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Time Travel 1191

Posted by michael
from the gladly-pay-you-tuesday-for-a-hamburger-today dept.
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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  • Umm... (Score:4, Interesting)

    by ByteHog (247706) <[moc.gohetyb] [ta] [sirhc]> on Sunday April 07, 2002 @03:37AM (#3297915) Homepage
    Define "Working Mockup" :)
  • Poignant. (Score:5, Interesting)

    by Lemmy Caution (8378) on Sunday April 07, 2002 @03:41AM (#3297923) Homepage
    Whatever the viability of his claim, his motives are poignant - he wants to go back in time and warn his father, who died of cancer when he was 10, of the danger of cigarettes.

    I have no idea how physicists approach the question of the creation of a contrafactual timeline which removes its own motive for existing (if his father lived, then he wouldn't create the time machine, and thus etc. etc.) But I think this is more interesting, if tragic, as a story of a man who still misses his father than as a viable line of research.

  • Irony (Score:2, Interesting)

    by ROBOKATZ (211768) on Sunday April 07, 2002 @03:48AM (#3297969)
    The inspiration for working on time travel came from his secret desire to go back in time and warn his father to quit smoking, as his father died when he was 10 years old.

    So say he builds his time machine, goes back in time, and saves his father. Now he did that in a "parallel universe" (according to the article), and so now in this universe he doesn't invent time travel because his father is alive.

    In conclusion: this man will not invent time travel, because if he does, it must only happen in a parallel universe.

  • Hmm... (Score:2, Interesting)

    by Gangis (310282) on Sunday April 07, 2002 @03:49AM (#3297978) Journal
    As far as I know, it's possible to go FORWARD in time, since the faster you are to the speed of light, the slower the time around you. I once read that they took an atomic clock on one of the Concorde supersonic planes, and another one on the ground, and there was a time dilation of 0.0003 (or something like that) nanoseconds. If you could find a way to go even 99.999% the speed of light, you'd age only a few days while the sun's entering it's Red Giant phase. Or something like that.
  • by Anonymous DWord (466154) on Sunday April 07, 2002 @03:52AM (#3297996) Homepage
    For most of his career, however, Mallett kept secret that his desire for time travel had drawn him to become a physicist. It wasn't until a few years ago, when he began researching a book on the topic, that he arrived at his idea of how to build a time machine.

    Seems to me that's a great reason to become a physicist. Imagine what kind of creativity we could produce if the reply to something like that was "Cool! Here's some books to help you," rather than "You're crazy. That can't happen, so go do something else."
  • by wickidpisa (41827) on Sunday April 07, 2002 @03:59AM (#3298032) Homepage
    C'mon, any 15-year-old who daydreamed in math class knows that we will NEVER be able to send people back in time, for the simple reason that we'd have met them already.

    That is not true at all. We haven't met any time travelers because you can not send anything back to before the machine is built. To go back 10 years you need to run a time machine for at least 10 years. All that is happening is that it opens a wormhole to itself, you can not just open one to any time in the past. (This might sound like sci-fi BS, but this comes from actual scientists)
  • by David Jao (2759) <djao@dominia.org> on Sunday April 07, 2002 @04:02AM (#3298041) Homepage
    There are a number of ways to resolve this apparent paradox. While I'm not claiming that any of these are for real, like all speculations they are not easily dismissed either.

    First of all I assume by "someone in the future" you mean a human on earth. In this case, one of the simplest ways to avoid the future time travelers paradox is to posit that a backwards time travel of N years must physically be accompanied by a spatial displacement of more than N light years. That way, nobody who travels back in time can interact with anything affecting their own past, since they can't interact outside of their light cone.

    Another way out of the time travel paradox is to adopt the "parallel universes" viewpoint put forth in the article, and provide some mechanism for explaining why we always stay in the one universe out of these that has not seen time travelers.

    Finally, if by someone in the future you mean aliens from somewhere other than earth, then this problem is also easy to resolve: since we have not seen any aliens at all (roswell notwithstanding), it's unreasonable to expect to find alien time travelers.

