Eli5 If the universe expanded from a single point why do scientists say its flat and not spherical?

Question

Why would it only expand in one plane not every direction like you’d expect?

Also how is a flat universe even possible? Surely since we live in 3 dimensions the universe needs to be a 3 dimensional shape.

Im probably misunderstanding what physicists are trying to say but that’s why im here.

In: 229

Answer 1

‘Flat’ means if you walk in one direction, you won’t eventually loop back to where you started.

‘Spherical’ means that you will eventually loop back to where you started.

As far as we can tell, the universe is not spherical so if you keep walking in one direction you would not expect to loop back to where you started.