But when the train changes speed by either accelerating or decelerating, there’s a force (and if you’re standing up, it might just manage to knock you over). Your body is the mass, and when acceleration is zero-when the train is moving at a constant speed-there’s no force on your body. That’s because of a basic law of physics: force = mass * acceleration. When a train slows down or speeds up, we can feel the resulting force on our bodies. There is one important difference between a train and Earth. The air inside the train (and the atmosphere that surrounds our planet) moves along at the same speed we do. But if we viewed Earth from the frame of reference of space, we would be able to see the twirling instantly.Īnd just like passengers seated on a train, we don’t have any clues-like wind rushing through our hair-to make us realize how fast we’re going. From inside the Earth’s frame of reference, we can’t tell that we’re spinning. The same is true of Earth and space, but at bigger scales. Standing on the platform, the train moves. From either frame of reference, you feel like you’re the one staying still. But from the inside, you’d feel like you were standing still while the world moved by. If you were standing on the station platform, you would clearly see the surface was standing still while the train whizzed by. A person standing on a train has one perspective-one frame of reference-and a person standing on a station platform has another. That’s because Earth and the train are both what physicists call “frames of reference.” Frames of reference are kind of like perspectives. You can’t feel yourself spinning on Earth for the same reason that you can’t feel yourself moving while you’re on a train. So why can’t you feel it? Your stomach goes all topsy-turvy when you spin around on a merry-go-round, and that’s a lot slower than 1,000 miles per hour. Congratulations: you’re currently spinning at about 1,000 miles an hour without even trying! That’s how fast the Earth has to turn to make a complete rotation every day.

Can we feel the earth spinning