Time Travel-Is it Possible ?

[Maccabee]

Is it possible to travel through time ? What is your opinion about John Titor's claims?

[Spurius]

No (not on a macroscopic level, anyway) and a hoax.

[David Deas]

Is it possible to travel through time ? What is your opinion about John Titor's claims?

You travel through time every single day. Rephrase your question.

[Psamtik]

You travel through time every single day. Rephrase your question.

Who said time exists at all?

[Medicus]

Is it possible to travel through time ?

Yes and maybe.

The closer you get to the speed of light, the slower time goes for you. So effectively you travel into the future. You might spend a year travelling in space and return to Earth to find ten years has passed there. I'm sure other, more scientific-minded members could explain better.

As for traveling through time as seen in movies like BTTF, I'm not sure. Maybe.

What is your opinion about John Titor's claims?

Bollocks. It scared me the first time I read it, but look closely. It's crap.

[Axeman]

God I hope not, I just feel that is one line we shouldn't cross, there is a part where the persuit of knowledge should end, no matter how noble an endeavour it may be, there are just too many things that could go wrong.

[Chaigidel]

I dont think its very possible at all-- but I dont know everything

there really arent any ways that I can think of that time travel would be possible in any manifest way-- as another said particles do exibit strange time dilations but this could be attributable to them going near the speed of light after reaction.

[Zodiac]

What if the Big Bang occured because someone went back in time. I say Let's give Time-travel a try and see how much we screw up the future.

[Bokks]

What if the Big Bang occured because someone went back in time. I say Let's give Time-travel a try and see how much we screw up the future.

Hmmm, if you think about it, though, you'd never be able to change the future, as the future would have been built upon by what was already done. I think that should time travel ever be done, it is quite possible that the Big Bang could be a construct of some "Krononaut".

Anyway, I've thought of a lot of different possibilities with time and the travel therein, and one that occured to me is the fact that travelling through time requires a person to add a greater amount of matter--atoms--into a place that wouldn't have them otherwise. Think about it, rule numbero uno about matter preservation: matter can neither be created nor destroyed. Would a person travel through time, it may be possible that he'd destabilise the whole space-time continuim should he not have also transsported an equal amount of matter to his own time.

Now, judging from the fact we still exist, and that if it would happen it already has, this has not occured. But still, that elementary physics fact that has been overlooked by every movie and book is pretty interesting...:hmmm:

[Simetrical]

Anyway, I've thought of a lot of different possibilities with time and the travel therein, and one that occured to me is the fact that travelling through time requires a person to add a greater amount of matter--atoms--into a place that wouldn't have them otherwise. Think about it, rule numbero uno about matter preservation: matter can neither be created nor destroyed. Would a person travel through time, it may be possible that he'd destabilise the whole space-time continuim should he not have also transsported an equal amount of matter to his own time.

Indeed, if you transported the same object back in time repeatedly at a sufficiently rapid rate, you could create as much matter as you liked. (It would disappear eventually, of course.) But really, this isn't such a huge worry. You could always wave away conservation of mass by generalizing it slightly, one way or another. I can't immediately think of anything both elegant and not too general, but then, I'm not a theoretical physicist, am I?

The possible effects of causal loops are more problematic, barring many-worlds sort of stuff or Terry Pratchett's little group of monks that pieces time back together when it breaks apart due to paradoxes. If I launch a particle through a wormhole at a trajectory such that it would emerge at an earlier point in time and deflect its passage into the wormhole to start with, what happens?

It should be possible to handle that with some new fundamental law, of course. The simplest candidate is "time travel is impossible".

[LSJ]

Time travel any way other than forward is impossible, at least for us to perceive. Because if we went back in time that involves the atoms and tiny subatomic particles going back to where they were x minutes ago. So if you went back in time your brain would be as it was before you did it... if it was possible to travel backwards you would never know you did it, and you'd be stuck in an unending time warp of you saying "lets press this button" and then pressing it, going back to before you pressed the button, and then saying again, "lets press his button", and over and over until God smashes you for defying time.

[David Deas]

Anyway, I've thought of a lot of different possibilities with time and the travel therein, and one that occured to me is the fact that travelling through time requires a person to add a greater amount of matter--atoms--into a place that wouldn't have them otherwise. Think about it, rule numbero uno about matter preservation: matter can neither be created nor destroyed. Would a person travel through time, it may be possible that he'd destabilise the whole space-time continuim should he not have also transsported an equal amount of matter to his own time.