  • Food for thought (Score:3, Interesting)

    by BlueJay465 (216717) on Sunday April 07, 2002 @04:06AM (#3298061)
    Time travel is not a new concept, obviously. Time machines have been invented and successfully used for some time now. However, the reason we haven't seen any successful results of them, is that time protects itself from tampering.

    If Professor A creates a time machine, and uses it to travel back to the past to alter a certain event, say preventing JFK from getting shot. He may effect the timeline, but he will create a branch at the same time. He will continue along that branch and reality forever.

    The rest of us on the main trunk will never see that effect that professor A had on the past, since history has already been written for us. Professor A has been lost forever since he will be living in the history he has created.

    You could go back in time, but you will never be able to return to THIS reality. That would be the paradox.
  • by wickidpisa (41827) on Sunday April 07, 2002 @04:09AM (#3298076) Homepage
    Time travel isn't that big a deal, I mean come on, when you can get a book on How To Build a Time Machine [barnesandnoble.com] at your local bookstore why are people so amazed at this? The book is real, and it is a serious book (it is not to be confused with the children's book with the same title published previously). The author explains that we know how to travel through time, it is just really expensive at this point. It is a budgetry problem, not a science problem.
  • by Cogos (310453) on Sunday April 07, 2002 @04:10AM (#3298078)
    That at least is covered by the reference to parallel timelines. From our timeline, we'll call it Alpha, time travel would seem like a quick trip to oblivion. A time traveller in Alpha steps into the circle of light or whatever and dissapears. No one from timeline Alpha will ever see him or her again. Of course in timeline Beta someone just appeared out of nowhere and they have plenty of reason to believe time travel is possible. Except that from their point of view their time machine will work the same way. You step in and disappear.

    In fact thinking about it if this view of time travel is true and workable it would almost seem like a wacked out cult. A person appears and claims to be from the future. They either have schematics for a time machine or they inspire development of one. (We'll ignore they likely outcome that any visitor from the future is locked up with all the Thorazine they'll ever want for the purpose of this discussion). When the machine is built it can't be proven to work. The best evidence any timeline will ever have is one visitor. Would you trust the word of a possible nut ball and step into something that makes matter disappear? I think only borderline psychotics would be nervy enough to do so. Which suggests that the time traveller would be kind of kooky to begin with.
  • yes and no (Score:2, Interesting)

    by Inferno666 (568675) on Sunday April 07, 2002 @04:17AM (#3298097)
    Yes time travel into the future is possible, by aproaching the speed of light. However once at the speed of light time stops. This leads to the theory that if you go past the speed of light you will actually arrive at your destination before you left (negative velocities) and that is basically travelling back in time. Breaching the speed of light is the obsticle to be passed by in this instance. So yes you can go forward in time, but you can also go backwards in time, in theory... but since no one has done either it's all theory anyway. As for the why haven't people come back in time to right the wrongs, you can't predict what changing the past could do. Think about it, if you change the past so that something bad never happend, then in the future the bad thing never happend, so there's no point in going back and changing it, but if you don't go back and change it then the past isn't changed. For that reason it's probably illegal to time travel without certain licensing and training to stay inconspicuous. Maybe it never happens at all, or maybe the people inventing time machines realised what type of a weapon they are unleashing on the world and stopped trying to make their machine.
  • Re:hey... (Score:5, Interesting)

    by blackwizard (62282) on Sunday April 07, 2002 @04:17AM (#3298098)
    They talk briefly in the article about 'time paradoxes' -- he claims the time travelers would continue to exists in a 'parallel universe'. I would speculate that he can't do what you suggest because the instant someone actually uses the thing to go backwards in time, they create a parallel universe. So if he did that, he would be giving it to himself in some other universe -- not this one. Ironically, it would also kind of defeat the purpose of going back in time to warn his father about smoking -- he would still die in the timeline that he normally exists in, although his dad might live longer in the parallel universe created by his time travel. If you believe this theory, then it's also interesting to note that the only 'real' universe is the one that nobody has time traveled to! And if you believe that, then you might have a hard time testing your time machine -- what happens to that matter that was in the current universe but is now in some other 'parallel' universe? There are still a lot of problems with this. =)
  • by anshil (302405) on Sunday April 07, 2002 @04:24AM (#3298128) Homepage
    Travelling into the future is no big deal, only technical. theoretically just jump to near light speed a short while, jump back and thousend years will have passed on earth.

