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

[Write4U]

I always like to look at fellow surfers, I like sharing a wave. so: how come , looking along that break, I can see event of those galaxies merging? where is the image of the united entity along the wave in my line of sight??

Everything we can observe . Considered the distances we are talking about. The universe is so big it staggers the mind and we can actually observe only the largest of events and even then we can only see maybe a small percentage of the original, such as an undefined little blob, which in reality might be as big as our entire galaxy.

That is an interesting wave of energy we are riding. it's crest length curves right back into the smaller and smaller space. Us pointing the board into the future.

There is a difference between water waves and the Universal Pilot Wave.

The de Broglie–Bohm theory, also known as the pilot wave theory, Bohmian mechanics, Bohm's interpretation, and the causal interpretation, is an interpretation of quantum theory. In addition to a wavefunction on the space of all possible configurations, it also postulates an actual configuration that exists even when unobserved. The evolution over time of the configuration (that is, the positions of all particles or the configuration of all fields) is defined by the wave function by a guiding equation.

https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory

Consider that we see stars today which no longer exist at all. They went nova millions of years ago and their light hasn't reached us yet.
Moreover when we go back that far in time we don't see things anymore. We receive EM (radio) waves from only the largest events and objects. Now that we are in space and can look further back we can see more, but still older events are stil only observable via EM waves.

 

[Write4U]

nebel said: ↑
The one dimensional time representation post 3 are difficult I think, for we look back into time to the beginning, no matter where we look, an expanding sphere, looking along the surface helps me more.

Don't forget that we are always inside the slice of time. The illustration is merely trying to give an approximation of the universe looking at it from outside of the universe, which of course is physically impossible.

The size of the universe is unimaginably large. We can translate some of it with mathematical equations , but even those are really beyond our ability to imagine. We just haven't enough neurons in the brain to process even a very small part of it and even then have to make mental best guesses of what's out there. That's why maths are so important, they can lead us to answers which would otherwise be completely beyond our experience.

 

[Xelasnave.1947]

The News item said it showed the old galaxies in the process of merging, but they have merged since, so, where is that younger image? has it moved, shrunk? past us by?

The other night I was observing Andromeda (M 31) our closest galaxy similar to us, the Milly Way.
One needs to remember what you see come from photons that have been travelling for 2 million years. Neat.
M31 is visible with the naked eye at a dark site so if someone ask how good are your eyes one can say, assuming you have good vision, I can see something 2 million light years away.
If you get the chance have a look at it thru binos it appears to fill half the field of view. Spectacular.
Alex

 

[Seattle]

Andromeda is interesting to mention in the context of this thread as well because our Milky Way galaxy and Andromeda are on a trajectory to merge in the future.

 

[Xelasnave.1947]

Andromeda is interesting to mention in the context of this thread as well because our Milky Way galaxy and Andromeda are on a trajectory to merge in the future.

Yes and nothing is being done to prevent it...time to panic.

Alex

 

[nebel]

The old galaxy that we are just now seeing will have changed but we can't see that because it's so far away that not enough time has passed for us to see those changes.

seattle thank you! my confusion results from the impression that the new development is closer in time to us therefore should be traversed in a shorter time, I am confusing space with time. the space distance is the same, but the new image left later, when it became available. will arrive in the future.
The cucumber space time image with matter flowing through time to the right is right and good, but I prefer to see the beginning in the center, time more pervasive, space in the form of an expanding 2D shell.

 

[Seattle]

seattle thank you! my confusion results from the impression that the new development is closer in time to us therefore should be traversed in a shorter time, I am confusing space with time. the space distance is the same, but the new image left later, when it became available. will arrive in the future.
The cucumber space time image with matter flowing through time to the right is right and good, but I prefer to see the beginning in the center, time more pervasive, space in the form of an expanding 2D shell.

Just in case you aren't clear, nothing is expanding from the center. Everything is expanding except locally bound matter.

The example usually given is putting dots on a balloon and blowing it up or baking bread with raisins in it. The dots or raisins maintain their relationship between each other but everything just moves further apart.

This isn't like an explosion with everything radiating out from the center.

 

[NotEinstein]

is clearly deriving properties of the univetruth from that picture, indicating you take the picture

to be an accurate depiction. (Not sure how that got cut-off?)

Write4U: I assume your lack of response to my post #13 means you agree with everything I said in it?

