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

Discussion in 'Alternative Theories' started by nebel, Dec 8, 2017.

  1. Write4U Valued Senior Member

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    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.
    There is a difference between water waves and the Universal Pilot Wave.
    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.
     
    Last edited: Dec 8, 2017
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  3. Write4U Valued Senior Member

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    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.
     
    Last edited: Dec 8, 2017
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  5. Xelasnave.1947 Valued Senior Member

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    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
     
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  7. Seattle Valued Senior Member

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    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.
     
  8. Xelasnave.1947 Valued Senior Member

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

    Alex
     
  9. nebel Valued Senior Member

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    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.
     
  10. Seattle Valued Senior Member

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    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.
     
  11. NotEinstein Valued Senior Member

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    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?
     
  12. Write4U Valued Senior Member

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    So you are saying there are 5 dimensions? I just called it an illustration from an abstract POV.
    Does that incoherent statement warrant a response?
    Then how can we claim it is ~14 billion years old? There seems to be a contradiction in terms here.
    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 believe I also said that.
    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?
    Can you reconcile 14 billion years of time since the beginning, with 92 billion light years in diameter?
     
  13. Seattle Valued Senior Member

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    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.
     
  14. NotEinstein Valued Senior Member

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    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).

    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."

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

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

    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 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.

    (Irrelevant.)

    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.

    (Irrelevant.)

    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?
     
  15. Write4U Valued Senior Member

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    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.
    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?

    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).
    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.
    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.
    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.
    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.
    I find it an interesting idea.
    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.
     
  16. Seattle Valued Senior Member

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    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.
     
    Last edited: Dec 10, 2017
  17. Write4U Valued Senior Member

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    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.
     
  18. Write4U Valued Senior Member

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    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?

     
  19. Write4U Valued Senior Member

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    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?
     
  20. Xelasnave.1947 Valued Senior Member

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    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
     
  21. Seattle Valued Senior Member

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    3,493
    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.
     
  22. Write4U Valued Senior Member

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    I agree with your post that all we can actually see is spherical, but embedded within the actual universe.
     
  23. Write4U Valued Senior Member

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    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.
     
    Last edited: Dec 10, 2017

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