Cosmology

RE: Question - Same in All Directions?

kkkzzz — Fri, 20 Feb 2004 22:13:29 GMT

Not to take anything away from AlsoPhobos, but it seems to me that both zero and infinity are imaginary -- they are concepts. After all, there are infinite subdivisions between 1.0 and 2.0, and infinite subdivisions between 1.0 and 1.1, and infinite subdivisions between 1.0 and 1.01, and infinite subdivisions between 1.0 and 1.001, and ... you get the idea.

Hyperspace, among several other books, describes some ways of contemplating infinity.

Is our universe infinite? I say infinity is everywhere and yet nowhere. The question itself must be stated differently.

RE: Question - Same in All Directions?

AlsoPhobos — Fri, 20 Feb 2004 18:53:44 GMT

Current evidence indicates that the universe is "flat", which like "open", means that it is boundless (essentially infinite). Based on the finite speed of light, our "visible universe" (what we can see based on what light is available to us) is about 13.7 billion light years in every direction. So, our "visible universe" has a diamter of about 27.4 billion light years. Our visible universe grows by 1 light year per year. The whole universe is bigger than that. With Big Bang theory, you would expect that our visible universe is a typical slice of the whole universe. Of course, there are no actual observational data available outside of our visible universe, so there is some uncertainty in that. Anyway, an astronomer 13 billion light years away from us could see an additional 13 billion light years further IN THAT DIRECTION from us. He/she/it could no see the 13 billion light years of stuff on the other side of us that we can see.

RE: Question - Same in All Directions?

aristaeus63 — Thu, 19 Feb 2004 17:42:41 GMT

I have often wondered this myself. Does this mean that the universe is 26 billion LY wide. I don't think so. I think it implies another spacial dimension. I can envision it in my head this way. When you stand on a globe and look in any direction, assume there are no obstructions to your view, the horizon is the same distance every way you look. To get to the point, on the globe, exactly opposite were you are is the same distance no matter which way you go. Maybe the 13 billion LY is just the horizon and the universe is a 4 or greater dimensional globe.

Andreas

Question - Same in All Directions?

Daniel Longest — Thu, 19 Feb 2004 16:51:08 GMT

Since our observable universe appears to be the same in all directions, does it appear the same in all directions from the galaxies we observe 13 billion light years distant? From those galaxies, are galaxies observed 13 billion light years away in all directions?