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Time Travel 1191

Almost Anonymous writes "Ronald Mallett, a physicist at the University of Connecticut, believes he knows how to build a time machine - an actual device that could send something or someone from the future to the past, or vice versa. He plans to have a working mockup this fall. For all those doubters, he assures people that "I'm not a nut"." Uh-huh.
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Time Travel

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  • by D_Gr8_BoB ( 136268 ) on Sunday April 07, 2002 @03:43AM (#3297939)
    Say someone in the future develops a time machine using some newly discovered way of exploiting a loophole in the laws of physics. Such a machine would almost certainly be used to travel into the past. And yet in the present, no time travelers from the future have been observed.

    I have much more faith in the possibility that a time machine is impossible to construct than the possibility that all time travelers in the future will be so careful that no one will notice them.
  • by Cogos ( 310453 ) on Sunday April 07, 2002 @03:53AM (#3298001)

    According to the quote in the article there is a big flaw in the plan"If his idea pans out, won't there be a host of potential paradoxes, such as time travelers killing their parents and making it impossible for them to exist? No, he says, explaining that those travelers would continue to exist in a ''parallel universe.''

    In other words, anyone or anything sent into the past create some sort of parallel universe. Which means we will never see any evidence that the time machine works. At best he'll be able to create an effect where you toss something in and it disappears. Sounds to me like a great way to get rid of garbage but a less than ideal way to travel.

    Of course there should also be plenty of parallel universes where stray neutrons, lab rats, and grad students will appear out of no where. THOSE timelines will have proof time travel works. But unless that happens I'm not getting into any so called time machine.

  • Re:hey... (Score:2, Insightful)

    by sinserve ( 455889 ) on Sunday April 07, 2002 @04:08AM (#3298069)
    Wow, tommorows news flash

    "Slashdot reader discovers the benefits of proof reading .. Called "nut" by slashdot editors".

  • by Kwirq ( 43822 ) on Sunday April 07, 2002 @04:11AM (#3298082) Homepage
    Actually, you wouldn't be so much going back in time to another universe, as you would be spawning a new fork in the tree of all these diverging parallel universe. The "change" in this branch of universes, of course, would be your additional presence.

    This whole interpretation of time travel and the many worlds theory was used quite skillfully in the novel The Proteus Operation [] by James. P. Hogan in which an american team travels back (from a world where Nazi Germany controls most of the world) to foil Hitler's development of the A-bomb.

  • Re:hey... (Score:3, Insightful)

    by tftp ( 111690 ) on Sunday April 07, 2002 @04:13AM (#3298087) Homepage
    Some scientific theories dealing with time travel have the restriction that apparently you can't go back in time to before the invention of the time machine. I don't understand why, so don't ask me.

    If you could go back in time before the time machine has been built, then you could build it using your knowledge, and then the original condition of "no time machine before such and such date" would be invalid. Therefore, the theory that you could go back is proven to be incorrect.

    In other words, for any machine construction date D the actual construction date can be D-1 or earlier, going back forever. That's probably why you can't go back before the invention date - remaining on the same timeline, at least.

  • by vlad_petric ( 94134 ) on Sunday April 07, 2002 @04:16AM (#3298091) Homepage
    Assuming that an object can travel backwards in time, it does it relative to a reference systems. What would that reference system be ? The Sun ? The center of the galaxy ? The center of the universe ? I definitely don't like the idea of being teleported into dark, empty space.

    Well, it could be the machine, but that means you can only go back to the moment when the machine started funtioning. So I don't really buy the father thing. (April 1st joke, I guess)


  • Re:Well... (Score:2, Insightful)

    by ROBOKATZ ( 211768 ) on Sunday April 07, 2002 @04:23AM (#3298125)
    Maybe we nuke ourselves out of existence before we get it working.
  • by Anonymous Coward on Sunday April 07, 2002 @04:50AM (#3298200)
    As Richard Feynman said, "Scientific imagination is imagination in a straitjacket." The other kind may seem more fun, but accomplishes nothing because it doesn't work.

    Now if a kid wants to engage in time travel, I would discourage it. Nothing we know that I know about has any chance of doing that. Ditto for anti-gravity. You have to learn to accept the straitjacket.

    But if the kid wants to understand time travel, then encourage that. From the mystery of Time's arrow, to anti-particles being regular particles going backwards in time, to strange geometries in General Relativity where it is possible (but which require multiple stars worth of material moving in rather unnatural ways to accomplish), there is lots to engage the mind. But you can't lose track of the gap between what we think we know, what we think might be possible, and what we know doesn't work. Without that you might as well be a witch doctor invoking the spirits for all of the effect you are going to have...
  • Forward only (Score:1, Insightful)

    by Anonymous Coward on Sunday April 07, 2002 @05:12AM (#3298239)
    If forward time travel becomes possible, then no one would need a refridgerator.
  • by HanzoSan ( 251665 ) on Sunday April 07, 2002 @05:21AM (#3298259) Homepage Journal
    Its a known fact based on super stringn theory, that there are other dimensions, up to 11 others, according to M theory, and string theory, and the newest theories in physics, Time travel if it is possible in terms of what we understand from physics, would create a fork in reality where the time traveler would go through the fork in the road and join the future, we'd continue on our own fork in the road and go to our future, this person who time traveled would simply be missing from our reality and placed into the other. It would be a transfer of matter from one reality to the next, like if you create a fork in a pipe and you send a ball through one of the forks, the ball can either split up and be in both forks at once (which i doubt) or the ball can go into one fork or the other.

