Is the universe a sphere?

1 Answer

The universe is believed to be many shapes which varies as following:

  • Flat and infinite/finite
  • Curved like a shell and finite
  • Curved outwards and infinite

These are not certain or proven.

Explanation:

The shape of the universe depends on its density. If the density is more than the critical density, the universe is closed and curves like a sphere; if less, it will curve like a saddle. But if the actual density of the universe is equal to the critical density, as scientists think it is, then it will extend forever like a flat piece of paper.

Credit: NASA/WMAP Science team.
- Source http://www.space.com/24309-shape-of-the-universe.html#sthash.U0SWOLu3.dpuf

There are also different religions that believe the shape of the universe conforms to their beliefs.

A common belief is also that space is a "fabric", which is actually kind of true, as space is not an absolute void as "dark matter" exists in space. The movie "Interstellar" showed the "fabric" of space being warped accurately as it would by relating it to multiple theories.

But to reiterate, the universe isn't proven, but theorized to be:

  • Flat and infinite/finite
  • Curved like a shell and finite
  • Curved outwards and infinite