Re: I'm confused
when we say "the universe", we're referring to the sphere of space we can observe. this so called "observable universe" contains everything from which electromagnetic radiation has had time to reach us.
the universe is 13.7 billion years old. however, because space itself is expanding, the radius of the observable sphere is about 46 billion light years.
the further we look, the older the light is - right back to the cosmic microwave background, around 380,000 years after the big bang. we can't see beyond that point because the earlier universe was opaque.
Biting the hand that feeds IT