    However travelling into the past _is_ a big deal, as it questions a lot of physical fundamentals. What about energy conservation? Would the energy of the matter vanish out of the present? Would it pop out in the past. The particle of course already existed in the past, will exist then twice there? As I've now in the past two times the enery of the particle, have I created new energy?

    Simply take a machine that transports a neuron back a second in time, 2 Neurons will exist then in a second before, put the time machine will still run there "a second time", so 3 Neuron will exist a second before, a second later the time machine will again send a neuron back a secnd. 4 Neurons will exist, so on and so on.

    Is the ener
  • Re:hey... (Score:5, Interesting)

    by Kintanon (65528) on Sunday April 07, 2002 @04:26AM (#3298134) Homepage Journal
    Some people (me included) hold with the theory that evrey possible permutation of the universe exists simultaneously. So each possible situation exists in some paralel universe/timestream. So if you developed a way to skip between Universes/timestreams at will then you could theoretically visit a place/time where things were just like they are now, except all of the flors are color shifted a few degrees on the visual spectrum.>:)
    Or what have you. Kind of a Sliders type of universe setup.

    Kintanon
  • by NanoGator (522640) on Sunday April 07, 2002 @04:36AM (#3298161) Homepage Journal
    "The second particle would be the first one visiting itself from the future."

    I see two problems with this:

    1.) What would keep the particle appearing in the future from appearing in the same spot? Seems like they'd try to occupy the same space..

    2.) how will they know it's the same particle? Guage it's spin maybe?

    Im concerned that the experiment could produce positive results, but not positively. Kind of like that fusion bubbles thing not too long ago.

    Here's a question though: Is it possible this could be a new way to harness energy? Imagine reclaiming energy from the past...
  • by murphyslawyer (534449) on Sunday April 07, 2002 @04:42AM (#3298180) Homepage
    Light does travel different speeds through different substances. The speed of light we are always talking about is speed in a vacuum, and outside of gravitational influences (gravity bends light). If I remember right, the speed of light in a fiber-optic cable is roughly .7 the speed in a vacuum.


    On a slightly different note, the speed of information can be faster than light, such as when transmitting a signal over a conducting wire. The electrons themselves move on the order of 1 m/s, but they push all the others in front of them along. Imagine a frictionless tube of sand a billion miles long. Push the sand on one end in with a plunger, and as soon as you do, sand falls out the other regardless of the length of the tube. Imagine just using a really long stick. Weird, huh?

  • Re:Poignant. (Score:2, Interesting)

    by seanadams.com (463190) on Sunday April 07, 2002 @04:56AM (#3298210) Homepage
    he wants to go back in time and warn his father, who died of cancer when he was 10, of the danger of cigarettes.

    He died at the age of 33!! I've never heard of smoking killing someone at such an age. As a 23 yr old smoker myself, that scares the shit out of me. I could be half way dead already.

    I'm getting good at quitting though - done it 20 times already today!
  • Ill explain (Score:5, Interesting)

    by HanzoSan (251665) on Sunday April 07, 2002 @05:14AM (#3298244) Homepage Journal
    When you go to the past, this is assuming time travel to the past is actually possible, it modifies the future, the future is no longer the same. You are now in a totally diffrent dimension, a diffrent reality, one which you created when you entered the time machine.

    Time travel is something our minds do on a daily basis, you can imagine future events, sometimes you are right and sometimes you are wrong, traveling into the future allows you to travel into a POSSIBLE future, but no future is THE absolute future,

    Time is not mapped, its dynamic, it works like this, everything that can happening, is happening if not in this reality in another.