 

[Write4U]

Yes you did, in your post #9:

For there to be an observation point outside of the universe, there must be a position outside the universe for that observation point to take.

So you are saying there are 5 dimensions? I just called it an illustration from an abstract POV.

And if you were talking about it being an accurate depiction of the universe, your post #5:
is clearly deriving properties of the univetruth from that picture, indicating you take the picture

Does that incoherent statement warrant a response?

Correction: visible universe, at best. We have no idea how large the universe is, or if it's even finite in size.

Then how can we claim it is ~14 billion years old? There seems to be a contradiction in terms here.

Age may only be a number, but when it comes to the age of the universe, it's a pretty important one. According to research, the universe is approximately 13.8 billion years old.

I got the picture of a wavelike (bouncing universe) in relation to this article, which seems to have captured Hawkins attention. http://www.ibtimes.co.uk/how-was-un...heory-only-speculation-says-physicist-1650382
Perhaps you don't agree with it.

Actually, it is. The further you look away, the more into the past you are looking.

I believe I also said that.

A plane does not have a center, so that's incoherent.

So the illustration of a bell shaped universe beginning with the BB is hopelessly flawed? I am not defending that , but Hawking seems impressed with that hypothesis in the above link.

But If I understand the thrust of your argument, the universe would have to be a 3D sphere with the BB at its center. Am I correct in that?
How could one take a slice of time (as illustrated in the link) from a 3 D sphere with the BB at its center?

The universe as illustrated is a bell shaped configuration starting from a singularity and expanding which allows for a universal slice of "now" at every point in time.

But how could you make a slice of time from a 3 D sphere or measure it at all?

How big is the universe?
Sticking us at the center of a massive sphere, the currently observable universe has a diameter of about 92 billion light years. Even with this observed distance, we know that it extends much further than that.

Can you reconcile 14 billion years of time since the beginning, with 92 billion light years in diameter?

 

[Seattle]

Can you reconcile 14 billion years of time since the beginning, with 92 billion light years in diameter?

Light has been travelling for 14 billion years in all directions and the universe has been expanding. That is where the 92 billion light year diameter comes from (for the observable universe). The universe expands faster than the speed of light from our perspective and therefore there are parts of the universe that we could never see thus the distinction between the observable and non-observable universe.

 

[NotEinstein]

So you are saying there are 5 dimensions? I just called it an illustration from an abstract POV.

It's you who's suggesting that, not me. You claim that illustration is an accurate depiction of the universe. You claim it's possible to take a position outside of spacetime (thus introducing a new space-like dimension).

Does that incoherent statement warrant a response?

I've so far given responses to all your incoherent statements as well, so... But seriously, I already indicated in my post #28 something went wrong. (I see what happened now; the textbox in my browser keeps jumping my cursor around; not sure why. The text was mangled.) Let me coherentify it:
"is clearly deriving properties of the universe from that picture, indicating you take the picture to be truth."

Then how can we claim it is ~14 billion years old? There seems to be a contradiction in terms here.

Because we can only see ~14 billion years in the past? Because that's the lifetime of the universe one derives from the CMB? This is basic GR!

For the record, Write4U seems to quote me as saying: "Age may only be a number, but when it comes to the age of the universe, it's a pretty important one. According to research, the universe is approximately 13.8 billion years old.", but I never said that.

I got the picture of a wavelike (bouncing universe) in relation to this article, which seems to have captured Hawkins attention. http://www.ibtimes.co.uk/how-was-un...heory-only-speculation-says-physicist-1650382
Perhaps you don't agree with it.

I have not formed any opinion on this bouncing universe idea one way or the other at this moment.

I believe I also said that.

Then please explain what "but that's not looking back in time to the beginning (BB)" in post #11 exactly means.

So the illustration of a bell shaped universe beginning with the BB is hopelessly flawed? I am not defending that , but Hawking seems impressed with that hypothesis in the above link.

Since we don't even know if the universe has any shape to speak off, it's totally unwarranted. Anything derived from such things is pure speculation.

But If I understand the thrust of your argument, the universe would have to be a 3D sphere with the BB at its center. Am I correct in that?

I have stated multiple times in this thread now that we don't even know if the universe is finite. I have clearly stated in this very thread in a direct response to you that the universe does not have a center; heck, that's the sole content of my first post in this thread! You either have a very, very, very bad memory, or you are being intellectually dishonest.

