Can you travel Back through time?
965397
Travelling back in time is not allowed by einstein's theory of relativity...however if you can instantly teleport youself to some faraway star,say a 101 light years away, you might be able to catch einstein receiving his nobel prize!! as stated earlier, there is no master grandfather clock that is regularly ticking away the seconds..rather that rate is adjustable...but one may zip into the future..consider an example where you are on a space-ship at a speed of 0.99990 c that is going away from the earth and coming back..in your time frame say,it takes about twenty years..using lorentz transformations, the time for your to and fro motion is close to 450 years!!
56785
Yes, time travel is possible. :)\n\nIf you put a person in a rocket that can accelerate up to near light speeds on a round-about trip, when this guy comes back, he'd have aged much lesser than the guys who sent him. So he has travelled forwards in time.\n\nTravelling back in time is also possible. Oscilatting in time is possible. Time statis is also possible. All if we imagine a universe that has only a few elementary particles.\n\nHow? Well imagine a universe that has only a pendulum that swings back and forth. Now, we, as observers of this pendulum, can make the following observations, all different, and all "correct"\na. The pendulum is swinging back and forth as time advances\nb. The pendulum swings forth, then the direction of time reverses, and the pendulum goes back in time and swings back\nc. The pendulum is swinging forth and back as time retreats\n\nWhich of these is correct? We can't answer that question. So we can choose any one - it doesn't matter. These three are just different ways of looking at the phenomenon.\n\nYou may also want to read up about Feynman's diagrams
467276
In theory, the faster you move, the slower time advances for you. If you were to move at a speed approaching the speed of light, you could slow time enough that you could "travel" forward. It isn't really time travel, but whatever works...\n\nAs far as I know, traveling backwards definitely is not possible; time is a construct, something that only exists in one's mind. It is really a rate of change; the change can only occur in the positive direction, so traveling backwards is out.
519456
There are some strange solutions to Einsteins field equations which some theorists claim to offer the possibilty to travel backwards in time but these are pure hypothesis.\n\nFor one of these possibilties you would need a huge amount of "strange matter" which we yet even don't know what it is exactly, other of these hyothesis would allow to travel back in time, but not past the invetion of the thime machine, since this time machine is the "exit" on the other side of the "time tunnel".\n\nOther scientists say it will never be possible, for varios reasons, one of the most mentioned is the problem with causality (althogh there are again theories that that would't be a problem) another very funny one is by Stephen Hawking: There never will be time machines, becaus if it would we would see tourists from the future all the time.\n\nSo, seriuosly, don't expect to see a working time machine during your lifetime.
467849
I think that there is the theory that you could travel back in time, but it is really all Star Treckie.  I don't think there is any possibility of travelling back in time, no matter how fast you can go.
39733
umm...either i'd say that you must have copied the history channel, you are insane, or you perhaps found a way to go faster than the speed of light.\n\nsupposedly that would happen if you went that fast.  time slows the faster you go, and as you near the speed of light it virtually stands still, so if you go faster, then you start heading back in time.\n\ni doubt that you figured out a way though, so i'd go with you being insane if you truly believed that you could do visit ages past in person.
59515
Time travel is actually 100% possible.  You're time travelling right now, the problem is that you cannot control how to time travel.  \n\nIf you had enough fuel on a spaceship that could go at 99% the speed of light, the time on the spaceship is slowed down dramatically, this is called time dilation, which means your biological clock also slows down, slowing your aging process.  If you come back to Earth by travelling 60000 light-years, you're only 40 years older then, but the Earth and everyone on it is 60000 years older.\n\nTime travelling to the past is currently not possible.
989998
Theoretically possible. See: http://www.pbs.org/wgbh/nova/time/through.html
502465
There is no such thing as time travel, it's a physical impossibility. The reason we haven't had any visitors from the future is because time travel simply cannot occur.
412986
according to einstein's theory of relativity, if you are able to travel at a speed faster than that of light then you will be able to travel back into time. got my point? if you leave earth today at 1 million km/hr, then you will be back on earth before you started out(means you will have travelled back in time) it cannot be said in which year you will return because there is no relation for this case. but good luck with your time travel!!!
1144162
Actually, the current theory on time travel is that the furthest back into the past you can travel with a time machine is to the point that the time machine was created.\n\nAccording to this theory, to travel back into the past, you would need to create two worm holes.  One wormhole would exist at the time that you turn on the machine and the other worm hole would be put somewhere to 'age'.  At some time in the future, something could be put into the wormhole in the future and it would come out in the past.
363789
yes - i can travel forward in time already
1113547
I have done time travel. Evertime I come back to California from Japan. I leave around 16:00 in Japan and get home around 09:00 . Sounds like time travel to me.
189520
you can go back to the future
70282
No.  You'd need to have a wormhole.  Current theory predicts that transversable wormholes exist but would not allow time travel.  See reference for details.
114656
It's not necessarily impossible according to theory, but given our current technology, it's out of the question.  There's a lot of trouble with time travel theory, including multiple paradoxes.\n\nThe most famous paradox is, of course, the grandfather paradox.  It goes something like this: One day, after you've built your time machine, you decide to travel back into the past to shoot your grandfather before your father is born.  Here is the major paradox, if you suceed in killing your grandfather, you couldn't be born to go back and shoot him.  Just as well, the conditions required for you to shoot him couldn't exist and thus he lives.\n\nStill on the 'travel back in time to shoot grandpa' string, several other things could happen as well.  You could be transported to an alternate timeline, similar to ours, but not ours, and whatever you do there doesn't affect anything in our time line.  You could go back and try and kill your grandfather, but you are thwarted in every attempt, which tends to imply some sort of destiny or grand scheme.  You could try to go back in time but are ripped to shreds because every fragment of your being wants to be in its natural time.  There's a million and one other things that could happen.\n\nThat, I believe, is not necessarily answering your question, though.  Time itself is not understood by physicists even now.  What it is, no one is quite sure!  (However, I'm fairly certain time is related somehow to mass.)  One thing that's always for certain is time moves forward in a very linear fashion, cause followed by effect otherwise called casaulity.  I can't say one way or another why exactly we can't go back in time and I won't say it's not possible, some theories say it is.\n\nHowever, I believe Stephen Hawking offered up the best proof against time travel to date: Wouldn't there be time tourists from the future visiting us if time travel was feasible?
1186042
That's the problem. You can't go beyond the speed of light. It is the cosmic speed limit. But if you could, then you'll be able to travel through time, past and future.