    Its more like sliders than likee the time machine movie, you travel through realities, or mirror universes, according to current theory, its believed theres infinite mirror worlds

    A time machine actually isnt a time machine in that sense, its a machine which allows you to go into any reality you want, or create your own reality by modifying the past.

    We all create our own reality anyway, the diffrence is with a time machine, YOU have an advantage, you can not only imagine a new reality but literally control the future by modifying the past.

    Its like gambling but cheating.

    A time machine allows you to essentially cheat.

    The reason we dont see anyone coming from the future is, when you travel to the future, the past changes, you can never go back to the original past, if you do go back to the past its a new past thats a mirror of the original one.

    I'm convinced anyone who will time travel into the future will never return, basically they'll vanish forever and all will vanish with them

    Anyone who travels to the past will vanish forever from our reality

    basically time travel is a one way trip.
  • by GMontag451 (230904) on Sunday April 07, 2002 @05:16AM (#3298247) Homepage
    First of all, he was talking about the particle going back into the past. He talked about a second neutron appearing. This would be the one from the future that was sent into its past (which would be the present [god i hate talking about time travel]).

    What would probably happen is:

    1. You have the first neutron.
    2. A second one appears, being the future neutron.
    3. The first one disappears, having gone into the past to become the second neutron.
    4. Only the second one remains, which is now indistinguishable from the first one, except for the fact that it is now slightly older than it should be.
  • This is actually not that new of an idea. Larry Niven (sci-fi novelist) wrote a short story called "All The Myriad Ways" about something like this. It basically was about a detective researching suicides in people that travel parallel dimensions. It also has the notion that each second infinitely many parallel universes appear as each possible outcome of the present.

    The real kicker is about how when the dimension travellers get home. When they leave, a little point is set on their display as to which universe to return to. As time passes, the universes multiply, and that single point becomes a band of points--because their universe has already been going on without them. The "widening of the bands" apparently causes these guys to get depressed and off themselves.

    This begs the question (with regards to those timelines appearing out of nowhere) about whether a time traveller will be able to direct which universe they could head towards. There was another book, Novelty (can't seem to find the author), that had an idea that you couldn't travel contrafactually (so universes containing many time travellers just got wierder and wierder), so it was possible for a set of parallel universes to exist where people, were their own grandfather, but not a universe where someone killed their grandfather (or if they did, they got kinda stuck in that universe because they couldn't go back, or something like that). Although, the book didn't explore the idea too thoroughly.

    Anyways, seeing how nature would sort out this kind of hubris would be damn interesting.

  • by OblongPlatypus (233746) on Sunday April 07, 2002 @06:35AM (#3298443)
    A much simpler explanation for why he hasn't gone back in time to tell himself: If he's able to succeed on his own (that is, without interference from himself), he wouldn't need to. If he isn't, he would never be able to.
  • Re:Poignant. (Score:2, Interesting)

    by Bongo (13261) on Sunday April 07, 2002 @07:35AM (#3298562)

    I have no idea how physicists approach the question of the creation of a contrafactual timeline which removes its own motive for existing

    That's an easy one to answer. There is no such thing as Time.

    Time is just a concept that's useful to us.

    It's easy to check this for yourself. Have you noticed that whatever time it is, it's always the present?

    The present moment is all that there is. Eternity is the timeless now.

    Even memories are experienced in the present. We're living an ever changing present moment.

    Oh, and there's no Space either.

  • by ReadParse (38517) <john AT funnycow DOT com> on Sunday April 07, 2002 @09:54AM (#3298823) Homepage
    I have what I think amounts to an interesting theory disproving any possibility of time travel. Perhaps somebody else has already brought this up (not necessarily on Slashdot), but here goes.

    I believe that, in this case, "absence of evidence is evidence of absence". In other words, the fact that we don't already know about time travel is evidence that time travel will never be possible. This gets confusing quickly, but if time travel ever becomes possible, somebody will surely travel to what is our past. While early attempts might be "covert" (a la "Back to the Future") to prevent altering the future, this could only be successful for so long. Even if attempts continued to be made to keep it a secret, somebody at some point would have either told somebody that they met in the past or there would have been rumors or something.

