But whose clock do we trust? No clock on this planet is in an inertial frame of reference. Over time, clocks at different latitudes and altitudes will diverge because they are moving at different speeds, even if they have the same atomic decay "tick" process. Which do we pick as the standard?
Even if one clock were picked, observations of when the clock ticked would vary over the planet as well.
Astronomical distant fixed points are more stable over long time spans than Earthbound clocks or the Earth's rotational and orbital characteristics, and the relative displacement with regard to Earthbound distance is negligible.
Even if one clock were picked, observations of when the clock ticked would vary over the planet as well.
Astronomical distant fixed points are more stable over long time spans than Earthbound clocks or the Earth's rotational and orbital characteristics, and the relative displacement with regard to Earthbound distance is negligible.