
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