Science Forums 2

[C1ay]

Originally Posted by EWright

I'm saying what the concensus among most cosmologists seems to be. I did read the 156Gy diameter article in SciAm a year ago and found it very interesting. But cosmologists need to then decide if they want to use this figure or the 13.7Gy figure that is most often quoted.

In either case, it doesn't matter. If you are going to say that the universe is finite, then you must be able to say what it is expanding into. But by definition, the universe is all that there is. It may be that what is beyond the observable universe is very different than what we see (though unlikely if you use the bb model). But in both cases it is believed, as I understand it, that the universe is still believed to be infinite in size in the sense that it wraps back around on itself and if you travel in a straight direction you will end up back where you began (after a very long voyage).

Because you can go around something and end up where you started, it cannot be infinite. If it were infinite you would never get around it.