By that logic no object could move through time at all.

I think the most simple observation we can make that answers these questions is the fact that we have not been visited by a single time traveler. That means time travel with the kind of infinite freedom we all dream of is not possible.

In General Relativity you do have closed time-like curves, but these are not very meaningful. A person traveling along a closed time-like curve would not know it. Neither would they have very much of an existence.

[Bokks]

By that logic no object could move through time at all.

I know you already responded to another comment, a few days ago, but I've been a bit bogged down over the week.
Anyway, my assertion that there needs to be the same amount of matter from one moment to another doesn't stop an object from going through time, it simply states that you need the same amount of matter from one time to another time. Matter does move, all the time, but we have the same amount of matter now that we had 15 billion years ago, and the same that we will have 29 trillion years from now. Should someone transfer themselves from one time to another they would be changing the overall mass amount, even thought the change would be the slightest, since obviously one person doesn't amount to much in the whole of the universe.

That's what I meant... your assertions were incredibly astounding, but I don't think they really interrelate. Things age, they travel through time, they move around everyday. However, the amount of matter that makes up such things is the same from one moment to the next.
They are if you really put stock in the theory of a closed universe, anyway, which I actually don't, since there are obviously black holes and many aspects of our iniverse that we don't understand. But even with those in effect, the whole system still does not lose or gain any matter, the whole "polyversal" system, if you will.


Now, there is always the threat of a "paradox" should you succeed in traveling back in time, but really I don't think they are really possible. First off, should you go back in time and meet a former self, the you that went back in time would have the memory of such an encounter from the past. Beyond that, there are 6 billion people in the world, it is very easy to get lost. Also why we may have not met people claiming to be from the future. Well, that and it may not be possib;e. Or the people that have have been sent off to the nut-house, after all saying you're from te future isn't the most "clinically sane" thing to do.
Personally I put teleportation and time travel in the same basket, should it be possible to teleport it would likewise be easy to time travel. Since neither have been accomplished, it is really speculation to talk about both.
But hey, speculation is healthy for our advancing minds!

[Spurius]

I dont think its very possible at all-- but I dont know everything

there really arent any ways that I can think of that time travel would be possible in any manifest way-- as another said particles do exibit strange time dilations but this could be attributable to them going near the speed of light after reaction.

Actually the time dilation observed with cosmic ray muons is itself a bit of a circular argument, to explain their longer-than-hypothesized lives. They live too long, THEREFORE there must be time dilation. Before they were observed, noone predicted they would exhibit it. It's a bit of a stopgap, from one viewpoint. Theory about muons could be wrong, too.

But, even accepting Einstein and wormholes and Kerr black holes etc, the energies required to do something with even a tiny bit of mass, are absolute showstoppers.

Timetravel as an idea, I think, is based on the fact that just about all calculations in physics are reversible. Theory goes two ways, almost always - but not always (as with KL-mesons) :

http://www.answers.com/topic/time-re...cat=technology

Which probably means it NEVER does, even if we may think so. Time's a one-way street, by the looks of it.

Mind you, I would LOVE a DeLorean with a flux-capacitor, too.

[Medicus]

Models of fictional time travel physics - a look at the way time travel is modelled in movies, TV shows, and books.

Also, the Golden Rules of Time Travel.

[Oswald von Wolkenstein]

Bob Twator has refuted most of Jack Titor's claims.

[Eric]

Not travelling BACK in time, no you can't do that. However, through the miracles of relativistic space travel, you can travel FORWARD in time while staying the same age. I.E: You're 22 when you leave Earth in 2010 travelling at relativistic speed. You come back to Earth in 2100, and you're still 22. Isn't relativity a marvelous thing?

[Spurius]

Alas, relativistic does not equal c exactly - you will still age.

[Medicus]

Alas, relativistic does not equal c exactly - you will still age.

Unless you're put into cold sleep. But that's not perfect either - best you could hope is only aging a few months or a year (even if you're unconscious for most of that period).

[Spurius]

best you could hope is only aging a few months or a year (even if you're unconscious for most of that period).

Even at near 0 Kelvin, matter still vibrates several trillion times per second. Cryogenics in its current form is definitely not perfect stasis, and maybe it will never be reached by simple cooling.

If your destination is say, the Andromeda Nebula, you'd probably step out a mummy, anyway.

Time's a harsh mistress, won't be denied that easily.