Expanding time?

I agree with your first sentence and have all the time, the universe gets bigger and encroaches on nothing.The difference is that you and the 99% see nothing in one way, as having no attributes whatsoever, whereas I see there being a negative attribute to it, an endless absolute vacuum.I even agree about the distance paragraph, I stated almost exactly the same in within a week of being on this site way back in 2004?Your third paragraph is the problem, you make an assumption of [possibly] the Cosmos as infinite 'universe' of you are right then what you say is correct, but it is a big 'if', we can assess the age of the 'universe' [cosmos, is my term] and it is all we have but it is not infinite, we know the rate of growth and we can extrapolate the distance to the true edge of your universe or my cosmos.Einstein was not certain at all that the universe [cosmos] was infinite, he was split over the matter and could and was swayed by argument and counter-argument.In reality CD little divides except the chasm of how we view the nothin-ness beyond existence.The small detail of negative attributions of the void on my side of the argument changes physics beyond measure, I don't believe there has been a true 'zero' [cosmoslogically] since existence came about, the void before existence was a null, a zero, but from the moment of existence it had a negative value.It is as hard to comprehend [it seems] as Einsteins relativity the concept of negative space and negative properties of the void, but it far from 'nonsense'.

I thank you for three paragraphs of explanation. And I will read them again carefully.But, I do not understand what you are saying.As for Einstien's Theory of General Relativity, I suspect there are a small handful of people on the planet who can claim to REALLY understand it inside out.I ain't one of them.OKay, maybe a lot more people can claim to REALLY understand it inside out.But cosmology does fascinate me and always has.I will say that I am not sure if infinity in a practical sense really exists. I could be wrong. But at present I think infinity maybe only exists in the mind as a concept.Now, I am going to go back and read your post another time.Edited by jaywill, : No reason given.

Don't worry, this is not easy, especially an esoteric subject like expansion of space. All of our simple analogies can be abused to bolster incorrect claims such as those of V-Bird, so I am jumping in at the deep end with you to try and avoid this.This may or may not help... here are three galaxies:

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They are 100 megaparsecs apart ( about 326 million light years)

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Now they are 200 megaparsecs apart.

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Now they are 300 megaparsecs apart.Nothing has changed apart from this number we call distance. It will take longer to travel beween them, but that is all. There is no edge to this space either. If this universe is infinite, we can keep looking further and further left of these three galaxies, meeting more and more galaxies, all of which are also getting further away from each other. If this universe is not infinite, if we look left far enough, we will get back to where we started from! There is no edge which is expanding into some outer nothingness (as V-Bird believes). There is just the Universe. The distances between the galaxies is growing larger, but that is all.Edited by cavediver, : No reason given.

CD,This is addressed to you. Anyone can answer though. In the last sentence, I have difficulty seeing the difference between the two ideas.I think I also may contradict myself when I say infinity in a practical sense may not exist. But this vacuum or whatever beyond the two farthest "things" as you called them, well that may be the only infinity.I mean the two "things" with the biggest number discribing how far one is from the other.What are your thoughts on these two questions?1.) Years ago someone told me that if you travel in the universe in one direction long enough you will come back to the same place you started.Is that an accepted concept ?2.) Many things in the universe are rotating. Do you think that the whole universe may be rotating also ?]Edited by jaywill, : No reason given.

That is because you are still visualising the Universe as some ball that is growing. That viewpoint does not exist. You have to look at the Universe from the inside, as only the inside exists. In an infinite universe, there is no biggest number, and in a finite universe, you will simply start overlapping yourself as you describe larger and larger distances. You could describe New York and Sydney as a million mile apart, if you're willing to go round the earth several times before actually landing! If the Universe is finite this is quite possible, though you can't actullay do it because the space is expanding more quickly than you can travel. Imagine that the earth is expanding. It may expand so fast that you could never fly fast enough to get all the way around! Good question. Probably not, given the type of cosmology we seem to inhabit. But it is possible to have rotating space-times.