    If the ball goes in both forks at once then they'd be able to return back to our time and tell us what happened, if the ball leaves our reality, it can never return back.

  • Re:Respected? (Score:1, Insightful)

    by Anonymous Coward on Sunday April 07, 2002 @05:46AM (#3298324)
    That being said, I believe time travel *will* be invented/discovered *some time*,

    Then where are the time travellers from the future? ;)

  • by GlassUser ( 190787 ) <slashdot&glassuser,net> on Sunday April 07, 2002 @10:31AM (#3298916) Homepage Journal
    How do you know this isn't already the ultimate slice of universe, with everyone's time travel already factored?
  • by red_gnom ( 545555 ) on Sunday April 07, 2002 @02:12PM (#3299613)
    Then, how is he going to see two neutron particles at our universe if it will apear at some mirror universe.

    Well, he does not understand his own theories.

  • by Jay L ( 74152 ) <jay+slash&jay,fm> on Sunday April 07, 2002 @02:39PM (#3299746) Homepage
    As we all know, Slashdot is mostly about a bunch of geeks arguing about topics they don't really know about but claim to be experts on. (And yes, I include myself in that group for most values of "topic".)

    This article is about time travel. None of us are in the field. None of us have done it. None of us have seen anyone else do it. Few, if any, of us have read a single front-to-back thesis on which the proto-science is based, or anything else more detailed than SciAm. Yet the thread now has SEVEN HUNDRED COMMENTS, filled with the usual "I hate to introduce facts into the conversation" and "No, no, you just don't get how it works!"

    It doesn't get any better than this.
  • Re:Ill explain (Score:2, Insightful)

    by $uperjay ( 263648 ) <jstorrie.ualberta@ca> on Sunday April 07, 2002 @02:56PM (#3299812) Homepage
    Still a bit off. First, the distinction needs to be made between a going-to-the-past time machine or a going-to-the-future time machine. The latter is easier to make: either travel near the speed of light so time moves more slowly for you, or just get yourself cryogenically frozen. Since you're moving down the timestream, there are no problems with you ending up down a different branch than that which you started on.

    A traveling-to-the-past machine, however, is quite different. You don't just pick another possible reality and hop to it - that's not a time machine at all, and you've probably been watching too much Sliders. Instead you trace back along the path you took through time-space. You could, conceivably, end up following a different branch from your destination. However, since you'd be following your own path through time-space backwards, you'd be affected by the trip as well, growing younger, losing memories, et cetera. The current model of time travel dictates you could only go back until the time at which your time-machine became operational, as well. And, of course, since your consciousness would have be rewound, so to speak, you'd have effectively ceased to exist. Probably the only use for it would be repeatedly hopping back until you found a branch of the timestream that you liked (or one in which your time machine was destroyed before you could go time-traveling again!). You wouldn't remember anything at all, though, so the distinction between reliving a part of your life and suicide would be a very fuzzy one. In effect, you'd have snuffed out your own existence in favour of creating another branch on the tree of time-space.

  • by norton_I ( 64015 ) <> on Sunday April 07, 2002 @03:10PM (#3299876)
    I don't think this person is necessarily on crack, though I am skeptical he is going to achieve conclusive evidence of time travel. I would very much like to read a paper on the theory of how this thing is supposed to work.

    However, the page you linked to looks to be pretty much a crackpot. Basically, his claim is that since it doesn't make any sense (to him) for time to be relative, it can't be. This is primarily based on an attemt to "reason" if it can be called that, about relatavistic physics based on non relatavistic assumtions.

    The big givaway for people who don't understand enough physics to realize this is that he starts off his rant by resorting to namecalling at people who believed things he can't understand and therefore must be impossible, without any evidence other than his lack of understanding.

    Take for instance, Godel. He claims, "He is known for his incompleteness theorem, the most obfuscated, non-scientific, chicken feather voodoo nonsense ever penned by a member of the human species... The only thing Gödel proved, in my opinion, was the incompleteness of his frontal lobe."

    He never actually even says what he thinks is wrong with Godel's incompleteness theorom, which is probably because there are legions of mathematicians who would dearly love for it to be wrong, but have been unable to find any problem with it. This is the mark of a crackpot. If he can restate his objections in a form more convincing than "this obviously doesn't make any sense" and restrict himself to science and leave the namecalling out of it, I might be inclinded to read it and figure out if it made sense or not.

Thufir's a Harkonnen now.