if time machine does exist, are we able to travel back before big bang happens.

Discussion in 'Physics' started by Werapon Pat, May 15, 2018.

  1. Werapon Pat

    Thread Starter Member

    Jan 14, 2018
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    I wonder, does time really exist, before big bang happens.
    which one happens first? time or big bang?
     
  2. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    If a sphere was a cube, would it have corners?
     
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  3. crutschow

    Expert

    Mar 14, 2008
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    If there is nothing before the big bang, how can there be time?
    Time is a sequence of events.
    Nothing to sequence, no time.
     
  4. dl324

    AAC Fanatic!

    Mar 30, 2015
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    It depends on how you view the big bang. Was the big bang the beginning of everything or was it the result of a previous big bang that contracted and caused another big bang?
     
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  5. -live wire-

    Active Member

    Dec 22, 2017
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    I mean if there is infinite time and a very large amount of matter and if time travel is possible than it would happen at some point in time. And there had to have been time before the big bang. Just not necessarily anything happening except the POS changing characteristics.
     
  6. jpanhalt

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    Jan 18, 2008
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  7. OBW0549

    Distinguished Member

    Mar 2, 2015
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    Were there politicians before the Big Bang? If not, I want to go there...
     
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  8. profbuxton

    Member

    Feb 21, 2014
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    How can time travel be possible? There is , in my opinion, no way to travel into the past or future, regardless of what Dr. Who says.
    We(the whole universe) can only exist in this instant. You cannot go back or forward even one heartbeat in time.
    All objects in the universe travel relative to each other and I see no way of enabling any object to be in more than one instant of time.
    If one imagines a timeline, objects are at some point on this timeline and one point only. If one could look along this timeline there would be nothing in the future and nothing in the past.
     
  9. joeyd999

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    Jun 6, 2011
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    Not even Langoliers?
     
  10. nsaspook

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    It might be possible with "superdeterminism" where 'time' is just a 3D illusion to us mere mortals but that also means no 'free will' because all future events are already set in stone with fine tuning of initial conditions by a 'God'.

    http://www.informationphilosopher.com/freedom/superdeterminism.html
    http://backreaction.blogspot.co.at/2013/10/testing-conspiracy-theories.html
    https://blogs.scientificamerican.co...interview-with-nobelist-gerard-e28099t-hooft/
    https://arxiv.org/pdf/quant-ph/0510090.pdf
     
  11. Glenn Holland

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    Dec 26, 2014
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  12. BR-549

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    Sep 22, 2013
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    How long was it before the big bang? An instant or an eternity?
     
  13. Glenn Holland

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    Dec 26, 2014
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    Since the exact nature of the object that existed prior to the Big Bang has not been determined, the time scale for its existence cannot be determined either. Some theories portray the object as a monstrous and massive object like a black hole that somehow became so unstable that it exploded with relativistic speed.

    So the next three questions are:

    [1] How the object came to existence in the first place.
    [2] Why was it stable (if it was ever stable at all) and for what amount of time.
    [3] Then why it suddenly became unstable and exploded.
     
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  14. DickCappels

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    Aug 21, 2008
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    Time travel is absolitely possible. We are all doing it right now...and now...
     
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  15. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    As you know, today is yesterdays tomorrow.

    Bertus
     
  16. bogosort

    Active Member

    Sep 24, 2011
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    It doesn't work that way. The Big Bang is a prediction of general relativity (under certain assumptions), and in GR space and time are not distinct, absolute things. When we want to calculate distances and velocities and such, we have to do it on a 4D spacetime with curved geometry.

    Once that framework is in place, every event in the universe is associated with a point on a world line, which represents the trajectory of an object through spacetime. The Big Bang is the prediction that all world lines converge at some finite time in the past. This point of convergence is a spacetime singularity -- since there are no more world lines "behind" this point, the past is literally undefined.

    In other words, we can't use GR to predict the Big Bang and then try to use the same theory to predict what happened "before" the Big Bang. A similar situation arises with black holes. Certain solutions of the field equations predict such drastic spacetime curvature that, within a certain radius (the event horizon), all future world lines converge. If we want to know what happens inside black holes, or what happened before the Big Bang, we need a stronger theory than GR, almost certainly a quantum gravity theory.
     
  17. SLK001

    Senior Member

    Nov 29, 2011
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    Yes, you can. I have gone there many times - not much there, tho, just a small, bight dot a long distance away.
     
  18. Glenn Holland

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    Dec 26, 2014
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    That is more a mathematical construct than a practical explanation of what happened when (and after) the Big Bang occurred. If another Big Bang occurred about light year from the earth, we would see a Hell of a lot more happening than equations flying out of it.
     
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  19. bogosort

    Active Member

    Sep 24, 2011
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    Without the mathematical construct, there is no Big Bang theory. It's not possible to decouple the two in any meaningful way.

    The language of physics is mathematics. While it's easy to lose sight of this fact for phenomena that happen at ordinary human scales, where we've developed an intuition that corresponds pretty well to the math, the situation is entirely different at scales far outside of our daily experience. Here, intuition utterly fails us and the only thing we can rely on is the math. This is true of both the quantum scale and the cosmological scale, and it is certainly true for the birth of the universe!

    It is what it is. The universe's complexity is such that, without the equations, practical explanations are -- at best -- meaningless. More often, they're just simply wrong.
     
  20. oz93666

    Senior Member

    Sep 7, 2010
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    Time travel has been going on for nearly 60 years , secretly by the US government ...Search "Montauk Project" and "Al Bielek"

    As for BB ... an unproven theory.
     
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