Alex McColgan

Allow me to explain.

In a flat universe, if we were to form a grid to broadly represent reality, everything would seem fairly standard.

All the lines would either be parallel to each other or perpendicular.

An infinite universe of this variety would simply extend outwards in all directions forever and ever.

This is a little boring, so I won't spend too much time on it.

However, this is a lot like we perceive the universe to be.

For the most part, all lines of direction appear straight to us.

We can distinctly see the planets and stars around us, and we notice no real curving or warping.

However, this is not the only way that the lines can be drawn.

Consider for a moment a black hole.

You may immediately notice the strange rings that appear to run around its equator, as well as across the top of it and along the bottom.

This is something of an illusion.

There are no rings across the top or bottom of this black hole.

What you are seeing is the equatorial ring that's on the other side of the black hole.

However, due to the powerful gravity of the black hole, the light that is hitting it is not bouncing off upwards or downwards into space.

Instead, the rays are curving towards us.

As the black hole's gravity pulls them in, you are seeing the top and bottom of the ring at the same time.

Like being bent by gravity, what do I mean by that?

Actually, this is an excellent example of our second kind of universe.

In a flat universe, all the lines that make up reality are fairly straight.