## The Universe Closed Open or Flat

So then the universe expanded from this point in the Big Bang. What was the result? What is the architecture of the universe?

To begin to visualize the shape of the universe, we have to stop thinking like Newton and start thinking like Einstein. Remember that Einstein thought of gravitation not as a force that objects exert upon one another, but as the result of the distortion in space that mass causes. Einstein explained that the presence of mass warps the space in its vicinity. The more mass (the greater the density of matter), the greater the warp (the more space curves).

If the density of the universe is greater than the level of critical density, then the universe will warp (or curve) back on itself, closed off and finite. If the universe is closed, then our balloon analogy has been particularly accurate. In a closed universe, we think of the entire universe as represented by the surface of a sphere, finite in extent, but with no boundary or edge. If you shot out parallel beams of light in a closed universe, they would eventually cross paths.

If the density of the universe is below the critical level, an open universe will result. Whereas the spherical or closed universe is said to be positively curved, the open universe is negatively curved.

A closed universe is finite and without boundaries. A universe with density above the critical value is necessarily closed. An open universe will expand forever, because its density is insufficient to halt the expansion.

### Star Words

A closed universe is finite and without boundaries. A universe with density above the critical value is necessarily closed. An open universe will expand forever, because its density is insufficient to halt the expansion.

### Star Words

A flat universe results if density is precisely at the critical level. It is flat in the sense that its space is defined by the rules of ordinary Euclidean geometryâ€”parallel lines never cross.

A flat universe results if density is precisely at the critical level. It is flat in the sense that its space is defined by the rules of ordinary Euclidean geometryâ€”parallel lines never cross.

## Telescopes Mastery

Through this ebook, you are going to learn what you will need to know all about the telescopes that can provide a fun and rewarding hobby for you and your family!

Get My Free Ebook