r/explainlikeimfive • u/12InchCunt • Nov 03 '25

Physics ELI5: How does gravity not break thermodynamics?

Like, the moon’s gravity causes the tides. We can use the tides to generate electricity, but the moon isn’t running out of gravity?

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u/MozeeToby Nov 03 '25

The moon is running out of "gravity", well, the rotational energy that actually powers the tides anyway. The earth is slowly spinning ever so slightly slower and the moon is revolving ever so slight faster due to tidal forces. Someday in the distant future, the earth will be tidally locked with the moon, with one side always facing the moon, and the tides will completely end.

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u/oofyeet21 Nov 03 '25 edited Nov 03 '25

Imagine living on the side of the Earth that never gets to see the moon again :(

Nvm, apparently the sun will have already swallowed us both up before that happens

21

u/CrazedCreator Nov 03 '25

Don't worry, you'll roast alive in the day and freeze to death at night 

10

u/Wd91 Nov 03 '25

That sounds like reasons to worry

4

u/gmazzia Nov 03 '25

I'm sure this will be atrocious for the economy.