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. NotEinstein Valued Senior Member

    Do you mean: "from an observer infinitely far away, time seems to freeze at the event horizon of a black hole"?

    What does this have to do with "reach[ing] back toward the bing Bang"?

    It does not. The line simply becomes longer (assuming the expansion is uniform).

    The universe is almost perfectly flat, and it has indeed flattened out over time.
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  3. nebel Valued Senior Member

    how could a singularity near the big bang be flat, without curvature?

    sorry,used wrong word. The black hole mass is stuck on the point on the time radius when it formed, it is out of this world, and the direction of the time line points back into the past i.e. BB.

    That is the description of a spiral. A line that becomes flatter with time, length.
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  5. NotEinstein Valued Senior Member

    I meant the universe is almost perfectly flat today.

    No, it's not. Obviously it's still around at later times; black holes don't vanish from reality the moment they form; that would be silly!

    That is pure conjecture. And it's probably either false, or untestable (it might be impossible for that information to travel outside of the event horizon).

    It's also the description of an logarithm, or a square root function. Or of the positive branch of y=1/x.
    Additionally, how is the behavior of the spacetime curvature over time related to the "timeline of a normal entity"?
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  7. nebel Valued Senior Member

    What I have read, the mass that formed that hole is gone, but the effect lingers, The effect is seen in the dimple, the tear of the skin, the gradients of the expanding sphere. That hole has stopped on its time point of formation in the radial timeline. The elongated trace of the black hole reaches back in time. All we can see is the effect now, the mass has been left behind in time, closer to the origin. or?
  8. NotEinstein Valued Senior Member

    The matter is (most likely) gone, but not the mass. A black hole is defined by its mass (and angular momentum, and charge): no mass means no black hole.

    A black hole is not necessarily a tear.

    What does that mean?

    No, it hasn't. There's a black hole at the center of our galaxy; it's been observed over the course of many years. Obviously that black hole is still "moving forward in time"; it hasn't "stopped on its time point of formation".

    In every way this statement is true, it's also true for any other particle and matter.

    No, the mass hasn't magically started traveling back in time. Where did you get that idea from?

    ...Are you still thinking about the balloon analogue, and visualizing a black hole as a dimple in its skin? And then concluding that since a dimple gets pushed inwards, it gets pushed back in time? And that a black hole will get pushed all the way to the origin? If so, you are extrapolating from a broken analogue: the balloon example gives non-sense results when doing this.
  9. nebel Valued Senior Member

    No, I meant that the black hole is stuck in time, on the radius, Time for the black hole has only stopped, not reversed. The universe has continued to expand outward from it, but the developing dimple stays that deep. Any variation in the movement through time, velocity, gravity would result in deforming the surface of the expanding sphere. different speeds through time, locally , shorten the radius there.
  10. NotEinstein Valued Senior Member

    Oh, I see. You mean that time gets frozen inside the black hole, while the universe continues onwards. The inside of the black hole gets "left behind".

    It's not entirely correct, as time passes by normally inside the event horizon; a particle inside the event horizon would notice nothing special about the passage of time.

    Black holes can evaporate through Hawking radiation, so the black hole can "catch up" with the rest of the universe.

    In the balloon analogue the radius of the balloon doesn't represent anything.
  11. nebel Valued Senior Member

    respectfully: I disagree. The inside of the expanding sphere model represents the time that we have passed through, the past, even if all events always happen in the skin, where the "now" has actually no thickness. The two dimensional surface of the expanding sphere is not all there is. The multiverse theories for example speak of more bubbles out there in different time "locations". Any traceable radius represents the time or world line of its point in the periphery since the beginning. That radius, is always at right angles to the tangent on the curved surface point.,- not unlike in our diagrams, where the time axis is normal to the space dimension.

    as to Hawking's radiation, way too high for me, but it does not mean that the deep well disappeared singularity is in a catch up race through time with us . The BH effects on the "skin", dimpling, tear,or tension, acceleration if you will, lingers on, even if the mass has disappeared from our realm, that skinny realm we call "now".
    disregard the cross out.
    ps: may be the Hawking radiation would smooth ou the effect of that steep gravity gradient, call it the ultimate skin rejuvenation treatment.
    Last edited: Dec 16, 2017
  12. NotEinstein Valued Senior Member

    And now model a big crunch universe in the same way. At some point, expansion stops and reverses. In the original interpretation, this is fine: we see the skin contracting, galaxies getting closer to each other, etc. In your interpretation, time itself would reverse. That's non-sense. In other words, the radius of the balloon analogue is not related to time.

    In the original interpretation, it is.

    Which is something not covered by the balloon analogue, as that's not its intent. In fact, multiverses are pure conjecture at this point, and not part of mainstream cosmology.

    (Have already been proven incorrect above.)

    Actually, it does. When the black hole evaporates completely, there is no dimple "stuck back in time" left. I.e., it must have caught up.

    Simply wrong. After evaporation, there is nothing left stuck at the black hole formation time or at any other time in the past.

    No, the Hawking radiation reduces the mass of the black hole. That's it. Any other effects are a result of that mass decrease.
  13. nebel Valued Senior Member

    You mis- interprets the model I have in mind. Time is inert, stationary, infinite, and all pervasive, fundamental. It is the occupant of time that advances, moves through time in our universe, away from the origin, time being normal to space dimensions. In a contracting universe, the future time would be limited, defined by the ever shortening radii that points on the periphery would follow. Ultimately vacate time.

