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Standing in nothingness before the Big Bang

  1. Nov 29, 2013 #1
    Hello, I have a question: let's say I was standing in nothingness before the Big Bang, then it happened! Would I first feel the pull of the gravity of the growing universe, then see it's light, and then feel the push of the gases. Or see the light, then the pull and the push because space hadn't gotten to me yet? Thanks for reading and answering my question.
     
    Last edited by a moderator: Jan 3, 2014
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  3. Nov 29, 2013 #2

    ShayanJ

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    Maybe someone's going to answer your question,I don't know...but I just feel I should clarify something.
    Even in well understood and well tested parts of modern physics,people can't imagine being in the middle of the system they're studying.And now you're asking us what would happen if we were standing at the middle of one of the most puzzling things in physics which is still an open theoretical question?!
     
  4. Nov 29, 2013 #3

    Nugatory

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    If you can stand in it, it's not "nothingness", it's perfectly ordinary empty space like we find outside the earth's atmosphere... So it didn't exist before the big bang. Thus, there's no good answer for your question as phrased... for roughly the same reason that I can't tell you what color the elephant in my living room is right now - the color of a non-existent elephant is not a meaningful concept.

    I know that's not a very satisfying answer, and I'm sorry, but it wasn't a very satisfying question either :smile:. You may want to try poking around in some of the threads in the "Cosmology" forum here, that will get you started on a line of thinking that will go somewhere.
     
  5. Nov 29, 2013 #4
    Thanks I know I can't stand in nothingness as a person. It was just a tumble of thought. I was listening to the fabric of the universe, and they use the visual of being on a river in a boat at high tide. When the moon suddenly disappeared they said we would notice the river receding before we saw the moon disappear. But that is in space, I thought things might change out of space in nothingness.
     
  6. Nov 29, 2013 #5

    ShayanJ

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    To Swimfit:
    About your comment on my post,Its OK to have strange thoughts,but the point is,when you enter physics,you should learn to think right and ask right...now people may tell this is going into boundaries which limits your creativity,blah blah blah...but there is always a law which induces some limit,its just possible to choose a broader limit than others'!
    And for learning how to think like a physicist,you should study about other physicists' ideas until you're able to give some ideas yourself and then you can try thinking like a physicist and by practice,someday,you will become a physicist.
     
  7. Nov 29, 2013 #6

    Nugatory

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    OK, that's the problem right there.....
     
  8. Nov 29, 2013 #7
    Ok the way I understood the expanding universe, is the the universe is expanding faster than the speed of light. So I thought one might feel the effects of the expanding universe before actually seeing it. But I guess it is something we just can't know since we can't be there.
     
  9. Nov 29, 2013 #8
    It is a book! The fabric of the universe. I was listening to while walking. Lol what is the color of your elephant in your living room? Any color you want it to be. It is imagination.
     
  10. Nov 29, 2013 #9
    To Shyan: I'm sorry I'm not trying to be a smart ***. I hope you didn't take it like that I was just asking a question. I just Thought someone would have an answer. But I know that there is no way to know something when we can't be there. In space things may act a certian way but outside the universe we just can't know. Thanks for taking the time for your answers.
     
  11. Nov 29, 2013 #10

    Nugatory

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    I know it's a book - it's just not a very good one :smile:

    Search this forum for "Brian Greene" and you'll see what mean.
     
  12. Nov 29, 2013 #11
    Thanks for reply. I will do the search.
     
  13. Nov 29, 2013 #12
    Ok let's see if I can ask this question in the right way. Let's say a star went super nova would a very sensitive machine notice the gravitational effects first or light first? I hope I asked this in the proper manner.
     
  14. Nov 29, 2013 #13

    marcus

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    The most common type of supernova is "core-collapse" type. In that case the gravitational collapse (and a huge release of neutrinos) happens well before the burst of light.

    1. If one had a gravitational wave detector sensitive enough to feel the ripple from the core collapse then that would arrive, and be felt, BEFORE the burst of visible light

    2. The neutrinos can be detected BEFORE the light. I believe this has actually happened. It would depend on how far away it was and on the speed the neutrinos were traveling. They travel ALMOST as fast as light, and they are generated in the core before the explosion shockwave has a chance to get out to the surface of the star and release visible light. Neutrinos pass effortlessly thru other matter so they can get out of the core and escape before the explosion shock, and they get a head start over the light.

    I'm not an expert but I'm pretty sure the answer to your question is yes.


