2006-10-08 22:48:23 · 4 answers · asked by tiksi 1 in Science & Mathematics ➔ Astronomy & Space
It means it has a boundary!
2006-10-08 23:24:29 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The most important thing about a closed universe as opposed to an open one is that in a closed universe, you can't go forever in a straight line without arriving back to the place where you started. This is because a closed universe has it's boundaries "attached" in some way.
For instance, think about an ant that somehow is inside a balloon. It could set out to walk in a straight line on the "ground," but it would eventually find itself back where he began. The inside of the balloon is like a two-dimensional closed universe for the ant.
In our universe, since it has three dimensions, it is not possible for us to draw or imagine what it means for the edges of the universe to be attached. The last I heard, though, scientists were in the midst of a study of the night sky to see if there are repititions in the view (I'm not sure how much good this will do since the view on a repitition would be unimaginably older and would have changed greatly). You see, not only can we not walk away from a place forever in a closed universe, we cannot see forever. If we were capable of seeing such vast distances as across the entire universe (assuming it is closed), we would see far, far in the distance, the other side of the earth.
This book is a great introduction to the concept, in my opinion.
2006-10-09 06:39:08 · answer #2 · answered by R.T.--Math Graduate Student 3 · 1⤊ 0⤋
Finate, or fixed. Not infinate.
2006-10-09 05:49:55 · answer #3 · answered by Harsh Noise Wall 4 · 0⤊ 0⤋
http://www.site.uottawa.ca:4321/astronomy/index.html#closeduniverse
2006-10-09 05:52:53 · answer #4 · answered by Anonymous · 0⤊ 0⤋