How could one take a slice of time (as illustrated in the link) from a 3 D sphere with the BB at its center?

(Irrelevant.)

The universe as illustrated is a bell shaped configuration starting from a singularity and expanding which allows for a universal slice of "now" at every point in time.

Yes, but the universe doesn't have a bell shape (as far as we know); it's just illustrated as such, but that part of the illustration doesn't (directly) reflect reality.

But how could you make a slice of time from a 3 D sphere or measure it at all?

(Irrelevant.)

Can you reconcile 14 billion years of time since the beginning, with 92 billion light years in diameter?

This has already been mentioned in this thread before: universal expansion. Space grows. In fact, the very illustration that we as discussing clearly shows this. How can you not understand this?

 

[Write4U]

It's you who's suggesting that, not me. You claim that illustration is an accurate depiction of the universe. You claim it's possible to take a position outside of spacetime (thus introducing a new space-like dimension).

Iqualified it as an an abstract POV
[/quote]I've so far given responses to all your incoherent statements as well, so... But seriously, I already indicated in my post #28 something went wrong. (I see what happened now; the textbox in my browser keeps jumping my cursor around; not sure why. The text was mangled.) Let me coherentify it:
"is clearly deriving properties of the universe from that picture, indicating you take the picture to be truth."[/quote] No, it was an illustration which seemed to exite Hawking as a new hypothesis.

Because we can only see ~14 billion years in the past? Because that's the lifetime of the universe one derives from the CMB? This is basic GR!

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?

For the record, Write4U seems to quote me as saying: "Age may only be a number, but when it comes to the age of the universe, it's a pretty important one. According to research, the universe is approximately 13.8 billion years old.", but I never said that.

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).

I have not formed any opinion on this bouncing universe idea one way or the other at this moment.

Nor have I, The illustration in direct response to the OP question which asked if we could see past the center (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?) and was not the center of a 3 D sphere but the beginning of our universe. 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.

Then please explain what "but that's not looking back in time to the beginning (BB)" in post #11 exactly means.

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.

Since we don't even know if the universe has any shape to speak off, it's totally unwarranted. Anything derived from such things is pure speculation.

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.

I have stated multiple times in this thread now that we don't even know if the universe is finite. I have clearly stated in this very thread in a direct response to you that the universe does not have a center; heck, that's the sole content of my first post in this thread! You either have a very, very, very bad memory, or you are being intellectually dishonest.

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?

Yes, but the universe doesn't have a bell shape (as far as we know); it's just illustrated as such, but that part of the illustration doesn't (directly) reflect reality.

That's an assumption on your part.
I find it an interesting idea.

This has already been mentioned in this thread before: universal expansion. Space grows. In fact, the very illustration that we as discussing clearly shows this. How can you not understand this?

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.

 

[Seattle]

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?
That's an assumption on your part.

No one has said that the universe is a sphere. We living in 3 dimensions so it's not a stretch to say that the universe is not 2D

No one is approximating the universe at 92 billion light years across. That's the visible universe. The universe can be infinite or not and that still holds true.

 

[Write4U]

questions:
a) If a slice of time creates a 2 D circular plane of the universe, would it not create a 2 D flat suface, like a 2 D still picture without depth where 3 D objects could not exist? Would we not see a few points of objects closest to us, or would we se anything at all? It takes infinite small moments of time for us to observe anything.
b)If time stopped at this very instant would the world disappear, photons would stop moving and we would be unable to observe anything. All events from our past would disappear because the light emitted or reflected would also stop.

c) In regard to a possible infinite universe (a universal Hilbert Hotel); That seems an unlikely scenario to me.
In the Hilbert hotel we can just add rooms, but these rooms do not exist until we add them.
Thus if we have estimated a universe of a specific finite physical size, but expanding (adding size), there has to be an infinite permittive condition which allows for the universe to expand, no?

I believe that no one is claiming an already existing infinite universe, whereas the Hilbert Hotel is specifically identified as being infinite. I see a contradiction here. Can anyone explain how a measurable finite universe can be infinite to begin with?
I can imagine an infinite timeless permittive condition wherein the universe is expanding, but this condition cannot be called the universe because the universe is a limited spac/time configuration which is expanding.

 

[Write4U]

No one has said that the universe is a sphere. We living in 3 dimensions so it's not a stretch to say that the universe is 3D.

