Time Calculation of relativity

Today, I watched the popular science program in Central China 9,

First, it is about the earth satellite.

GPS satellite clocks are very precise, but must be calibrated several times a day every day in seconds. Otherwise, the navigation on the ground will have a 10 km deviation (because the speed is relatively different from that on the Earth, so the time series are different, but the GPS of the Earth needs to be calculated, so the clock needs to be synchronized with the Earth)

Then we will introduce that if a light-speed train traveling around the equator travels around the Earth 7 times a second, people on the train will travel around the earth after 1 week, and people on the train will get on and off the train in, that is. (Getting off is equivalent to synchronizing speed with the Earth)

It can be said that this is based on our Earth, and the time on the car slows down,

In fact, we can also think about the train as a reference, so our time is also slow. That is to say, if the train passes through 100 and our Earth's speed catches up with the train at this time, the result is the opposite: the train is in 2150, the Earth or in 2050.

The larger the mass of an object, the more space distortion. The slower the time passes,