ALMA sees old galaxies before they merged. two ways to look back into the past?

[Seattle]

Hence my proposition that all this is happening within an infinite but timeless permittive condition which contains neither time nor space.

Time goes on even in an infinite universe. Where do you get any evidence that there is no time nor space?

 

[Write4U]

Time goes on even in an infinite universe. Where do you get any evidence that there is no time nor space?

But that would alter our definition of the universe as we know it, wouldn't it? How could we speak of an expanding universe if it were already infinite in size?

A Hilbert Hotel model?

 

[Seattle]

But that would alter our definition of the universe as we know it, wouldn't it? How could we speak of an expanding universe if it were already infinite in size?

A Hilbert Hotel model?

That has nothing to do with your comment about their being no time or space.

I don't know anything about a Hilbert Hotel and I have no comments about infinity. The evidence that we have is limited to the Big Bang and red shifting being explained by expansion.

 

[Write4U]

That has nothing to do with your comment about their being no time or space.

I don't know anything about a Hilbert Hotel and I have no comments about infinity. The evidence that we have is limited to the Big Bang and red shifting being explained by expansion.

I understand that.

But it is the conflict between the estimated time of the BB and the estimated size of our universe (spacetime) which confuses me.

Trying to think this through, I recalled the Hilbert paradox also known as the Hilbert Hotel.

Hilbert's paradox of the Grand Hotel, or simply Hilbert's Hotel, is a thought experiment which illustrates a counterintuitive property of infinite sets. It is demonstrated that a fully occupied hotel with infinitely many rooms may still accommodate additional guests, even infinitely many of them, and this process may be repeated infinitely often. The idea was introduced by David Hilbert in a 1924 lecture "Über das Unendliche" reprinted in (Hilbert 2013, p.730) and was popularized through George Gamow's 1947 book One Two Three... Infinity.

https://en.wikipedia.org/wiki/Hilbert's_paradox_of_the_Grand_Hotel

Perhaps this may not have any bearing on our discussion, but somehow it seemed to present a similar paradox. I am really interested in any comment.

 

[Xelasnave.1947]

Hence my proposition that all this is happening within an infinite but timeless permittive condition which contains neither time nor space, except for our and possibly other universes, i.e a multiverse.

Moreover, we have estimated the possible end of our universe, at least as we know it.

Should I interpret that to mean our universe is finite?
Alex

 

[Xelasnave.1947]

How could we speak of an expanding universe if it were already infinite in size?

You can add or subtract from infinite yet it will remain infinite.
A finite Universe expanding would seem difficult as well I mean the first thing someone asks here is what is it expanding into.
There is only one way to sort it out.
Can you hold this end of my tape measure while I check?
Alex

 

[Seattle]

I understand that.

But it is the conflict between the estimated time of the BB and the estimated size of our universe (spacetime) which confuses me.

Trying to think this through, I recalled the Hilbert paradox also known as the Hilbert Hotel.
https://en.wikipedia.org/wiki/Hilbert's_paradox_of_the_Grand_Hotel

Perhaps this may not have any bearing on our discussion, but somehow it seemed to present a similar paradox. I am really interested in any comment.

We don't even know if the concept of infinity has any bearing on reality so it's a little hard to discuss. I don't really (without any evidence) buy that concept.

I don't know why you have any problems with the time since the Big Bang (approx. 14 billion years) and the estimated size of our visible universe. No one is estimating the size of the entire universe so you can't have any problem with that.

 

[Write4U]

Should I interpret that to mean our universe is finite?
Alex

In context of age it would seem so.

 

[Seattle]

You can add or subtract from infinite yet it will remain infinite.
A finite Universe expanding would seem difficult as well I mean the first thing someone asks here is what is it expanding into.
There is only one way to sort it out.
Can you hold this end of my tape measure while I check?
Alex

I don't particularly have a problem with the concept of a finite expanding Universe. I don't know that asking what it is expanding into is necessarily a question with any meaning.

That "might" be similar to asking what happens when you get to the end of the Earth.

 

[Write4U]

We don't even know if the concept of infinity has any bearing on reality so it's a little hard to discuss. I don't really (without any evidence) buy that concept.

I don't know why you have any problems with the time since the Big Bang (approx. 14 billion years) and the estimated size of our visible universe. No one is estimating the size of the entire universe so you can't have any problem with that.

