Do you think time travel is possible?

there must be an occaision where someone going back and deleting themselves from history is not a paradox but desirable
 
There are no paradoxes resulting from actions taken after traveling back in time. Quite simply, you are affecting a universe different from the one in which you were born (if it makes sense to say such things... you were born in a universe different from the one in which you now live, if you insist on being clear about things). Changes to other universes do not affect the universe you came from.

For example: you go back in time and kill your father. Obviously, that event didn't occur, or your father wouldn't have been around to impregnate your mother. Therefore, the universe in which you kill some man is not the one your father was from; the man you kill is not your father, but a many-worlds extension of your father. In fact, there is no "your father" except as a blurring across universes. Killing one of them has no effect on your future, because obviously that one has no causal relationship to you at all.
 
Consider the following:

The past is in the past... ie: it has already occurred.

100 years ago, I stepped out of some strange portal and wandered around for awhile. It has already happened... happened 100 years ago. 20 years from now, I will have invented a time machine and use it to travel back in time 120 years.

I can't change history, because I was a part of it. Whatever I do in the past has already occurred.
 
Originally posted by StuTheWise
Consider the following:

The past is in the past... ie: it has already occurred.

100 years ago, I stepped out of some strange portal and wandered around for awhile. It has already happened... happened 100 years ago. 20 years from now, I will have invented a time machine and use it to travel back in time 120 years.

I can't change history, because I was a part of it. Whatever I do in the past has already occurred.

It's not quite that easy. The idea of a paradox is a serious concern, but your solution is not the way out.

For instance, imagine that you have just created a time machine. You decide to play a game: if you (another you) walks out of the time machine within the next hour, then you destroy the time machine, and it is never used. On the other hand, if nothing happens inthe next hour, you step in the time machine, set the controls to go back an hour, and step out... and then witness yourself destroy the time machine.

Good pardox, no?

The solution isn't that history has already occured with any time travelers a part of it, as this example shows. The solution is that each scenario leads to a different branch of the multiworld universe. The "you" that steps out of the time machine (if he does) is not "you", but a "you" from a different universe... one in which no one stepped out of the machine, and the "you" there stepped in.

Time travel is not so much going back to earlier times of "this" universe, but rather going to different branches of the multiverse that are at earlier relative times.

It would not be at all illogical for you to go back in time, and find that your grandfather had already been killed. It's simply a different universe, and there's no reason to think you'll get extrodinarily close to the events in the universe you left.

:confuse3:
 
You're right, my little ditty is not a solution to the problem of a paradox. I just wanted to get the ol' noggin' crackin'.

I tend to believe that backward time travel is possible in the real sense... as in traveling back to a time previous in our own universe. Traveling to another universe in an earlier relative time is not really time travel, but travel between other dimensional universes (Sliders style?) Traveling to another universe brings up a possible situation that you brought up about your grandfather already having been killed. In that universe, you are never born (even without interference from yourself), but in your own universe things remain the same.

I haven't always believed backward time travel within our own universe was possible. But recent study has changed my mind. From what I have read and seen on the Nova documentary, the world's top physicists seem to think that backward time travel is possible and many seem to agree on similar theories about how that is possible. Not being a brainiac myself, I can't even pretend to fully understand the stuff these physicists are spouting, but for the most part it makes a lot of sense.

And like I mentioned before, a popular theory among these scientists regarding paradoxes is that there is some unknown law of physics that would prevent a paradox... just like in the known laws of physics, experiencing 50 G's (50 times Earth gravity) would cause you to splatter, going back in time and killing your grandfather before he has the chance to father your father would be prevented by the "anti-paradox" law. Again, they cited the incident with the billiard ball as an example of this.

I saw an old Twilight Zone episode in which a time traveler travelled back and attempted to assassinate Hitler before the start of WWII. As he brought his rifle scope to bear on Hitler's head, he pulled the trigger, but the bullet was a dud. He rechambered and pulled the trigger again... another dud. Rod Serling's vision of the "anti-paradox" law?
 
Hmm... I'll have to see if I can come up with any links.

So far, although there is no fundamental reason why time travel shouldn't be possible, the necessary distribution of matter and energy to create such an even is not, well, easy to achieve.

One involves creating a wormhole and moving one end at near light speed. (yeah, easy, right?) Another involves a pair of parellel cosmic string (which we're not sure even exists) and a spaceship looping around the pair at near light speed. Another involves a rotating cylinder that has infinite lenght (seen one of these lately?).

That's why I don't think we'll ever achieve travel on any large scale. However, if the principles are sound, I can imagine in a laboratory environment enough energy being focused at a point to allow an EM signal to be sent through.
 
Part of the article that appeared in Popular Mechanics can be found here.
A search for Kip Thorne at you favorite search engine will probably turn something up.

If you're interested, page two of the above link has a few words about faster-than-light travel as well as the theory that pulsars were actually built by aliens, and not naturally occurring phenomena.
 
Hi all,

Personally I don't think its possible, I was of the mind that you could but assessing articles I've read and personal opinion I find that most events in our universe are just pictures which go out and eventually come back which was spoken about decades ago and that its possible to see every moment as pictures come back. I haven't read anything that changes this whether speed or portals or dimensions.

For one thing even if you could see something that has happened doesn't mean you can interact with it, otherwise if aliens could do this life here would constantly be changing even deja vu feels like you've done this before but doesn't change anything as if pictures of what has happened mix with other universes or different planes of existence at times which I believe is possible but still doesn't effect change, might call it leakage but thats about it.

So whether we could jump time backwards or forwards still doesn't mean we could interact which is why I don't think time travel is possible. The human race is still evolving from a primeval time and that is a constant which doesn't change only intelligence or discovery causes change but not the act of time travel if it were possible. Jumping to another plane or dimension would only change that plane but not ours.
 
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