>>17722000DAILY REMINDER - GPS absolutely proves globe Earth, rotating Earth, space, orbiting satellites, time dilation (relativity), and gravity.
Flerfers will point to LORAN and claim that GPS could work off of transmitters sitting on the ground, on balloons, or on airplanes. But it cannot.
Why? I'm glad you asked.
In tracking mode GPS receivers use Doppler signal analysis to determine receiver velocity. It is impossible for a transmitter to fake Doppler signal shift to multiple receivers across 360°. If the transmitter was lying about its speed, then the receiver would think that it was moving at high mach based on the incorrect Doppler shift in the signal. And since GPS is computed in 3D space from four satellite signals, if the satellites were lying about their positions (altitudes) the resulting location and altitude on the receiver would be off by thousands of miles.
This means that GPS satellites are provably at orbital altitudes and speeds, because GPS could not function at all if the satellites were lying. And if the satellites aren't lying, then space is real. Orbits are real. But the dome is not real. Not unless the satellites punched through it.
What about Earth's shape? GPS receivers use a spherical model of Earth. If Earth was really flat, then receivers would report altitudes literally thousands of miles off. This means Earth really is a sphere.
Furthermore, both Earth's rotation and time dilation must be accounted for in GPS. If either one was not true then, once again, receivers would give obviously false and useless results. That means Earth really is rotating. And time dilation is real. And if both orbits and time dilation are real, that pretty much guarantees that gravity is real.
No single instrument completely shatters all of flat Earth mythology quite like the GPS constellation. It really is a beautiful thing.