4 upvotes, 3 direct replies (showing 3)
View submission: Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
If we created an unbreakable cable that was light enough to not change the moon's orbit could we attach it to the moon and a rail on earth that goes around the world to create energy?
Comment by GegenscheinZ at 20/07/2022 at 21:45 UTC
3 upvotes, 0 direct replies
An electric generator transforms kinetic energy into electrical energy, it doesn’t create energy. The system you describe will steal kinetic energy from the moon, slowing it down. The moon has a stupidly vast amount of energy due to is mass, so it would take like a billion years to notice the extra slowing.
Comment by the_muskox at 20/07/2022 at 20:17 UTC
1 upvotes, 0 direct replies
The earth and moon spin at different speeds, such a cable would get tangled around the earth as it spins.
Comment by x-seronis-x at 20/07/2022 at 19:09 UTC
1 upvotes, 0 direct replies
The moons orbit is already slowing down, thus making it get further and further from earth. So any rail you attach it to would get pulled off the ground eventually.
This 'slowing down' is due to the interaction of the tides on earth being pulled towards the moon but always trailing behind its orbit. THus the tides themselves pull back on the moon slowing it down and letting it drift further away. This also slows down the earths rotation. Eventually earths day will be 1 month long and will thus be tidally locked with the moon. Super far distant future stuff