    That is, both disturbances in geometry (aka grav. waves) AND light travel at the same speed, namely c.
    the collapse of the core of a massive star would probably cause some ripply disturbance in geometry and it happens before the release of visible light at the star surface.
    We humans may never get to the point of building a grav. wave detector sensitive enough to feel the collapse of the core of a star (I can't predict) but in principle it should be detectable and the slight geometrical ripple should, in principle, get here before the visible light.
     
    Last edited: Nov 29, 2013
  15. Nov 29, 2013 #14
    Marcus thank you so much for your answer! It was very informative. I tried asking the same question in let's say a more esoteric way which caused such and up roar, I think they knew very well what I was trying to ask but they were too busy tearing apart how I asked it. All they had to say is we don't know what happens outside the universe. And then tell me the answer to how it would happen within the universe as they understand it. Thanks again for taking the time to answer the question.
     
  16. Nov 29, 2013 #15

    marcus

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    You are most welcome! My pleasure.

    I'm glad you got some use from my response. I was thinking about your supernova question some more. You may have heard all you want about "which signal arrives here first?" and want to think about something else. But I'm curious about another aspect of that. Maybe someone else will see this and answer.

    Earlier I only discussed what happens with CORE COLLAPSE type supernovas (read Wikipedia about the mechanism: the core stops fusing and gets so dense and heavy it cannot support itself, there is a neutronstar or blackhole remnant).

    That's the majority type. But there is also an important type of supernova called Type 1A (again read Wikipedia, it starts with a binary star where the smaller partner has, say, fused up to carbon and is not massive enough to fuse beyond that to still heavier elements, so it dies and begins cooling, but then the larger partner goes giant and dumps crud on it, till it reaches critical mass and fuses all its carbon at once in a thermonuclear explosion.)

    Type 1A are wonderful supernovas because all of approximately the same intrinsic brightness determined by the critical mass for triggering a carbon fusion bomb . they leave no remnant! The whole star goes in the explosion. Not like core collapse, which usually leaves a neutron star remnant. It's very interesting. Do try the Wikipedia article on supernovas!

    My question would be, if anybody knows, which signal would arrive first? The geometry ripple, or the flash of light?

    The ripple of geometry would result from the disappearance of a star-sized mass. A whole lot of mass explodes to kingdom come and is removed from the picture. The larger partner of the binary pair now has nothing to orbit with, nothing pulling it. It suddenly takes off in some random direction. So spacetime geometry is radically disturbed. Clearly there will be ripples of geometry spreading out from that event! But isn't the flash of light SIMULTANEOUS with that, in this case?

    No,some people will say. The mechanisms that produce the visible light are more complex and take more time… The light will arrive later in this case as well. But I wonder.

    Well anyway, I'm curious about this. Maybe someone knowledgeable will respond.
     
  17. Nov 30, 2013 #16
    Thanks again Marcus! Very interesting I will read that article on supernovas . Yes i think your right that we would feel the ripple before we saw the light from the massive explosion. Like the example i mention earlier with the moon disappearing, we would feel or see the effect of the tide before seeing the light of the moon blicking out. They say gravitational ripple is instantanous at least that is the way i understood it. Of course I really don't know to really agree with you, but it seems like that is the order in which things would happen. So lets see if I have it right, if i was super sensitive and could feel all effects of every event I would feel the gravitational ripple first, then the light and then the force of the explosion. I'm glad that we are not that sensitive it would be overwhelming! But it would be interesting knowing all things as they happened. The way you discribe that super nova sounds like the way our sun will die. It will expand and envelope most of the planets and then explode. But will there be any rement left of our sun after? Another question! Lol thanks again for your answer.
     
  18. Nov 30, 2013 #17
    I read the article on supernovae and then read about our sun to answer my question about how our sun would die. Sound like it would expand and contract until it finally explodes and we are left with a white drawf star until it peters out to nothing. But will there be any mass left? Go back and reread! Lol
     
  19. Dec 1, 2013 #18

    Chalnoth

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    If our universe was born from another universe, then what you would see is a microscopic black hole popping into existence, then evaporating away into nothing almost instantaneously. If you could detect this microscopic black hole at all, you would have no way of knowing that it had resulted in the birth of a whole new universe.
     
  20. Dec 2, 2013 #19
    Chalnoth, thank you for your post: my main question was would we feel the effects of the gravity from the black hole and then the lack of it, and then the gravity of the new universe before we saw its light? Assuming our senses were infinite. Thanks again for your post . I've always wondered if our universe is just recycling, forming then finally shrinking back to a singularity, and then reforming. I guess we really will never really know for sure.
     
  21. Dec 2, 2013 #20
    That doesn't seem correct. What's the underlying explanation?
     
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