Now you explain to me how that works with navigation on the stars the old-fashioned way.

Hey, I could also say something. Well, you measure the angle between a star and the horizon with a sextant. You know that you are therefore on an imaginary circle that all have the same angle to that star. You then measure another star as quickly as possible and you are also on that imaginary circle. These 2 circles have 2 intersections, so you don't know exactly yet. Of course you can guess. That's why you need a third meeting. And the closer those lines intersect, the more accurate your position is. You often do a fourth measurement as a check. But then you had to be good as a navigator. I once saw a very happy captain when we sailed from New Zealand to the Panama Canal. It is then quite important that you know your correct position in relation to Central America. Otherwise you will end up wrong and sail on top of the beach of Costa Rica. It was cloudy the whole trip and then it is difficult to shoot a star. Still I had managed to get a correct position through the clouds.

 

Clear story. Your GPS actually does exactly the same thing, only it does not measure the angle between the horizon and the star, but measures the  t i j d  that takes the signal to get from the satellite to you. As a result, you also get circles from that position as you were talking about. There's just one important thing. The time on the satellite must be the same as that of your GPS. And that is not so because of 2 factors. The relative speed of the satellite relative to you is many times higher. Such a thing stands at an altitude of 20,000 km from the earth's surface. And we've just seen that as relative velocity increases, time slows down according to Albert E's special theory of relativity. It's minimal, but it plays a role.

A second factor is gravity. As gravity increases, time slows down. The satellite experiences less gravity than you do, so your time is slower than the satellite's.

If these times were not corrected, your position could drift 11 km per day. And of course that is not possible.

So here's some real-world proof that theroom andtime be able tochange