There are three possible geometries of the universe: closed, open and flat from top to bottom. The closed universe is of finite size and, due to its curvature, traveling far enough in one direction will lead back to one’s starting point. The open and flat universes are infinite and traveling in a constant direction will never lead to the same point.

Universe with positive **curvature**. A positively **curved** universe is described by elliptic geometry, and can be thought of as a three-dimensional hypersphere, or some other **spherical** 3-manifold (such as the Poincaré **dodecahedral** space), all of which are quotients of the 3-sphere.

The **universe** could be positively curved, like a sphere. … In a **flat universe**, Euclidean geometry applies at the very largest scales. This **means** parallel lines will never meet, and the internal angles of a triangle always add up to exactly 180 degrees—just like you’re used to.

### Is there an edge to the universe?

Ballooning **universe**. But how can the **universe** be expanding if **there** is no end or **edge** to it? … That is, the concentration of matter in the **universe** is decreasing as the **universe** expands, she said. That’s because galaxies aren’t moving away from each other through space — it’s space itself that is getting bigger.

### Is there an end to space?

Whether **space** ever ends is a hard question. **There** is a limit to the **space** that we can see, because if **there** is stuff beyond 15 – 20 billion light years (the age of **the Universe**) the light from **there** hasn’t reached us yet. So we don’t know.

### What is at the center of the universe?

FYI: Where Is The **Center of the Universe**? First, it’s important to know that the big bang wasn’t an explosion of matter into empty space—it was the rapid expansion of space itself. This means that every single point in the **universe** appears to be at the **center**. Think of the **universe** as an empty balloon with dots on it.