Naked Science Forum

On the Lighter Side => New Theories => Topic started by: timsouhrada on 24/08/2009 03:53:08

Title: giant vacuum cleaners
Post by: timsouhrada on 24/08/2009 03:53:08

big bang happens.  matter disperses.  gravity attracts.  black holes form.  black holes get bigger and attract each other.  eventually blackholes converge into one.  all space in universe converges into one point.  matter reaches critical mass.  explodes again.  repeat.  am i wrong?

Title: giant vacuum cleaners
Post by: lyner on 24/08/2009 11:44:53

We still don't know whether the Universe is Open, Closed or Flat - do we?

Title: giant vacuum cleaners
Post by: Nizzle on 24/08/2009 12:46:25

Not to mention:

1. Black holes get bigger: yes
2. Black holes are drifting away from each other: yes

Will all black holes converge into one, or in other words, Is 1. happening faster than 2.?: who knows?

Title: giant vacuum cleaners
Post by: Vern on 24/08/2009 14:00:39

Who even knows whether Black Holes are real? There may be some unknown principle that limits the density of mass.

Title: giant vacuum cleaners
Post by: LeeE on 24/08/2009 16:25:46

Quote from: sophiecentaur on 24/08/2009 11:44:53

We still don't know whether the Universe is Open, Closed or Flat - do we?

If we accept that the rate of expansion of the universe is increasing then I don't think the universe can be closed.  A path through a universe that continues expanding forever will take you through 'new' space, as new space is being constantly created by the expansion.  If the expansion were to slow and eventually stop, but without subsequently contracting again, then I think it could be regarded as open and flat, but it wouldn't be flat until it reached the point where expansion stopped.  If the universe were to stop expanding and then start to contract, then I think it could be regarded as closed.

This is just looking at space though, and doesn't take time into consideration, which it really must as we're actually talking about spacetime.  From our point of view, we seem to be always moving in to 'new' time, but what we can't tell is whether we are just moving along a static line of finite length or whether we are actually located at the endpoint of the that line, with 'new' time being constantly added at the end, just in front of us.

Interestingly enough, although the expansion of space seems to occur pretty much all the way throughout it, this doesn't seem to be the case with time, for if time were to expand in the same way as space then things in the past would be getting further away from us i.e. something that happened one hundred years ago would be further than one hundred years in the past.  Mind you, I'm not sure what it would look like to us if it did happen that way.  The way it actually appears to us is that all the 'new' time is ahead of us, so instead of 'new' time being added throughout time, it is added to the 'end' of the time axis.

I think that the phenomenon of 'now' further indicates that we are at the end of the time-line rather than being at some point along it.  If we are at the end of the line then things can still run at different time rates, with the apparent amount of 'new' time being added in front of everything being dependent upon it's particular degree of time-dilation, so that 'now' is still the same for everything.  If we were just at a point somewhere along the line though, then running at different rates of time would leave everything in different places and 'now' wouldn't be at the same point along the line for everything.

Title: giant vacuum cleaners
Post by: Don_1 on 25/08/2009 08:51:55

What you suggest, is, in a nut shell, about the same as I do.

See this thread http://www.thenakedscientists.com/forum/index.php?topic=23165.msg254149#msg254149 (http://www.thenakedscientists.com/forum/index.php?topic=23165.msg254149#msg254149)