4 ms·

Why can't Earth time be the universal frame of reference, and everywhere else use a factor of earth time? This article describes the rate difference already, wh

• andrewla 3y ago
  For the moon that potentially works because we're close enough to the moon that the drift is dominated by local gravitation rather than relative motion. But for any other context, say Mars, the problem is that the clock drift will be non-uniform. An hour on Earth (as measured by a precise clock on Earth) vs an hour on Mars as measured by a precise clock on Mars) will not be a fixed ratio, but will depend on relative position and velocities at the time that you start measuring the hour.
  • dpedu 3y ago
    Aren't those relative positions and velocities predictable enough? I believe NASA regularly makes predictions somewhat like this, such as when specific large asteroids are predicted to come near earth.
    • ianburrell 3y ago
      Sure, just like the relativistic effects of GPS clocks on Earth are predictable. But it makes clock keeping on Mars much more complicated, always making corrections. The corrections are always changing and syncing time is hard because the motions are always changing. Simplest solution is to use local atomic clocks. And then calculate Earth time when needed. All for zero benefit because the Earth is variable number of minutes from Mars so there will always be variation. Mars day is different from Earth have to calculate Earth time anyway.
      • Izkata 3y ago
        > Simplest solution is to use local atomic clocks. And then calculate Earth time when needed. Which is exactly what OP was suggesting, everyone else went off on a tangent.