Why is flatness a problem is cosmology?

1 Answer
Aug 3, 2017

I suspect there are much more detailed answers available from cleverer people, but...

Explanation:

The Universe appears to have a value of Omega very close to 1. This means the internal angles of a triangle add to 180^@ which is very odd, because it is far more likely that there will be an excess of mass-energy in the Universe (meaning Omega would be greater than 1 and the internal angles <180^@) or too low an energy density, meaning Omega <1 and the internal angles >180^@.

It's just weird that it is so very close to 1, with no a priori reason for it having this value. Cosmologists, feeling honest, accept it's a bit embarrassing.

The Wikipedia article https://en.m.wikipedia.org/wiki/Flatness_problem is excellent.