Imagine youre in a train car, and the shades are pulled over the windows. You cant see outside, and lets further imagine just for sake of argument that the rails are so flawless and the wheels so perfect that you cant feel it at all when the train is in motion. So just sitting there, you cant tell whether youre moving or not. If you looked out the window you could tell — youd either see the landscape sitting still, or rolling past you. But with the shades drawn over the windows, thats not an option, so you really just cant tell whether or not youre in motion.But there is one way to know, conclusively, whether youre moving. Thats just to sit there patiently and wait. If the trains sitting at the station, nothing will happen. But if its moving, then sooner or later youre going to arrive at the next station.In this metaphor, the train car is everything that you can see around you in the universe — your house, your pet hedgehog Jeremy, the most distant stars in the sky, all of it. And the „next station“ is tomorrow.