Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 02/03/2007 19:35:31

Title: How big was the Universe when it was a billionth of one second old?
Post by: neilep on 02/03/2007 19:35:31

If it was possible to freeze the universe at say a billionth of a second old, and that it was made habitable (human friendly)...what would happen when you reach the edge  ?.......or would it appear that you go round in circles if I continued in a straight line ?

How big was it at a billionth of a second old anyway ?.............

Just in case it's still too big at that age.......then forget about the age and say that when the Universe was a mile big !..OK ?

Hugs & Shmishes


Neil
xxxxx

Title: Re: How big was the Universe when it was a billionth of one second old?
Post by: another_someone on 02/03/2007 21:28:30

The issue is not really whether we could exist in a universe a billionth of a second old, but rather, whether we could exist as an entity that is bigger than the universe itself.  When the universe was but a small dot, so everything within it (ourselves included) were even smaller dots, so the edge of the universe would still have seemed as far as ever in relation to our own size.

As for whether the universe could be frozen in its early history - the real question probably should be whether anything (whether us, or anything else) could have escaped the Big Bang in its early years - i.e. was there any time when the Big Bang was expanding at less than the speed of light, so that light (or even gravity) could have outrun the leading edge of the Big Bang.

Title: Re: How big was the Universe when it was a billionth of one second old?
Post by: neilep on 02/03/2007 23:07:06

Ooooh !!...then where would all that ' i'm going outside I may be some time ' stuff be if it was outside the Big Bang !!?...

I think even a billionth second old Universe would be quite big though...big enough to swing a cat in !!...so..I'm asking a fantastical fantasy type question that assuming we could be what we are now and that the Universe could in fact be just a mile wide then would we hit something in a mile or just go round in circles ?

Title: Re: How big was the Universe when it was a billionth of one second old?
Post by: that mad man on 03/03/2007 16:52:12

A billionth of infinity is still infinity so there would be no edge or centre!

TMM

Title: Re: How big was the Universe when it was a billionth of one second old?
Post by: neilep on 03/03/2007 21:44:07

Is it really infinite ?..really ?

As far as I understand ......... at the beginning the entire universe was compressed into a teensy weensy yellow polka dot bikini of a state.....and then......from nothing.......expanded like a balloon.

Is this not the generally accepted understanding ?

Title: Re: How big was the Universe when it was a billionth of one second old?
Post by: another_someone on 04/03/2007 02:53:31

Quote from: neilep on 03/03/2007 21:44:07

Is it really infinite ?..really ?

As far as I understand ......... at the beginning the entire universe was compressed into a teensy weensy yellow polka dot bikini of a state.....and then......from nothing.......expanded like a balloon.

Is this not the generally accepted understanding ?

In this context, what is meant by infinity?

If you are on the inside of a black hole, then you can ask, if you were travelling at the speed of light, how long would it take you to reach the event horizon of the black hole, and the answer is that it would be an infinite time to reach the event horizon, and so one might say that from insode the black hole the event horizon is an infinite distance away.  Yet, looking at the black hole from the outside, the event horizon has a finite size.  So, does not infinity depend upon one's perspective?

The Big Bang may have been teensy weensy on the outside, but what was it on the inside (after all, on the insode, there was an awful lot of mass that would have been distorting the space around it)?