Einstein’s theories can be tough to understand, even for grown-ups, but here’s a simplified explanation: In special relativity, Einstein said that time and space are linked together and can change depending on how fast you’re moving. In general relativity, Einstein said that gravity is not a force pulling objects together, but rather the effect of matter curving space and time. Think of it like a bowling ball on a trampoline - the ball creates a dent in the trampoline and any smaller object nearby will be drawn towards it. Einstein’s theories also helped explain the behavior of light and how it travels through the universe.