is it possible to travel back in time?  and alter the future.?
85408
Yes, if you have a time machine. Unfortunality mine is in the shop right now.
1110328
Possible now!\nwe go forward in time 1 day every day.
185677
1) You can't change a past event, that's nescessary for you to be able to change that past event. (You can't kill your distant ancestor)\n2) You can't go experience a future event, that requires someone from that future event to change your present event. (In the 'Planet of the Apes' movie series, Caesar went back to his past, and started an ape rebelion that built the world that Charleton Heston visited when he went into his future)\n\nBut how would you know? Changing the past or the future might create a tangent universe, that we can't experience.
559773
Firstly, don't overly concern yourself with the concept of fixing the past.  As a numerologist, Norman Shine, stated in one of his books: "Worrying about the future is just as escapist at living in the past."  In other words, if you spend all of your time worrying about the past, then you are wasting the present time and will have a very bleak future.\n\nIn regards to theories of changing the past, that's a theoretical astrophysics debate as well as a good philisophical debate question.  Either:\n\n1.) You can change the past and affect the direct future.\n2.) You can change the past, but the now new future is the future of another/parallel universe.\n3.) Somehow the laws of nature will prevent us from preventing the past/future (depending on your origin of time).\n4.) You change the past and cause a paradox and at that very moment the universe ceases to exist (according to Dr. E. Brown on Back To The Future)\n\nMy advice is to try and correct what is going on in the present to help your future.  You cannot change the past (that I know of), but you can change the future.  It may not be easy, but it is more possible than a quick-fix time machine-changing past patchwork.
281323
We live in a four-dimension universe, the fourth dimension being space-time. Time travel is THEORETICALLY possible. Just be careful if you go too far back in time and accidentally kill your father. Think about it!\n\nGod is spelled B-I-G B-A-N-G\nPBrax@netscape.com
1003820
Depends. You want to go forward or back. \nI *cough* actually have an entire theory about time travel. \nAnd that is, that there can only be one of you in existence at a time. Thus- if you go forward your putting yourself in your future self's body. And if you go back your putting yourself in your younger self body.\nBut- if I'm wrong and quantum physics 'same thing in countless positions at the same time' is right. Then you can be in two places at once. Therefore time travel- where you keep the machine and keep yourself how it is now, is possible. Then... I have no idea how you would go about it.\n\nIf anyone tells you to plug in the toaster and stick a fork in where the toast is supposed to come out though. Don't do it. Them electrical burns hurt.
813626
Sadly, I've actually heard about this before.  I can't believe how much useless junk I put into my head...I'd say pure fiction.  Its just more likely that he was some bored computer geek trying to get some attention.  Its still unclear whether or not time travel into the past is possible.  Based on current science I'm leaning toward the impossible side.  Oh well, 2036 will be here soon enough.  Then we'll know for sure.   ;)
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?
676857
Assuming time travel is possible, I think such a senario might be possible.  The trouble people have with time paradox lies in the assumption that every thing in the universe shares the same time line.  Why should that be true?  Here's an example:\n\n\n------  X  -------------------  Y  ---------\n\nAbove is our theoretical timeline.  Y represents me, in the "present".  I use my time machine to go back to X, before my grandfather sires my father, and kill him.  Logic dictates that I shouldn't exist.  What I'm suggesting looks like this, instead:\n\n---------------------------  Y  ------------\n                             \n\n---------------------------  X  ------------\n\nX & Y still represent me & my grandfather, but each of us now possess our own separate time line.  Instead of "going back in time", I simply hop off my timeline & onto his.  I am now free to perform my assassination, without consequence to me (beyond the obvious legal ones), as I was not born on this timeline, but my own.  Whether or not I can now return to my own timeline is an entirely different question, however.
693175
The ability to time travel. I could go back and fix anything before it happens.
194793
No way possible. Unless you can go back in time, then you would win every time.
848166
I think there is a difference between *seeing* past events--like looking at the 8-minute-old light from the sun--and time travel.  Time travel, as it is portrayed in novels and movies, involves the ability to actually be in the past or future, and I cannot see how that is possible.\n\nTo begin with, imagine going back to your own childhood.  You enter the house where you grew up and have a conversation with the kid you used to be. There you are, in your old kitchen, having a conversation with . . . yourself.  Do you see the probem?  There are TWO of you, the young child that you were and the adult that you are now, both together.  If you cannot accept the possibility of another person, or a billion other people, all of whom are you--just as much you as the person reading this answer--then time travel can't exist.\n\nNow consider a further possibility.  You travel back in time to the kitchen where your great grandfather was a boy.  Maybe that was 100 or 120 years ago.  But this time, instead of having a conversation with the boy version of your great grandfather, you kill him.   He never becomes a father to your grandfather, so your grandfather is never born.  Obviously, neither is your father ever born, nor, of course, you.  But if you were never born, who is it who just killed your great grandfather?  And, while we are at it, how can you be here?\n\nBottom line:  Just as a recording of an old TV news show can tell us what happened last year, light traveling through space may provide us with a record of what went on 8 minutes or 8,000 years ago.  But it is not time travel, which is impossible.\n\nGood luck!!
909079
Yes, it's possible but you would never be able to return from the future and you would have to travel close to the speed of light somehow.  According to Einstein's theories of relativity, if you travel close to the speed of light, time will slow down, so that hundreds of years could pass here on Earth while you travel at a fast speed.  So you would return to Earth in the year 3000 for instance at the same age as you are now, but you would never be able to travel back in time.  Time travel backwards is supposed to be impossible.
451645
I love your question, and I could elaborate forever, but I'll be brief.\nPast, without a doubt. That's what has brought me to where I am today. I would like to review the reasons, the rights and wrongs. Relive the beautiful moments as well as the dark ones, with the perspective of time. Even if I can change nothing, I would love to understand.\nAs for the future, the beauty of it are the thousands of unknown possibilities. I don't want to know what's coming: let it surprise me.\nAnd that's it. Now I'll daydream for a few hours, and wallow in nostalgia.
922481
Yes, it is very possible. If I had told people about my time travel experience, they would call me a retard. In year 2003 or 2004, I don't remember which year it was, I had kind of like the time travel experience reliving the same day. The same exact things happened to me in two straight days. It was the most weired experience I have ever had in my life. Yeah, reliving the same day.
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.
164691
According to Einstein, it's only possible to travel time to the future, although he never said that going back in time is impossible.\nTime slows down for you and your vechicle as you travel close to the speed of light (186,000 miles per second).  Anything outside is at normal time and speed obviously.\n\nTheoretically, if you travel 30 mins out into space at the speed of light and travel back to earth, you're only an hour old (by the way, at that speed, you've traveled an equivalent of six of our solor systems).  However, as you return to earth get ready to meet your great great grandson.\n***\nI don't know why.\nIf I did I'd own this freaking corporation.  *L*