The universe began as a singularity... not at single point?

Question

The person I chose as having the best answer really got me thinking.

http://answers.yahoo.com/question/index;_ylt=Ar5WxZAO8gRqaMvo0CTXA7Tty6IX;_ylv=3?qid=20080709081357AASKtdu

I always thought everything started at a single point during the Big Bang, but Raymond said that the universe originated from a singularity... a singularity not being a single point. I found this very interesting as I cant really visualize it.

And hasn't it been said that around one second after the Big Bang the universe was the size of a grapfruit correct? If the universe could be infinite than its size should not have been finite at any point in time... so whats the deal? Please elaborate on this idea.

Answer 1

http://en.wikipedia.org/wiki/Big_bang#Ti...

one second in, it was FAR bigger than a grapefruit

Answer 2

a singularity is basically a single point. its a 0 dimensional point, like in geometry.

the universe is not infinite. anyone who says so is out of touch with science. an infinite universe requires one of two things. a) an infinitely old universe. or b) a universe in which relative mass does not exist. without relative mass particles could travel infinitely fast.

obviously relative mass exists in our universe, so that option is out. so the only other option is an infinitely old universe. this flys directly in the face of the big bang theory. you cannot subscribe to both theories, it does not work.

Answer 3

When addressing questions about the 'size' of the universe I always try to avoid the concept of infinity. Infinity literally means no beginning, no middle, no end. Unless the Big Bang theory is totally wrong, our universe did have a beginning.

Extrapolation from the present back to the moment of the universe's creation implies an origin of  limitless density and temperature existant within zero volume, i.e., a cosmic singularity. Such a singularity only has a mathematical existence and is prevented from having a physical existence by what can be called 'cosmic censorship.'

Answer 4

The universe was not a single point, because that implies a 3d plain.  For there to be a point in space, there has to be a space.  

The most common misconception about the Big Bang is that it was simply the mass of the universe that was a singularity at the beginning, but in fact space itself didn't exist before the Big Bang.

Answer 5

The furthest back that we can claim to understand roughly what was going would be the end of inflation--about 10^-32 seconds after the theoretical time zero.  The universe was pretty big at that point.  Anything before that is quite speculative.  So postulating a singularity or even universe-in-a-grapefruit is way, way out there.

http://en.wikipedia.org/wiki/Timeline_of...