3 ms·
I think it’s the rotational inertia of the earth, not the kinetic energy of the moon. Since the earth is spinning faster than the moon orbits, the tides actuall
by hinoki 4y ago
I think it’s the rotational inertia of the earth, not the kinetic energy of the moon. Since the earth is spinning faster than the moon orbits, the tides actually are pulled ahead of the bulge the moon creates, transferring energy from the earth to the moon.
Eventually the earth will be tidally locked to the moon (just like the moon is to the earth), and the moon will be in a higher orbit.
I guess the turbines will speed this up? As they’ll keep the bulge farther ahead of the moon.
EDIT: Wikipedia link https://en.m.wikipedia.org/wiki/Tidal_acceleration https://en.m.wikipedia.org/wiki/Tidal_acceleration
- jameshart 4y agoThat's true - for some reason I was thinking of tides as following the moon's orbit, when of course they're caused by the earth spinning underneath the moon (tides occcur daily, not monthly. Always check your working against reality, kids). Weirdly, the resulting pool of energy is pretty much the same size - wikipedia quotes the rotational kinetic energy of the Earth as being 2.138E29J. So we're still talking about an insane amount of energy. If you use 17.7TW as the total power consumption of all of humanity, if we were to somehow derive ALL of our energy needs from tidal generation, it would take 358 million years to deplete the rotational energy of the earth.
- usrusr 4y agoWould the turbines make the rotation decay faster, or would they just put some of the energy of rotation decay that happens anyways on a slightly different path towards heat?