ELI5: Explain Like I'm 5

Elevator paradox (physics)

The Elevator Paradox is about what happens to our feeling of weight when you are in a moving elevator. When the elevator moves up, we feel heavier than when it moves down.

Think of a person standing on a scale inside an elevator. When the elevator is still, the scale reads your weight, like it normally would. But when the elevator begins to move, you suddenly feel heavier and the scale will read more than your normal weight. When the elevator goes up, it feels like you weigh more and the scale reads a higher number. When the elevator goes down, it feels like you weigh less and the scale reads a lower number.

This is the Elevator Paradox. Even though your actual weight hasn't changed, it seems like you weigh more or less at different times in the elevator.

The reason for this has to do with acceleration. Acceleration is a change in speed or direction. When you stand in the elevator and the elevator begins to move, you feel an extra push called an acceleration force. This force makes it feel like you weigh more. When the elevator slows down or goes down, you don't feel that extra push and so you feel lighter. That's why you seem to weigh more when the elevator goes up and less when the elevator goes down.