Can't the universe be a sphere, and not flat?

Cosmologist talk about drawing a triangle on a sphere and it will come out to be over 180 degrees in the sum of angles. but that is on the surface. if you go inside the sphere and make a triangle then it should give the correct sum of angles. Not to mention, the universe may not be infinite, but the space it... show more Cosmologist talk about drawing a triangle on a sphere and it will come out to be over 180 degrees in the sum of angles. but that is on the surface. if you go inside the sphere and make a triangle then it should give the correct sum of angles.

Not to mention, the universe may not be infinite, but the space it takes up may be so large that as the human race as it currently exists, is not able to detect the minuscule change in the angles of the triangle

This is why I'm having a hard time accepting that the universe is flat. Can you please explain answers to this, and provide further evidence/support of the flat universe
14 answers 14