Correct me if I am wrong cavediver, but from my understanding there would be no way to tell if the universe is rotating without an outside point of reference. Since the universe is defined as the spacetime dimension in which we reside, there in essence cannot be anything outside of this universe which could be considered a point of reference outside.The only other way to determine if our universe was rotating would be to somehow be able to observe our universe from another dimension other than the 4 dimensions of spacetime i.e. the brane-bulk cosmological theory which suggest that there are higher dimensions in which our spacetime universe resides. This brane-bulk cosmological theory is still theoretical and not proven. However, it makes the most sense mathematically and provides valid explanations for previously unanswerable physics questions such as why gravity is so weak.

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For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan

Word of Warning in concern of V-Bird: I would agree with CaveDiver, that V-Bird, at the least, misconstrues modern cosmological theories accepted by the whole of the scientific community and, at the most, deliberately misinforms people with unsubstantiated giberish. I am not sure what his motives are (i.e. selling a book, etc) but in my opinion, I would totally ignore him.And no I am not being bigoted nor do I think V-Bird to be less intelligent than me (I cannot make that type of value judgement). I just don't think it is fair for unsuspecting members to think that he speaks for the whole of the scientific community when he obviously does not.Edited by DevilsAdvocate, : No reason given.

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For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan

Oh, okay We could have a nice deep dicussion of Mach's ideas here, but I'm knackered so for now I'll simply say that in General Relativity, we can distinguish a rotating space-time from a non-rotating space time, from inside that space-time. A great example is the Kerr rotating black hole which differs significantly from the Schwarzschild non-rotating black hole. Edited by cavediver, : No reason given.

Oh yes, I forgot Newtons spinning bucket hypothesus and Mach's discussion of whether there is a space "ether" from which we could determine the affect of centrificul forces on the water inside the bucket. Something to that affect. I would have to do some further reading on this as well .

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For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan

Yep, that's the stuff. When you spin round, would your arms lift up if there were no other stars and galaxies It's sort of sad that most of this is answered by GR, but there are still some mysterious areas...

Your three little @ would from any viewpoint not remain the same size if the gap increases.A more accurate representation [ignoring the difference in the icon shape] would be:-
@@ @** *.. .There is no position in space where the three galaxies would appear the same size!If that was the case the Crab Nebular and the largest clusters would be enormous in our night sky.So you are wrong to say that nothing has change except the distance, the diffusion of light sees to that alone.Edited by V-Bird, : failed attempted to rectify locations.

Remember what I said about abusing analogies...?At the given scale, you would only see pin points for galaxies. And their size is irrelevant to the point I'm trying to make.

1/. The viewpoint may not exist but that is not the same as saying the shape does not exist! We are within the ball and forever confined to that position in a cosmos expanding as fast as our messenger [light] so we can never see that surface.2., The cosmos is expanding from a singular point and is drawn out from all directions at once, they may be huge turmoil at the 'edge' or cusp but the cosmos itself is unlikely to rotate, but it cannot be discounted entirely. Again we are within the cosmos and just as if you were under ground you would not perceive that the earth is rotating we are inside the cosmos and cannot know.

I don't think it is abusing an analogy, it is pointing out a potential fault in it.The plain fact is that at any scale, the there would be perceivable changes in them, size or brilliance, it makes no difference.With increasing distance there are changes in what we perceive and that applies from any point in the cosmos.Relativity cannot be suspended, it is omnipresent.To view those objects equally would mean we would have to magnify them progressively and that means either surrounding galaxies disappear off the lens or the lens has to get bigger, again this happens from any position within the cosmos.Edited by V-Bird, : late and tired

Actually spacetime is expanding faster than light not "as fast as light". In fact the inflation of the universe is accelerating at an increase pace. No, spacetime itself is stretching out in 4 dimensions (3 of space and 1 of time) from singularity. As pointed out by CD there is a way to determine if the universe is rotating but it is rather complex. All I know is that it has something to do with centrifugal forces as proposed by Ernst Mach. CD would you like to expound on this?

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For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan