4 ms·

Oh, I thought it was gravity alone that did the work :) Thanks for explaining it.

• fhars 14y ago
  Gravity doesn't do anything on its own, in the absence of other forces, the orbit of a steel nut around the earth would be stable (that's also why we haven't yet crashed into the sun even after being in its gravitational field for billions of years). (Well, you would get some instability because neither the earth nor the nut are perfect spheres or perfectly rigid, but those effects would take billions of years to become noticeable.)
  • gngeal 14y ago
    "Gravity doesn't do anything on its own, in the absence of other forces, the orbit of a steel nut around the earth would be stable" Actually, it wouldn't, because orbiting a celestial body radiates energy in form of gravitational waves, but in case of Earth's gravitational field and at the speed of orbiting satellites, this mode of losing energy is negligible.
    • fhars 14y ago
      Yes, but I still think that the tidal deformation of the earth under the gravitational influence of the steel nut will vastly dominate general relativistic effects like gravitational waves. You usually use neutron stars orbiting black holes to produce the latter.