Three-torus model of the universe

The three-torus model of the universe is like a giant donut. The universe looks the same no matter which way you look at it. Think of it like a video game, where if you go off one side of the screen you show up on the other side. That's what the three-torus model of the universe looks like. Our universe might be like a donut that's curved in three directions, one direction up, one direction down, and one direction left to right. The whole universe fits inside the donut, and every part of the universe connects to itself in some way. That means that no matter where you go, if you keep going long enough, you will eventually end up back where you started.