Is time travel possible?

[WaylonJennings]

We're a few days now removed from the season finale on "LOST," I'm thinking - Is time travel possible? Even theoretically?

I know it makes my head hurt to even think about, but I remember reading when I was little books about the paranormal where people allegedly stepped back into the past briefly, etc., etc.

What does everyone think? Any amateur physicists/science fiction geeks on here with some ideas?

 

[Ace]

I already answered this question 200 years from now.

 

[hockeybeat]

Not anymore, what, with the clock tower from Back To The Future having been burned to the ground.

 

[PeteyPirate]

I'm about to make this a d_b.

 

[Chi City 81]

Yes.

 

[beefncheddar]

[marvin barnes] Hell yeah! They tried to put me on one. [/marvin barnes]

 

[Big Buckin' agate_monkey]

Jesus ... this is easy.
Here's the diagram:

 

[PeteyPirate]

Time travel is awesome! **air guitar**

 

[Herbert Anchovy]

http://www.pbs.org/wgbh/nova/time/sagan.html

 

[93Devil]

Time travel? maybe

Is it a lot easier to get from one end of the universe to the other than what we think right now? I would almost guarantee it.

In 10,000 years we will look like a caveman with a wheel to our descendants.

 

[User 1019]

Quantum foam. It's on roam.

 

[93Devil]

There have been some toy experiments in which, at just the moment that the time machine is actuated, the universe conspires to blow it up, which has led Hawking and others to conclude that nature will contrive it so that time travel never in fact occurs. But no one actually knows that this is the case, and it cannot be known until we have a full theory of quantum gravity, which we do not seem to be on the verge of yet.

- Sagan

Wow, that sounds a little bit like Lost.

 

[slappy4428]

Not anymore, what, with the clock tower from Back To The Future having been burned to the ground.

We have a winner

 

[JayFarrar]

I think you could go to the past, but I don't think you could go to the future.
Based on my extremely limited knowledge of quantum theory, since the future hasn't happened yet, you don't have a place to go to.
But you could go to the past, the thing that gives you a headache, especially if you watch sci-fi, is the paradox of time travel.
Say you went to the past and killed your grandfather, since you had never been born, how could you have went to the past in the first place?
Quantum theory gets into that a little, with each decision you make splintering off into a parallel universe with you doing the opposite of what you did. So in that fashion Universe A JayFarrar could go back and kill Universe A Grandpa Sotorios, but upon U-A JayFarrar's return, it wouldn't be to U-A, it would be to U-B, and he might not return as himself but as someone else and probably right at the point of his departure since in U-B what happened after he left would be in his future and since you can't travel to the future, no time would have passed.
That assumes you could travel back and forth with a physical body and that probably isn't the case, since the energy required would be on a scale would likely be impossible to generate, but, on the other hand, I think scientists have already discovered time travel happening at a microscopic scale with quarks and other energy particles.
If you don't have a headache yet, you aren't really trying.

 

[Ace]

Time travel used to be possible but not so much anymore with the high gas prices. Now you have to go back to the 80s to get a decent deal on gas, and that's just too much work.

 

[PeteyPirate]

I think you could go to the past, but I don't think you could go to the future.
Based on my extremely limited knowledge of quantum theory, since the future hasn't happened yet, you don't have a place to go to.
But you could go to the past, the thing that gives you a headache, especially if you watch sci-fi, is the paradox of time travel.
Say you went to the past and killed your grandfather, since you had never been born, how could you have went to the past in the first place?
Quantum theory gets into that a little, with each decision you make splintering off into a parallel universe with you doing the opposite of what you did. So in that fashion Universe A JayFarrar could go back and kill Universe A Grandpa Sotorios, but upon U-A JayFarrar's return, it wouldn't be to U-A, it would be to U-B, and he might not return as himself but as someone else and probably right at the point of his departure since in U-B what happened after he left would be in his future and since you can't travel to the future, no time would have passed.
That assumes you could travel back and forth with a physical body and that probably isn't the case, since the energy required would be on a scale would likely be impossible to generate, but, on the other hand, I think scientists have already discovered time travel happening at a microscopic scale with quarks and other energy particles.
If you don't have a headache yet, you aren't really trying.

Not here to talk about the past.

 

[HejiraHenry]

Einstein seemed to suggest so, and I'm not inclined to argue with him.

Michael Crichton had some fun with the question in the novel Timeline.

 

[Captain_Kirk]

Sure it's possible.

You don't go in no DeLorean, though. It's more like this:

(From the rather entertaining (and underrated) movie, Time after Time, with Malcolm McDowell portraying H. G. Wells).

 

[Herbert Anchovy]

http://en.wikipedia.org/wiki/John_Titor

This guy's lawyer is on George Noory regularly.

 

[Starman]

Sure it's possible.

You don't go in no DeLorean, though. It's more like this:

(From the rather entertaining (and underrated) movie, Time after Time, with Malcolm McDowell portraying H. G. Wells).

Yeah, but absolutely embarassing and amateurish special effects (even for 1978), mainly consisting of reverse-negative images, kaleidoscope projections on the screen, and the like.

Definitely a movie which could stand a remake, although "Kate and Leopold" from 1997-98 or whenever it was, was pretty close to one.

Back to the main topic, time dilation, one of the byproducts of Einstein's Theory of Relativity, in fact is time travel in a forward direction. NASA confirmed, when some of the Apollo missions returned from the moon, that the astronauts and spacecraft had aged a brief fraction of a second less than people left on Earth.