Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Couldn't the end of spacetime cause spacetime?

  1. Nov 27, 2004 #1
    Couldn't the end of spacetime cause spacetime? As in some sort of looping paradox keeping existence in existence.

    I just wanted to ask this question. It's probably wrong but I wanted to know what people think.
  2. jcsd
  3. Nov 27, 2004 #2
    can you explain your reasoning please. how could the end of spacetime cause spacetime...and are you talking about one universe or parallel universes?
  4. Nov 28, 2004 #3
    One universe. It's one of those paradoxical situations when the effect becomes the cause. What I'm suggesting is that because logically something can't come from nothing, some cataclysm in the present, past or future; be it the end of the universe or something else actually caused the big bang and therefore the universe. In other words the universe (assuming there is only one. This theory could be adapted for multiple but I choose not to at the moment) has always been here yet has a beginning. The beginning being caused paradoxically by it's end (or some cataclysm somewhere in time). If a piece of string was time. The begining of the string represents the beginning of time. Before this point you have no time, afterwards you do. But the piece of the string after this first point has always existed, but the existence of the string caused it's own existence.

    I realise this is probably nonesense. I can't really find the words to express it properly as of yet and so what above is probably contradictory.
  5. Dec 1, 2004 #4
    i am still confused how can the existance of the string cause its own existance?
  6. Dec 1, 2004 #5
    There is a possibility that a closed universe will go through an endless series of 'big bangs' and corresponding 'big crunches', in which spacetime does indeed expand to a maximum then contracts, dragging all matter inwards. Is this what you have in mind? Look into the "Robertson-Walker metric" with a closed universe and see if that's what you're thinking of. If so, current evidence suggests our universe is not closed; indeed the expansion is accelerating.
  7. Dec 9, 2004 #6
    Space Time cannot cease to exist because with that all matter must vanish. Energy created or destroyed and hence something cannot go into nothing.
  8. Dec 19, 2004 #7
    Why are you using the word 'paradoxically'?

  9. Dec 19, 2004 #8



    ALAN GUTH !!!!
  10. Dec 19, 2004 #9
    Actually, I was reading an article in Discover magazine, in which they discussed that since all matter was equal to all gravity in the universe that they canceled each other, so in fact, something could come from nothing.

    You could also get into the topic of anti-matter, where in random things, mainly neutrons, are created from nothing. Theoretically, albeit how rare it may seem, a person, dog, or plant could be created from nothing.
  11. Dec 20, 2004 #10
    I don't think this is what he is trying to say.
    I think it is more along the lines of, since there is a string, there is a beginning of a string. So there would have to be an end so that the string could exist. Kinda of like a line seg. is the only usuable form of a line.
  12. Dec 21, 2004 #11
    But you have to remember, that's only the way we, humans, think about it. That doesn't necessarily make it the way the universe itself works.
  13. Jan 25, 2005 #12
    time is a perception, so depending on where you are depends on how you view it.
  14. Jan 26, 2005 #13


    User Avatar
    Science Advisor
    Gold Member

    Hi J_desu101, welcome to PF! That's a difficult question. Anytime you talk about an 'end' to spacetime, you imply it had a 'beginning'. It is easier to talk about the beginning, since it appears to be a more recent event - and one we can nearly observe. It is a fun topic though... and no one can prove you wrong.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook