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Is Timetravel possible?

  1. May 26, 2008 #1
    The question, very short cut: Is timetravel (as we are getting it showed in movies) possible, "yes", "no" or "dunno" (science doesn't know)? How can antimatter in terms of the SM be interpreted as matter moving backwards through time? Is there any possible better understandable depiction to this?
  2. jcsd
  3. May 26, 2008 #2
    Time travel into the future is a possible idea due to the time dilation from Einstein's Theory of Relativity.

    There are supposed ways of getting around time travel to the past, like creating parallel universes each time it's done or whatnot. But I wouldn't count on that idea too much, haha.
  4. May 27, 2008 #3
    Wormholes may be one exact solution of general relativity, known as an Einstein-Rosen bridge. Whether they will prove practical in the future depends a lot on whether they can be kept from closing upon the traveler.
  5. May 27, 2008 #4
    Thank you Loren Booda.
  6. May 27, 2008 #5
    Is Timetravel possible?


    The question, very short cut: Is timetravel (as we are getting it showed in movies) possible, "yes", "no" or "dunno" (science doesn't know)? How can antimatter in terms of the SM be interpreted as matter moving backwards through time? Is there any possible better understandable depiction to this?

    Anyway (and take it with a smile; it's a joke) yes timetravel as we are getting it showed in movies or more generally everywhere around us is possible : because our own life is a timetravel. And to realize that, you don't need any wormhole or complicated science.
  7. May 27, 2008 #6
    Experimentally, localised distortion of both space and time have been observed by a massive rotating object causing such distortions around it's edge peripheral. This phenomenon is called "frame-dragging"
    Any object placed within that peripheral region will experience the effect.
    However, this is early science, and much has to be learned to utilize and/or modify this effect to a useful level.
  8. May 27, 2008 #7
    I've heard about all those theoretical aspects, what I concern tho (sorry, I didn't say that) is wether going back in time, changing the "timeline" and returning to the current time is possible.

    Could this even be possible? If I'd "transfer" mass into another time, it would "pop up" there and hurt the law of conservation of mass and energy, right? If I'd experience disorted time do to dilatation, what would it look like?
    Last edited: May 27, 2008
  9. May 27, 2008 #8
    Theoretically, yes it is possible. Einstein theorized that space and time are one single thing and must be referred to as space-time. Gravity is simply the curvature of space-time. The very fabric of space-time is bent by massive objects. If we could somehow bend space-time far enough at two points we could travel through this bent space or hole, known as a wormhole, and travel to places in time. Physics allows us to do this because of our vantage point. Looking at a clock inside a wormhole will read a different time than if you were to look at one outside the wormhole, giving you totally different perspectives, as if you were going to a totally new time. This of course is entirely theoretical at this point and hasn't been made by man... yet.
  10. May 28, 2008 #9
    Okay, but what is the solution to this famous paradoxon then? If I really bend time so I can move back to an earlier point in time and all other dimensions are retained, and I prevent my earlier self from doing what I did - will this affect my very self me again?
    Or should time travel rather be seen as a travel to an alternate dimension where time is shifted so my original dimension stays unafffected beside my disappearing from it? If so: Wouldn't the "travel" to another dimension contradict mass-energy conservation?

    Furthermore, if we assume that "dimension travel" is actually possible and - at the same time - presume that there are at least ten different dimensions (this is something which emerged from SST, isn't it? Am I allowed to bring this in?) which suppose an infinite numbers of alter-realities, wouldn't that imply that there is at least ONE alter-reality, where people already invented a device which enables them to timetravel and should have visited US?

    My knowledge on this is really limited, as you can see. I'm sorry if the above sounds absolutly stupid and unprofessional :-(
  11. May 28, 2008 #10
    none of that sounds stupid at all. those paradox are complexing questions theoretical physisits ask all the time. the answer is no one knows. many people belive that time travel will never happen based upon those reasons. so i guess we will just have to wait and see what happnes, if it ever does. and yes the interdimensional travel is one theory out now, but again, no one knows for sure exactly.
  12. May 28, 2008 #11


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    This was recently discussed here:https://www.physicsforums.com/showthread.php?p=1743502#post1743502.
    One would need to think more carefully about what "mass-energy conservation" means in this instance.

    Why do you need to invoke extra spatial dimensions for this argument? I would imagine that in this case there are some precise laws governing where you can actually travel to; for example, a commonly held belief is that one cannot travel back to a time before the time machine was created. Does this hold for the one that you are travelling into?

    As an aside, I think this thread is drifting further and further away from Physics!
  13. May 28, 2008 #12
    i think it is possible with much more research.
  14. May 28, 2008 #13
    The school of thought is still out on this one. There are a lot of possible developments coming from the new Hadron Collider in Cern is not fully operational yet but the price tag for this instrument is over 6 billion dollars, a capital B for billion, and that’s a lot of money. To further answer your question is time travel possible, the answer so far is that no one really knows for sure. Some people say no way and others say yes. Some people say the Hadron Collider is capable of producing a Einstein Rosen Bridge to the past. The problem is that if it does create the bridge it will only be the size of an atom. To small to step through, so a lot of experimental work needs to be done. I went to the CERN page a copied the below to give you some understanding of how this machine will work.

