3 ms·

> So there is at least a component of the "microseconds per day" offset formula that contributes to a slowing down compared to what is being orbited I'm not su

by pdonis 2y ago

> So there is at least a component of the "microseconds per day" offset formula that contributes to a slowing down compared to what is being orbited I'm not sure what you mean by "compared to what is being orbited". We are comparing a clock in a free-fall orbit to a clock on Earth. > speed matters but it is negligible compared to other factors for objects like the moon or a human made satellite For the Moon, yes, the speed effect is small compared to the altitude effect. For human made satellites, it isn't. For example, as I have already said, clocks on the ISS run slow compared to Earth clocks--because in low Earth orbit, the slowdown due to speed is greater than the speedup due to altitude.

alganet 2y ago
If the moon orbited earth a little bit faster, would the number of microseconds per day accumulated change (even if ever so slightly)? In other words, is the speed a determining factor in the offset? Your answer seems to indicate that yes. So, in principle, I should be able to come up with a thought experiment that highlights what that speed means. Would this hypothetical faster moon, billions of years orbiting earth at a different speed, look geologically younger than our regular speed moon? (genuine don't know, but that's the kind of coloquial illustrative example I'm looking for).
- pdonis 2y ago
  > If the moon orbited earth a little bit faster, would the number of microseconds per day accumulated change (even if ever so slightly)? Meaning, if you attached rockets to the Moon to speed it up while not changing its orbital radius? In that case the speedup relative to Earth clocks would be less, yes. > in principle, I should be able to come up with a thought experiment that highlights what that speed means I gave you one upthread, in the subthread where the movie Interstellar was being discussed. > Would this hypothetical faster moon, billions of years orbiting earth at a different speed, look geologically younger than our regular speed moon? Meaning, if you compared the two after billions of years of Earth clock time had elapsed? Yes.

by pdonis 2y ago

alganet 2y ago

If the moon orbited earth a little bit faster, would the number of microseconds per day accumulated change (even if ever so slightly)? In other words, is the speed a determining factor in the offset? Your answer seems to indicate that yes. So, in principle, I should be able to come up with a thought experiment that highlights what that speed means. Would this hypothetical faster moon, billions of years orbiting earth at a different speed, look geologically younger than our regular speed moon? (genuine don't know, but that's the kind of coloquial illustrative example I'm looking for).

pdonis 2y ago
> If the moon orbited earth a little bit faster, would the number of microseconds per day accumulated change (even if ever so slightly)? Meaning, if you attached rockets to the Moon to speed it up while not changing its orbital radius? In that case the speedup relative to Earth clocks would be less, yes. > in principle, I should be able to come up with a thought experiment that highlights what that speed means I gave you one upthread, in the subthread where the movie Interstellar was being discussed. > Would this hypothetical faster moon, billions of years orbiting earth at a different speed, look geologically younger than our regular speed moon? Meaning, if you compared the two after billions of years of Earth clock time had elapsed? Yes.