I don't, but then how can we tell the age of our universe as a separate object created by the BB ?

Perhaps the universe has always been an infinite timeless condition (nothingness), and the BB was the release of pure energy from a singularity which became responsible for an expanding volume of matter which we named "the (our) universe" and given it the properties of "spacetime"?

 

[Xelasnave.1947]

I don't know that asking what it is expanding into is necessarily a question with any meaning.

I don't ask it but I have seen it asked on many occasions.

That "might" be similar to asking what happens when you get to the end of the Earth.

We all know the answer ... There be monsters and past them you fall off the edge of course.
Back to the first part.
A student asks you " Sir, what does the universe expand into?"
Can you give an answer without involving a flat Earth.
Alec

 

[Seattle]

I don't ask it but I have seen it asked on many occasions.

We all know the answer ... There be monsters and past them you fall off the edge of course.
Back to the first part.
A student asks you " Sir, what does the universe expand into?"
Can you give an answer without involving a flat Earth.
Alec

My answer would be the same as my response here. I don't know, and it might be a question without meaning. There might not be anything outside of the Universe so that question might not have meaning.

There may be no meaning to the question, "What came before the beginning of our Universe" (if there was a beginning).

Sometimes you just have to deal with what we have evidence for and say "I don't know" for the rest.

 

[Seattle]

I don't, but then how can we tell the age of our universe as a separate object created by the BB ?

Perhaps the universe has always been an infinite timeless condition (nothingness), and the BB was the release of pure energy from a singularity which became responsible for an expanding volume of matter which we named "the (our) universe" and given it the properties of "spacetime"?

Again, you seem to be conflating two things.

Your second paragraph is conjecture as to what was before the BB. Great. No one knows the answer to that at the moment. That's why we start with the BB.

Your first question really has little to do with the second question. You ask how do we know how old our Universe is (since the BB). My understanding is that it is just the physics involved and predictions that we now have evidence for.

The short answer is the CMB (Cosmic Microwave Background). The BB made certain predictions and those were born out. Starting out with how hot the Universe was and how cool it should be today and how that initial radiation would be distributed results in the current age of our Universe.

 

[NotEinstein]

Iqualified it as an an abstract POV

So you agree that when you wrote "The illustration is looking at the universe from a side view" (post #7) and "from an observation point outside the universe" (post #9), that was non-sense. OK, we agree there.

No, it was an illustration which seemed to exite Hawking as a new hypothesis.

That is not a response to my statement.

Agreed, but if that is approximately true then multiplied by SOL, we should be able to calculate to an approximate size (not counting the inflationary epoch), no?

Of the visible universe, yes. But that only sets a minimum bound on the size of the total universe. If I am standing in a closed room inside a building, I have no way (in general) to determine how large the building is; I can only set a minimum size for it (namely, the size of the room).

Where did I dispute this, if I recall I stated that we have estimated the age to be ~ 14 billion years from the "back ground noise" (CMB).

(You had a quote in your post that wasn't mine, seemingly attributing it to me.)

Nor have I, The illustration in direct response to the OP question which asked if we could see past the center

Wrong; the OP doesn't mention any center at all; that was you in post #3.

(the beginning) where original 3 D expansion started. I offere the new hypothesis that it is possible that the BB formed a bell shaped universe, as if it were spewing from a white hole (another domension?)

A white hole is not "another dimension"; please learn what a dimension (in physics) is.

and was not the center of a 3 D sphere but the beginning of our universe.

Again, it was you bringing up the "center of a 3D sphere", not anybody else.

I have read of the possibility that other dimensions may have bumped and our unverse was created from a single point which is expanding going forward in time in a form of a ringing (contracting and expanding) bell shape.
An interesting thought.

Yes, the ekpyrotic theory of brane cosmology is interesting, but at the moment, it's merely a hypothesis. Unless branes were explicitly the topic at hand, I would stick with standard cosmology.

that was in context of a slice of time, a 2 D crosssection of the current cone. If we looked across this slice we would not be looking back in time toward the "beginning" but across the universe as it exists today.

Ah, OK, understood. Note that this is not possible in practice, due to the finite speed of light. In reality, the further out we look, the further into the past we observe.