    (LHC) is a gigantic scientific instrument near Geneva, where it spans the border between Switzerland and France about 100 m underground. It is a particle accelerator used by physicists to study the smallest known particles – the fundamental building blocks of all things. It will revolutionise our understanding, from the miniscule world deep within atoms to the vastness of the Universe. Two beams of subatomic particles called 'hadrons' – either protons or lead ions – will travel in opposite directions inside the circular accelerator, gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams head-on at very high energy. Teams of physicists from around the world will analyse the particles created in the collisions using special detectors in a number of experiments dedicated to the LHC. There are many theories as to what will result from these collisions, but what's for sure is that a brave new world of physics will emerge from the new accelerator, as knowledge in particle physics goes on to describe the workings of the Universe. For decades, the Standard Model of particle physics has served physicists well as a means of understanding the fundamental laws of Nature, but it does not tell the whole story. Only experimental data using the higher energies reached by the LHC can push knowledge forward, challenging those who seek confirmation of established knowledge, and those who dare to dream beyond the paradigm.
  15. May 28, 2008 #14
    I've pondered this question all my life and attempts at an answer have been quite futile. I don't think we can ever say one way or the other. But, the reason I'm leaning towards the negative is as follows. These points are worth considering.

    Causality - cause and effect as we know it would be turned on its head. If a person causes an event, then goes back in time to undo it, what happens? What if a person meets his past self or future self if they go forward. If I bring an object with me to the future, say a wristwatch, and then encounter that same watch in the future, consider the following. Suppose I were to destroy my watch from the past. What would happen to the future version? Also, how can the same wath from 2 different time frames mutually co-exist. Where did the extra mas/energy come from? It's tough to get around that.

    Also, there are some practical limitations that would make time travel extremely difficult. Let's use the motion picture trilogy "Back To The Future" as a reference. The earth rotates on its axis, and revolves around the sun, which rotates on its axis, and revolves around the galaxy, which moves etc. My house is not in the same location it was a minute ago, let alone 30 years ago. When Marty went back 30 yars in time, the earth was in a different position in the solar system, and the galaxy, etc. How did the time machine compensate for all of that? It would be a pretty remarkable feat!

    I doubt it.
    Last edited: May 28, 2008
  16. May 28, 2008 #15
    Hi rockerdoctor...

    Nice to read your reply and very well written I might add. I for one do not know the answer. Like you I have pondered this very same question is time travel possible. I initially said no way but as I kept reading a unique set of words kept popping up again and again and here is what I am reading...

    A growing number of physicists are convinced that the thing we call ‘the universe’ — namely space, with all the matter and energy it contains — is not the whole of reality. According to quantum theory — the deepest theory known to physics — our universe is only a tiny facet of a larger multiverse, a highly structured continuum containing many universes.

    I could easily write some deep explanation with scientific clarity but to answer your hypothesis of cause and effect and tell you that the laws that govern our universe can not be broken, but what if when you go back in time and make a change to the time line the change does not effect your future but rather a alternate future in the multiversity.

    Everything in our universe — including you and me, every atom and every galaxy — has counterparts in these other universes. Some counterparts are in the same places as they are in our universe, while others are in different places. Some have different shapes, or are arranged in different ways; some are so different that they are not worth calling counterparts. There are even universes in which a given object in our universe has no counterpart

    On large scales, universes obey the laws of classical physics, and so each behaves as though the others were not there. But on microscopic scales, quantum mechanics becomes dominant and the universes are far from independent. Universes that are very alike are close together in the multiversity and affect each other strongly, though only in subtle, indirect ways — a phenomenon known as quantum interference.

    Without quantum interference, electrons would spiral into atomic nuclei, destroying every atom literally in a flash. Solid matter would be unstable, and the phenomena of biological evolution and human thought would be impossible. And as I shall explain, it is quantum interference that provides our evidence for the existence of the multiversity.

    Through interference, its counterparts in other universes can affect each particle in our universe. What we see as a single subatomic particle is really a sprawling trans-universe structure, spanning a large region of the multiversity. Although we cannot see the parts of this structure that are outside our universe, we can infer their presence from the results of experiments.

    As I said scientists are going to experiment with high speed partials at CERN so the rules have not been written yet, we have no unified theory yet. We just do not know what is possible. I for one hope for time travel, can you just imagine knocking on your families door in say 1941 would they believe you came from the future or just call the cops saying you are a madman. No one would ever believe you. I remember an old saying.... we have met the aliens and they are us…. Have a great day Big Walt
  17. May 28, 2008 #16
    This message is the answer to cabraham not rockerdoctor...very sorry for the name mix up...........
  18. Jun 4, 2008 #17

    Aren't we already travelling into the future but at a very slow pace?
  19. Jun 4, 2008 #18
    I did not read the entire thread. I want to point out the quantum instability of any time-travel device (I did not see it mentionned before).

    Any time-travel device used to open some sort of "bridge" between a spacetime point and another one in its future is plagued with a quantum instability. Quantum fluctuations, for instance in the electromagnetic field, will amplify themselves quite like in a laser and have your device blow up.

    As Kip Thorne showed, the only way to avoid this is to have negative energy density making the "structure" of your wormhole. This seems to me like a no-go theorem, because negative energy density, as of our current understanding of physics, is an oxymoron.
  20. Jun 4, 2008 #19
    Is Time travel possible?

    I'd say --No
  21. Jun 4, 2008 #20
    I'm sorry, I don't think it's possible
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