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Striving for Time Travel

  1. May 25, 2010 #1
    Please excuse the far-fetched nature of this thread. I only ask of your opinions.
    If you do not like these kinds of threads, then don't read it!

    In your opinion, would it be worth the effort to strive to build a time machine, so that you could go to the future where the medical field has advanced enough to live indefinitely, (or at least for millions of years?) This includes the physics, financial aid, the actual building of it, and then whatever is done on the "other side" to increase longevity.

    I am 18 so I calculate I have optimistically 72 years left of life. Of course I wouldn't be by myself in striving for this, (if I did indeed decide to try) as I am sure there are plenty of others trying to build or design a time machine.

    If I knew that it would not work, (after much effort,) then I would probably go on to study biomedical engineering or biochemistry, so that I could replace body parts with artificial parts, (and however the heck it would be possible to preserve the brain itself.) The problem with it is that I am more interested in physics, and I see that striving to build a time machine would be a possible method of living longer through physics study.

    I hate to ask "what should I do" questions, but many people on these forums know a lot more physics than I do.

  2. jcsd
  3. May 25, 2010 #2


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    Hi Jonny,

    That's not how it works here at the PF. Overly-speculative discussions are not permitted. It's not a matter of not reading threads that violate the PF rules.

    Now having said that, I'd like to address your question. No, it would not be a good investment of your time to focus on trying to come up with a working time machine, especially one that you could use to move your body through time.

    It sounds like you are a bright student, and you are thinkiing about your future (and the future of others). You might look into the field of Medical Physics or Biomedical Engineering. You may find some interesting and valuable things that you can do if you pursue degrees in those fields.
  4. May 25, 2010 #3

    Thank you, I appreciate the response.

    I will consider Medical Physics and Biomedical Engineering as well.
  5. Jun 6, 2010 #4
    thanks barak,

    Who will come?
  6. Jun 6, 2010 #5
    Your assumption of a better medical field in the future is probably flawed logic. If anything the medical field will be worse 50 years from now imo.
  7. Jun 6, 2010 #6

    Ivan Seeking

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    There is a nice review of some proposals, the problems, and the possibilities, for real time machines, in a book called The Future of Spacetime; copyright 2002. It is a collection of essays from some of the world's leading physicists. It doesn't seem likely that time travel of the sort you describe could ever be possible, but it can't be conclusively ruled out yet either. Most likely, if it is possible, the energy required would far exceed anything that might be managed, in practical terms, for a very long time, if ever. So it doesn't seem like a good career bet.

    There was a physicist who thought he had figured a way to make a "time telephone" [effectively] that would allow a connection between the present and the future. But as is usually the case when we hear about exotic claims like this, he had made some errors in his calculations. In the end it appeared that his model was fundamentally flawed.

    I believe that it is generally agreed that, based on the current understanding of General Relativity, any time machine that could conceivably work, could only go back in time to the moment the machine is first started, but no further. So even the most optimistic appraisals suggest that we are locked out of the past in this sense; the past that preceeds time travel. But, we can go to the future now. All that is needed is to travel at speeds near the speed of light, relative to the earth. In principle, one can leap into the future as far as one desires. It is all a matter of the energy required to make the trip - to power your rocket. Unfortunately, it takes a very large amount of energy to make a very short leap. To make a leap of a few seconds earth time, over a twenty-four hour trip [your time], would take far more than NASA has ever managed.
    Last edited: Jun 6, 2010
  8. Jun 6, 2010 #7
    Could you explain what makes you think so?
  9. Jun 6, 2010 #8
    Have you seen the movie idiocracy? It's not a joke.

    Also to Ivan all you need to send a messege into the future is dig a hole toss some treasure into it and then place a map of the location at some location to be found later... Travel into the future is for the most part retarded it would be like making the choice to go thru de-evolution.
  10. Jun 6, 2010 #9

    Ivan Seeking

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    Really? :uhh: Obviously that would not be point. What would be more interesting would be to get information from the future. But that possibility poses all sorts of problems and creates a few paradoxes.

    What you are saying makes no sense.
  11. Jun 6, 2010 #10
    Well ya of course time travel into the past is impossible the only reason why you might say it's possible is because it's fun to talk/think about.
  12. Jun 6, 2010 #11
    Could you please briefly explain why?
  13. Jun 6, 2010 #12
    Ya please explain how this machine is able to violate causality?
  14. Jun 6, 2010 #13


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    It is believed that you can not travel back before the time machine was functioning.

    Lets say you could start a functioning time machine today and left it on. Someone a hundred years from now sends a message back to you. You now have a portal to the future.

    At least that was Mallett's theory, but it did not work.
  15. Jun 6, 2010 #14


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    Time travel to the past is not impossible. Its just not achievable. There is a difference there :biggrin:

    I am referring to worm holes and super fast space ships of course.
  16. Jun 7, 2010 #15

    Ivan Seeking

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    That is a philosophical question. In short, we don't know the answer. Some argue this how we know a time machine can't work. On the other end of the spectrum, some Many Worlds proponents claim that the paradox is moot because the timeline splits. Anyway, if you really want to know what the best minds have to say about it, read the book. No one here will do better than Hawking, Thorne, Novikov, Ferris, Lightman, and Price.

    There is a really fun thought experiment mentioned in this regard. It uses a billiards table with a time machine attached to one pocket. Can a ball be made to interfere with itself so that it both enters the pocket, and doesn't? You might be surprised at the answer suggested. Apparently there is a rigorous derivation that addresses this thought experiment.
    Last edited: Jun 7, 2010
  17. Jun 7, 2010 #16

    Ivan Seeking

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    Obviously this is all highly theoretical at best. As stated, even if possible, it may never be practical. However...

    People talk about creating artificial wormholes [in the distant future]. IIRC, travel back in time beyond the point in time that the wormhole was created, is impossible. If a natural wormhole was found and could be used, then presumably the same rule would apply, but the wormhole may be very old, which might suggest that the age of the wormhole allows one to travel to the distant past. So in that circumstance, perhaps there is an exception. But since we don't know of any naturally occuring wormholes, the point is moot unless we find one and have the technology to use it. There is also the notion of circumnavigating a black hole, but I don't remember if or how that technique is limited in time. However, in real terms, most designs are implicity limited, as described. If there are exceptions to the rule, then, perhaps, as you stated, practical limitations make the point academic.

    The main point is that many if not all real concepts for time machines have this fundamental limit: You are limited in time by the history of the machine. I thought this applied to all time machine concepts, but I may be wrong. In fact it has been long enough since I followed this stuff that I will go back to my original suggestion: Just read the book. :biggrin:
    Last edited: Jun 7, 2010
  18. Jun 7, 2010 #17
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