    But all references that we hear to the possibility of time travel are based in the future, such as this story about a guy who's "going to do it". Of course, we all know he will fail, because otherwise, we would have already known of his success. At the very least, if he was to ever be successful, we would not be living in a world where he was trying to travel in time to save his dad from cigarettes, but rather in a world where his dad had been saved from cigarettes by his son.

    In fact, if time travel were to ever be successful, we would have always known about it, and the quest for time travel would not exist.

    It gets more interesting and more confusing as you think about it...

    RP
  • Re:More information (Score:2, Interesting)

    by MontyP (26575) on Sunday April 07, 2002 @10:08AM (#3298858)
    Yes, This is common belief that I have heard and read before. Logically, if you have a device that is capable of sending you back in time, you would need an entry point in the point of time you are traveling to. If no device is capable of time travel in this past point in time, then there would be no time travel and therefore impossible. There are many arguments against the possibility of time travel, one of which intrigues me. That is that if matter cannot be created or destroyed, how can you travel back into time without adding more matter to that point in space and time.
  • Um, no (Score:1, Interesting)

    by Anonymous Coward on Sunday April 07, 2002 @10:23AM (#3298896)
    Would you believe someone if they told you they had come from the future? Think Back to the Future again... Doc didn't believe Marty was from the future without a specific piece of information that no one could know without time travel. Thus, the time traveller would have to have the specific intent of becoming known to the people of the past(not out of the realm of possibility). The time traveller would also need sufficient information to make such a display to a large number of people. Then he still might not be accepted, as the people he convinces could fall prey to the same "crazy nut" treatment that he would start out with.

    Maybe time travel does/will work for this guy, but he either decides not to change his past for moral/ethical/headache reasons, or doesn't get a chance to do so within his lifetime.

    I don't believe that just because we don't see evidence of something that that is in fact evidence that that something doesn't exist. If you're looking for a certain kind of evidence, and that's the wrong kind of evidence, you're not gonna have much luck. Likewise if you don't know that a particular occurance is definate evidence of that thing.

    Some said that if this contraption works, all will succeed in doing is whirling objects back or forward in time, out into the middle of space where the Earth once was, or will be. I say: "Hey! that's not a bad thing! It's the new travel craze! Just pop in the time machine, and zip around to the other side of the world hours before you left! Just remember to pack a parachute, eh?
  • by imnillusion (571769) on Sunday April 07, 2002 @10:34AM (#3298918)
    I continue to be amazed at people's gullability in regards to the idea of time travel. It is a most universal desire.

    It is absolutely impossible.

    The reason I say this so strongly is that I know that it's so. Think about this for a moment. Time is a concept. One cannot travel through a concept.

    Time is what people use to the explain the phenomenon of rearrangement of matter. Things are in a different configuration so it is a different 'time'. The only difference from one 'time' to another is the position of all of the matter and energy in the entire universe. To revisit another 'time' would be to observe the precise configuration of all matter in a previous state. Now check you thermodynamics pocket guide, and the relativity manuals you were issued and immagine the energy required to restore every particle and quark to a previous state simultaneously without using any energy from the universe; you can't siphon your own gas tank! And this is further complicated by the theoretical presense of the observer in the data set. Adding 165lbs of matter to the total massof the universe may not be a good thing.

    Now recreating the position and vectors for all matter and energy is one problem, but the database to store the coordinate and vector data for all those objects for an infinitely resolved universe is going to HAVE to be quick!

    Simply stated. time does not exist. There is only one instance of existance and it's now.

  • by alienorifice (126419) on Sunday April 07, 2002 @10:40AM (#3298929)
    Traveling to the future is easier than traveling backwards. The Mir astronauts traveling at 17,500 MPH have already traveled 1/50 sec into the future on their missions.
  • Re:Respected? (Score:2, Interesting)

    by Jhan (542783) on Sunday April 07, 2002 @11:34AM (#3299055) Homepage

    The time machine variations I have seen (ie. massive rotating cylinder, toroid black hole and a few more) only allow you to travel back in time to the moment the machine was set up - and only forward until the time it is dismantled.