    Is your view from inside the skin skewed your about the vast time that is out there., and that we experience only in the zero dimensional "now"
  14. NotEinstein Valued Senior Member

    I was going by your statement that: "Any traceable radius represents the time or world line of its point in the periphery since the beginning."

    What does "inert" mean in this context?

    What does "stationary" mean in this context?

    How do you know?

    (No disagreements there.)

    This is bad terminology; orthogonal would be slightly better. Also, I'm not sure that's true in GR, seeing as there's only the combined spacetime.

    Yes, and the balloon analogue handles such cases fine. If your model doesn't, then your model does not conform to the balloon analogue.

    Can you please rephrase that? The grammar is too broken for me daring any interpretation of what you meant to say.
  15. nebel Valued Senior Member

    Assuming that the departed mass of the black hole is in a deep well, with nearly vertical walls (gravity gradient), the change in
    mass effect would only propagate out of there at the speed of light, as demonstrated in the ligo receptions. so, no, the black hole will never creep back from the past. Though its effect on the ever expanding "skin" would diminish. Unless the BH theory has changed again.
  16. nebel Valued Senior Member

    By you dismissing any importance to the domain outside the expanding surface, it appears that you maintain the viewpoint of a flatlander. no criticism implied.
  17. NotEinstein Valued Senior Member

    That's not how spacetime works. The well in which the black hole resided is gone, and the "connection to the past" is severed. That observers further away aren't aware of that yet, is neither here nor there. In other words: if you claim the gravitational well is the connection to the past, that's wrong. If you claim that the observation from observers far far away is the connection to the past, it's (physically) meaningless. Which is it?

    But it did: it evaporated, and it's gone now.

    Not simply diminish: vanish.

    "Again"? And it's not "BH theory", it's the general theory of relativity.

    There is none in the balloon analogue. Only the skin represents anything.

    All right, shall we then start talking about a 4D hypersphere with a 3D surface, that expands into a 4D space? (The balloon analogue actually works better in such a case.)
  18. nebel Valued Senior Member

    Why complicate matters? In the expanding sphere model, Time is the domain that is at right angle to the 2D surface. The inside of the ball is the realm that the skin traveled through (past time) ( and it matters), the outside is the future time that the universe is expanding into. Messages are send into the future, but received from the past.
    Entities that are stuck in time because of max gravity, aka BHs, recede into the past, left behind by the expansion, creating deep gravity wells, Any news of them having evaporated will not reach the surface observers faster than "c" The merging of such vortices might trigger gravity tsunamis we can still detect across the billions of years, but an slow evaporation event?
    Reading Penrose, Kraus and others, time, the measure of duration, acceleration must predate the present universe, and the interior, exterior realm of the expanding sphere model is an appropriate representation of it. or?
  19. NotEinstein Valued Senior Member

    So reality is too complicated? And it's you that wanted to complicate matters; you said that I appear to maintain the viewpoint of a flatlander, so I discarded it fully, and now it's "complicated"? It appears it's you who wants to maintain the viewpoint of a flatlander!

    Yes, and this model breaks down fatally when you try to model a big crunch universe, as I already pointed out.

    But the gravitational wells aren't dimples on the surface. Gravitational wells do not reach back in time like that. A black hole is "stuck in the past" only when seen by an observer far far away. Locally, the black hole is simply in the present. A particle falling into the black hole doesn't travel into the past.

    What vortices?

    Are you referring to gravitational waves?

    The evaporation of a black hole is quite a violent event, if I remember correctly.

    What? Why must "time, the measure of duration, acceleration" "predate the present universe"? What does that even mean?

    No, it's not. It breaks down when trying to model a big crunch universe.
  20. nebel Valued Senior Member

    Any particle that reaches the event horizon, goes into the singularity, stops in time, does not continue with the rest of the universe in its journey into the future, from that moment it is gone. it is in the past of the lucky observer that is far enough away.
  21. nebel Valued Senior Member

    The vortices that were present in the merging of the black holes that LIGO observed, via gravitational waves. Black holes are famous for the extreme vortices, spewing xrays that they generate.
  22. NotEinstein Valued Senior Member

    Wrong; it's not known what happens to a particle when it reaches the singularity. For a proper description, a quantum theory of gravity is needed. Most certainly it doesn't "stop in time".

    It does; either the particle gets destroyed (in which case, it's wrong to word it like that), or the particle survives, and its mass keeps contributing to the black hole (in other words, it keeps existing in the present).

    Except that it obviously isn't, as I just pointed out.

    This however is true. (Although the far away observer never sees the particle reach the singularity.)

    Calling the ripples in spacetime during a black hole "vortices" is terrible wording, and perhaps even wrong.

    Do you mean accretion disks? If so, please call them by their name: accretion disks.

    Also, accretion disks can be present even if there isn't a black hole merger going on.
  23. nebel Valued Senior Member

    Examining my own flatlander view, we do not see the expanding perfect sphere model from our view point inside the "skin". we perceive more the shape of a fig perhaps, looking back (receiving information) along the surface of an ever smaller universe in the past. Only a super observeer independant of the speed of light could see the fully present model. The shorter radii of time of the smaller sized universe of the past evident. Like the annual tree rings, radius is the measure of time, now dead inside, only the cambium carrying life.
    Last edited: Dec 18, 2017

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