Because the GPS system takes into account both Special and General Relativity. That means both speed and mass. If it didn't then it would be unusable.
I just had a look at the satellite navigation formulas and none
of the formulas have any elements that could represent mass
and the only element that could represent speed that I could
find is "c" for the speed of light in a vacuum.
none of the elements in the formulas could possibly represent
satellite mass or satellite speed or any earth based GPS
locator systems speed ...
also the math used DOES NOT contain any of the designer math
that is used to prop up the einstein theories.
and thats most likely why it works so well...
https://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equationsplease point out where satellite mass or satellite speed is located in ANY of the formulas.
the only elements I found are
transmitter time , receiver time
position x , y , and z
also why would a GPS system need to incorporate the designer
einstein math when the orbital velocity is only 3.9 km/s?
are you suggesting that there would be any differences in time
between the clocks on earth and the onboard clocks on a
satellite traveling at such slow speeds in a earth orbit?
I think the whole idea is rather silly myself because someone
on the earths equator is basically orbiting the center of the
earth at apx .44 km/s
(not much of a difference compared 3.9 km/s)
that would mean that someone at either pole would undergo
a drastic time difference when compared to someone at the equator
and we dont seem to have experienced any serious
time differences so far.
so why should a satellite?
same thing goes for mass.