GPS Models!
Transcript:
So, GPS satellites are 20,200 km above the surface of the Earth, which is more than twice the diameter of the Earth. And when they are so far away up, the rate at which time passes for those GPS satellites is significantly different than the rate at which time passes for us on the surface of the Earth.
And this time difference has to be accounted for,
Except the model that is used to determine the surface of the Earth is a sphere, and it is close enough. We all know that t