I agree but that is only due to time which allows us to see old things. If time stopped we'd be living on a 2 D plane, no?

No one is approximating the universe at 92 billion light years across. That's the visible universe. The universe can be infinite or not and that still holds true.

 

[Write4U]

No one has said that the universe is a sphere. We living in 3 dimensions so it's not a stretch to say that the universe is not 2D

No one is approximating the universe at 92 billion light years across. That's the visible universe. The universe can be infinite or not and that still holds true.

Does this agree with this:

Because of the connection between distance and the speed of light, this means scientists can look at a region of space that lies 13.8 billion light-years away. Like a ship in the empty ocean, astronomers on Earth can turn their telescopes to peer 13.8 billion light-years in every direction, which puts Earth inside of an observable sphere with a radius of 13.8 billion light-years. The word "observable" is key; the sphere limits what scientists can see but not what is there.

But though the sphere appears almost 28 billion light-years in diameter, it is far larger. Scientists know that the universe is expanding. Thus, while scientists might see a spot that lay 13.8 billion light-years from Earth at the time of the Big Bang, the universe has continued to expand over its lifetime. If inflation occurred at a constant rate through the life of the universe, that same spot is 46 billion light-years away today, making the diameter of the observable universe a sphere around 92 billion light-years

The shape of the universe
The size of the universe depends a great deal on its shape. Scientists have predicted the possibility that the universe might be closed like a sphere, infinite and negatively curved like a saddle, or flat and infinite.

A finite universe has a finite size that can be measured; this would be the case in a closed spherical universe. But an infinite universe has no size by definition.

According to NASA, scientists know that the universe is flat with only about a 0.4 percent margin of error (as of 2013). And that could change our understanding of just how big the universe is.

"This suggests that the universe is infinite in extent; however, since the universe has a finite age, we can only observe a finite volume of the universe," NASA says on their website. "All we can truly conclude is that the universe is much larger than the volume we can directly observe."

https://www.space.com/24073-how-big-is-the-universe.html

Ok, but can we then speak of the universe as physical spacetime? And how can an infinite universe have an age? Would it not by definition be timeless?

 

[Xelasnave.1947]

I find this discussion most interesting and although perhaps a little off topic I ask a question.

The start was a singularity which seems to imply something very small and from that I assume it must be finite so does this not mean that no matter how much inflation grew the universe it can never grow to infinite and irrespective of its incomprehensible size can only be finite?
Alex

 

[Seattle]

Does this agree with this:
https://www.space.com/24073-how-big-is-the-universe.html

Ok, but can we then speak of the universe as physical spacetime? And how can an infinite universe have an age? Would it not by definition be timeless?

To answer your first question..."yes", what I wrote agrees with what you posted below.

All I addressed was the observable universe. You seemed to be having a problem with that and confusing it with the entire universe.

I'm not personally all that interested in the shape of the universe as it is difficult to visualize. I've read about the 3 options and how they would play out. I'm not particularly interested in thinking about what infinite actually would entail either. It's a difficult concept that is hard to swallow.

I'll leave that to others. I was just addressing the concept of the visible universe. That applies regardless of the rest of what you are discussing.

How can an infinite universe have age? It depends I guess but what we are discussing is the age of the universe since the Big Bang. Being infinite doesn't necessarily imply that it has always existed but it doesn't preclude that either.

Again, if we are trying to discuss those things for which there is evidence then we are in the realm of the Big Bang. The rest is just conjecture with no evidence at this point.

 

[Write4U]

To answer your first question..."yes", what I wrote agrees with what you posted below.

All I addressed was the observable universe. You seemed to be having a problem with that and confusing it with the entire universe.

I'm not personally all that interested in the shape of the universe as it is difficult to visualize. I've read about the 3 options and how they would play out. I'm not particularly interested in thinking about what infinite actually would entail either. It's a difficult concept that is hard to swallow.

I'll leave that to others. I was just addressing the concept of the visible universe. That applies regardless of the rest of what you are discussing.

I agree with your post that all we can actually see is spherical, but embedded within the actual universe.

 

[Write4U]

I find this discussion most interesting and although perhaps a little off topic I ask a question.

The start was a singularity which seems to imply something very small and from that I assume it must be finite so does this not mean that no matter how much inflation grew the universe it can never grow to infinite and irrespective of its incomprehensible size can only be finite?
Alex

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.