Thus far, we are under the conclusion that it isn't possible, however, for all any of us know, it is possible, and we are being visited by people from the future right now. Be that pure speculation or otherwise, it can't be ruled out. I know we've had many discussions on time travel in the past, and it usually follows down the same path. Typically, we'd end up with a paradox conclusion or something quite similar. As was my past belief, if said person were to travel back in time to a point where they weren't suppose to be, they wouldn't ever arrive back in the past, for if they did, they would have changed the past, thus removing their birth from the future, and as such, wouldn't have been born to go back in the first place. That has always been my look on it, but for the moment, let us keep an open mind, and try a new approach. Lets say that time travel is possible, but everything in time is fixed, as in, nothing can actually be changed. If you could go back, you would pick a time and destination, and you would arrive, to see an old new world. What would you do? Change something perhaps? What if you couldn't? Say, for arguments sake, that you decided you were going to kill someone, be them of great importance, or not. For all we know, in a fixed-time theory, time wouldn't allow that change, for it is always suppose to happen, and as such, on your way to kill said person, you would actually end up dead yourself (maybe you get hit by a bus whilst walking across the street, or slip on something and break your neck, or maybe you'd simply suffer from a heart attack). If we go with this thought, then time travel could be possible, just, nothing could ever change, because time is set in stone (so goes the saying) and nobody would actually be able to change anything, regardless of how much they may want too. We'd essentially be able to travel through time as an observer, although even then, we could still die. The only part of this theory that doesn't work, is going to the future. As it hasn't 'actually' happened yet, would we be able to go there, and if we could, what would it matter what we did, as nothing has yet been set in stone... Gets a little complicated when you think of the future, but the past, I think works quite well, if this would ever be the case... Thoughts...?
My idea of time travel is you would be able to go back in time and kill your grandfather for say, and still be alive, you'd just be living in an alternate reality.
A paradox is almost impossible. After effects from the action will affect the person about to do said action such that all they cause is preventing themselves from doing what they set out to do.
Grand Master Overwatch Player
14th August 2008
Should you be able to time travel, there's several things. Let's say you want to go back into the past and change some event, or whatsoever. The changes you make in the past will affect the second universe (also 'second reality'), leaving the first universe (which is actually what had happened (in the first), or what is going to happen (in the second) unaltered. Changing the result of the now would require the two universes to be changed as well, assuming we could time travel, after all.
Formerly known as Graeme and Arld.
My theory of time travel is related to the newly named 4th dimension.
The universe is in constant motion. As such, traveling through time would likely also displace oneself in space.
You've heard of a hypercube, or tesseract. Well if space is folded in time, then you could travel between points in space. The effect is similar to a wormhole, but it travels through time.
Traveling to a different world would produce interesting results. As traveling faster than light changes the speed at which time flows, so you would likely drop out of FTL after you left.
...newly named 4th dimension...
This has been a known conceptual notion since the late 19th century and mathematically proven as such in the 1880's; also known as a tesseract.
Assuming we ever find a way to collect and harness the power of a star a stable tesseract could be formed outside of computer simulations in the real world. If we could do this, the possibilities would be endless; essentially we would be the masters of time and space. NASA's Jet Propulsion division is currently working on theorems for that fateful day. A stable tesseract and/or hypercube would allow us to warp (fold) space to travel the stars or perhaps as suggested travel through time.