WARNING : Please add me to your ignore list if you dont like my random babbles on here. I would like to appologize to those who dont but I have so many questions that I cant figure out how to word that I need to do a random babble once in a while so please stop reading now if you are not into that sort of thing


I was randomally thinking about eternity. What eventually happens in an expanding universe.

At the same time I was thinking about a contracting universe model where parts of the universe are contracting. For example I believe that near a black hole space is contracting.

Then I thought that how can we say the universe is expanding when there are parts of the universe that are contracting.

Then I started to think about what would happen over time.

If the universe continues to expand forever what would happen?

Galaxies would move farther and farther away ( I have questions about this also but lets address that at a different space-time )

however galaxies themselves would eventually be sucked into the blackhole in their center ( is this mainstream??? ).

so we would have a universe of distant blackholes moving farther away from each other.

Then again my question arose as to what is space-time and how could there be nothing in space-time. My understanding is that space-time can not exist without gravity. ( would it even make sense ??? ) So if all we had were massive gravitational forces then how could the universe still expand when their tendancy would be to contract?


The next thought that came into my mind was this:

Picture two funnels connected by the small end ( who knows maybe the big end, maybe both ends ) with stuff flowing from the large end into the small end into the connected small end then out the larger end of the other funnel.
picture this flow in both directions.

\ /
||
||
/ \

As stuff exits either the small end or the big end of either funnel it has to travel at relatively the speed of light.

Now I am not sure but I thought that at the speed of light time stops and that mathmatecally time reverses at speeds past the speed of light. If ther ewas a time reversal ... maybe into another funnel ( either connected at the large end or the small ) it would flow either into the small end or the large ...


I guess what I am saying is that there seems to be some flow into black holes or off the edge of our universe ... at both places it seems that the universe is pulling back time equal to the speed of light ... if on the other end there was another universe that was contracting ( blue shifting ) or time reversed ... then it would absorb from either end and could in theory emmit back into our universe ( or a similar universe ).

OK ... my brain hurts ...
Not sure if any of this is a question but would love if people could correct me where I am wrong.

OK ... I guess this didnt make sense at all?

The point I think I was trying to make was that black holes and the edges of our universe where the universe is exapnding at faster than the speed of light seems somewhat familiar to me. Except that one is receeding away due to gravity ( compression ) and the other is receeding due to expansion.

Do you think that, out where the distant galaxies at the edge of our observable universe are right now, the universe is expanding any faster than it expands in the region around our galactic cluster?

If we look at a galaxy 9.1 billion light years away and consider it to have receded from this point in space at the speed of light in the time since the universe began, then anyone in that distant galaxy right now who was looking at this point in space would think the same thing - that where we are has receded from them at the speed of light in the time since the universe began.

We are the centre of our observable universe and they are at the centre of theirs, so where would these black holes actually be?

Space-time almost everywhere is expanding relative to us faster than we are expanding relative to us! ? ! ?

We think that the gaps in between the galactic clusters expand at pretty much the same rate throughout the universe at any given time.

Distances in between galactic clusters at the edge of the universe are increasing right now at the same rate as the distances between the galactic clusters are increasing over here, right now

Simply put, the whole universe scales up at only one rate at any given time, but it is the change in that rate across time that adds up to an increase in apparent recession speed.

Wherever you put yourself in the universe, the closest galactic clusters outside your own seem to be receding the slowest and the most distant clusters seem to be receding the fastest, but this is an effect of the expansion of the universe and the travel time of light, nothing made of matter is actually moving through the space around it at the speed of light or faster.

So, do you think that, out where the distant galaxies at the edge of our observable universe are right now, the universe is expanding any faster than it expands in the region around our galactic cluster (right now)?

Hmmm ... relative to what? To all rulers? But how about in places of the universe that is compressing like near a black hole?

OK let me think this out. If you have a black hole with an event horizon x. Space-time relative to ALL rulers expands ... then wouldnt the event horizon and possibly the singularity of the black hole also expand?

I just dont get that ... then are there exceptions to the ALL rulers case??? Then it is a furhter reach for me ...

An apparent recession speed relative to yourself, of course! All rulers across the universe now are scaling up at the same rate. This leads to a view of the universe where the further you look, the faster things look like they are receding from you

Take a volume of space and fill it with a 3D grid of points, all the same distance apart from each other on all three axes. If the whole volume expands at the same rate, your nearest point seems to recede from from you the slowest and the furthest point seems to recede the fastest but every point is receding from the point next to it at the same rate! And the view is the same, whatever point you choose to use as your viewpoint.

If points in space are originally 1,2,3,4,5 etc light years away, and the volume of space expands to twice its original size (and the grid expands with the volume), then those points will now be 2,4,6,8,10 light years away. If the expansion took only 1 billion years, then the first point has receded from 1 to 2 light years away in a billion years, but a more distant point has receded from 5 to 10 light years away in the same period of time. So the further point looks like it is moving faster than the nearest point. The nearest has moved 1 light year in a billion years, while a more distant point moved 5 light years in a billion years. A point originally 1 billion light years away will have moved to 2 billion light years away in a billion years and so will have apparently receded from you at the speed of light.

But none of those points are actually moving at the speed of light - the view is the same whatever point you choose as your frame of reference.

I understand and appreciate everything you wrote EXCEPT:
I dont think all rulers scale up. In fact rulers in an near a black hole scale down. Now you may mean rulers will tend to all scale up at the same rate ... but I would also find that hard to believe although more believable that ALL rulers. in fact ... in your post you state 2 things :
1) An apparent recession speed relative to yourself, of course!
2) All rulers across the universe now are scaling up at the same rate.

My problem is that I dont see the logic jump from one to the other. Although I can appreciate the desire to make that leap of faith.

Wow, Tommac, synchronicity – I was thinking about this problem/approach last week and hoping to discuss. My idea is that as galaxies eventually collapse into the black holes at their centre, we will have a universe of black holes – is this possible? After that, what happens to time? Could there be a black hole universe for trillions of years, or 10^trillions of years? Over that eternal period, surely the outward movement from the Big Bang would dissipate, and the underlying gravitational attraction would cause these black holes to stream together into a big black hole, which over further eternal aeons would form a new singularity? Could the laws of physics somehow change after all matter in the universe is inside a black hole?

Oops, I can see I did mislead you here. I meant to say that distances as measured by rulers scale up at the same rate, not the rulers themselves of course. It is the apparent recession speed relative to your ruler that increases over time.