    It all has to do with creating closed time-like loops, loosely a path through space that allows you to return to the same position at an earlier time. Want to go back further, go around another time. Want to go forward, loop in the other direction. In other words, the 'machine' itself does not move through time. Only you do, by following specific paths around it.

    Most time machine conecpts involves extremely dense objects (think neutron star matter or singularities) moving at sizeable fractions of the speed of light. I wonder exactly how much power those lasers of his generate?!

    On the subject of forking universes, paradoxes etc., my understanding (IANAP, IAAP-groupie) is that there can be only one time line, which must be consistent. When you apply quantum mechanics to a system with closed time-like loops, the probability wave functions sum to zero for any events which would be paradoxical. So, you can't kill gramps. Think 12 Monkeys.

    Oh, and some believe (about 50/50 among those I have spoken to) that the probability waves will sum to infinity for all non-paradoxical events, creating infinite energy densities and blowing up any time machine even as it forms. Hopefully not taking the city/planet/universe with it.

  • by Kalabajoui (232671) on Sunday April 07, 2002 @12:55PM (#3299332)
    Not delivered by me, because I lack the physics background to do do the topic justice. However, I've copied an URL below, to a page that does an excellent job of debunking time travel, multiple universes, and other dubious claims of modern physics. Personally, I found the information contained within the page compelling, and when I take physics as one of my required college courses, it will be interesting to see if it remains so.

    http://home1.gte.net/res02khr/crackpots/notorious. htm
  • by Anonymous Coward on Sunday April 07, 2002 @02:05PM (#3299581)
    Mallett's homepage [uconn.edu]
  • by Anonymous Coward on Sunday April 07, 2002 @02:27PM (#3299681)
    Beyond this researcher's current experiment, assuming that we someday might be able to transport a human, this form of travel sounds pretty dangerous. Wouldn't there be a lot of travelers floating in space (considering that the earth would move between the times they were sent and received) or trapped in solid rock or other nastiness? I'm reminded of the good old teleport spell.

    Perhaps, as someone mentioned before, the travel destination would always be the current location of the machine and one would be limited to times when the machine was functioning.
  • by bobdole369 (267463) <{moc.liamg} {ta} {963elodbob}> on Sunday April 07, 2002 @03:46PM (#3300006) Homepage
    OK, say you manage to travel through time, via a device located on earth. When you exit, time has passed, or (the opposite) and suddenly you end up in space, alone and unprotected. Why? simply because the earth is NOT in the same place you left it. The revolution of the earth around the sun has occured, and the rotation of the earth around its axis has occured, and the movement of our sun through the galaxy has occured, and the movement of our galaxy has occured, and so on. Therefore any time machine must also be a translocation machine like a transporter in star trek speak. Also it must compute all these variables to place you back at the correct place.
  • by ErikBaard (452757) on Sunday April 07, 2002 @09:34PM (#3301293)
    Hi All -

    I have spoken with Dr. Mallett a few times and trade emails with him. I'm writing a science fiction story based on his ideas, and including him a straight journalism article.

    Some comments and jokes about time paradoxes were raised in postings, so I'll hit a few points. Mallet believes that time portals work only from the time they are first opened. If you open a portal this Wednesday, you can receive a visitor from Thursday, but that person can't rush back to Tuesday or Monday.

    The only "out" is that perhaps a person could go to a parallel past if there are myraid universes in a multiverse. Then you might get a visitor from Thursday to start your week Monday morning, but because you have no influence on that timeline, I wouldn't bank on it. Then there are issues of conservation of matter and energy to consider, right down to photons even if a person never passes through the portal.

    Anyway, Mallett's not a nut. He's a theoretical physicist. Hard to tell them apart, of course, but I'm grateful when new ideas pop up from either.

    Erik

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