I agree, but You admit that we don't know for sure the shape of the universe, and the assumption that it must be a 3 D sphere is also speculative.

Nobody in this thread is making that assumption but you.

No, if the universe is a sphere it must have a center, or you cannot call it a sphere.
And if we don't even know if the universe is finite then how can we approxomate it as 92 billion light years in size , which is a measure of distance?

The visible universe is (roughly) spherical, and has an obvious center (us!), but the universe itself doesn't. Please stop confusing the two!
​

That's an assumption on your part.

No, that's not an assumption; please look up what an assumption is. Saying "we don't know if X" (truthfully) is not an assumption of any kind.

I find it an interesting idea.

It certainly is! But it's quite speculative at the moment, and it seems weird to introduce such a speculative idea in response to the OP. In fact, it's quite irrelevant to answering the OP, so I'm not sure why you even brought it up.

The illustration clearly shows that at each slice of time of the circular 2 D plane cross section of the bell is expanding from it's previous state, but it also shows a wave like function which would tend to support Bohm's Pilot Wave model.

Our current expansion of the universe may well stop expanding and start contracting for awhile, before it continues its expansion. The current circumference of the universe may be the crest of the Pilot Wave at this time, before we descend into a trough where the circumference of the universe shrinks for awhile before we expand to an even larger size in the future.

Note that in the illustration this wave like process has 7 distinct crests and troughs, each lasting billions of years. A very long wave length.

That's irrelevant to what we were discussing. Seattle explained it to you in post #30: do you understand what (s)he said there resolves your issue, yes or no?

 

[Xelasnave.1947]

Sometimes you just have to deal with what we have evidence for and say "I don't know" for the rest.

You have the correct answer.
So few, actually just you and me, can provide such an honest answer.
Alex

 

[Write4U]

You have the correct answer.
So few, actually just you and me, can provide such an honest answer.
Alex

I agree we need to work with what we know, but IMO, it is never too late to ask questions or offer another approach that may shed new knowledge from a different perspective.

If Galileo had not questioned Aristotle about his theory that heavier objects tend to fall faster then lighter objects, which is true on earth but with false proof, but was corrected (expanded) by Newton's Law of falling bodies, which is a universal phenomena. Even so it took about 2000 years for this "correction" to be made..

 

[Write4U]

Time goes on even in an infinite universe. Where do you get any evidence that there is no time nor space?

The theory that spacetime (our universe) is limited in age and size.

 

[nebel]

Wrong; the OP doesn't mention any center at all; that was you in post #3.

Thank you for all your replies, While I did not directly mention a center, it was implied, since in an expanding universe, there would not be two path in opposing directions to any event, or would there? We are all still in the center, it looks that way! and so is everybody else, from their viewpoint!?
Is my misunderstanding really about the expansion rate versus the speed of light?
What is the universe expanding into? how about into time, if that is a fundamental 4st
dimension?
ranting: if there was a point in time at the BB, there was a small center, that has now expanded to the confines {perimeter}of the universe. so we were both at the former center and are all now the extreme reach?

 

[Write4U]

Thank you for all your replies, While I did not directly mention a center, it was implied, since in an expanding universe, there would not be two path in opposing directions to any event, or would there? We are all still in the center, it looks that way! and so is everybody else, from their viewpoint!?
Is my misunderstanding really about the expansion rate versus the speed of light?
What is the universe expanding into? how about into time, if that is a fundamental 4st
dimension?

Or a timeless pemittive condition? A nothingness which creates it's own Imperative, such as a vacuum that demands to be filled, even as that demand creates a dynamic singularity.

ranting: if there was a point in time at the BB, there was a small center, that has now expanded to the confines {perimeter}of the universe. so we were both at the former center and are all now the extreme reach?

Good and logical questions, IMO. In a multiverse, where each separate universe is created by a similar event as the BB, each universe would have it's own center from which that universe expanded, would it not?

Can you have a multiverse inside our universe ? If not, then how could other universes begin? Don't we call those smaller universes inside our universe Galaxies?

Simultaneous creation of a multiverse is a possible answer, however those universes would still be in apart from our universe, no?

 

[Xelasnave.1947]

Don't we call those smaller universes inside our universe Galaxies?

No we call them galaxies. However before galaxies were understood they did refer to them as " island universes".
Alex