>>17214011I'm not asking you to believe me, I gave you a way to measure if the earth is a solid object (buy a Richter scale, wait for a large earthquake about 45° around the globe from you) and a way to measure the rotation of the earth (a sensitive gyroscope, ring laser or mechanical) so you can use that to prove yourself right or wrong.
Or, if GPS has to use land based relays (since if we are in a cylinder there would be no space and therefore no satellites) figure out a way to prove that's the case, I'd suggest climbing to a fairly high altitude (so the ground based radio waves could still reach you from the towers) then cover the GPS receiver from above with a hemispherical faraday shield. If you still get a lock on your location from 3 satellites then you may have a point.
You could buy a weather balloon kit and send up a camera that's images down to you.
Each option should cost <$10k, some cheaper than others.
Or you can just go outside and look at the sky and spot a starlink satellite shoot by every few minutes.
