The question I would have is that if you go back in time, will the universe still exist there or do you fall off the edge of the space time manifold?
I have come from the future in a time machine to make sure it never gets invented.
No. Because if they ever did, someone would go back in time and do something to delay its invention so that eventually it will never be built.
Just go to Afghanistan, you'll be transported to 1365.
I've had this long-standing thought that time is just a 'fuel' of sorts. I mean, we use it at varying rates - when we are really concentrating or involved on something, we use it really quickly. When we have nothing to do or think about, we use it really slowly. As we get older, we tend to seem to use it more quickly. Maybe in some other dimension, time is more like space, where it is something which has substance that we can move through. In this dimension, though, I tend to think that time has no substance. While I'm fascinated by time travel, I truly do not believe that it is physically possible - not in this dimension anyway.
At least the direction to which our scientific beliefs are heading, time and space are not different things, but difference facets of the same thing. Recently I have been following the works of Fay Dowker on this subject, that space-time is not simply a set of measurements but is a tangible item unto itself.
definitely very interesting. I certainly don't think that time & space or spacetime are just measurements, I just highly doubt that we are large enough to effect them on a grand scale (like an ant crawling on a piece of paper can't fold the paper - it doesn't mean that the paper can't be folded by someone/something that is large enough and above/around the paper).
Still looking for a Delorean to convert. Thought about useing a VW Micro Bus, but thought it might freak Hitler out, when I returned to assassinate the little dweeb, with my personal Particle Beam.
I will kidnap bin ladens mom before he is born and move them to Huntington Beach CA. Osama will become a Surfer Dude and the only things he will want to kill is a six pack of Bud and some gnarly waves.
I do not know if it could be done and i guess the risk of my action may kill off the world <br />
but i would go back in time for just a few minutes to make sure my wife knew i loved her <br />
as when i told her that was just as the aircraft i was in was hit by a SAM and i willnever knowif the words got thought<br />
it was 6 months before i came out of the coma and stayed out and was told my wife was killed the next day and out mother took her won life thinking bothher kids were dead [ she really was not my mothers she just gave me home free of abuse at 12 years old and she did this knowing her daughter loved me as much as i loved her]
One physicist has already made a serious attempt to create a time machine using counter rotating concentric laser beams passing through a Bose-Einstein condensate. The idea was to increase their relativistic mass by slowing their momentum to a crawl and, thereby, distort space-time enough over a tiny space to create a wormhole just big enough for particles to pass through from the past. So far no success and there are plenty of theoretical reasons why it could be impossible. <br />
If it is possible current theories suggest temporal loops would occur and a sort of Heisenberg Indeterminacy would apply. The more you learn about the future the less you can change it and the past can never be changed. For example, you could travel back in time and save your own life because, obviously, you already did so and there is no avoiding what has already been done. However, you could not go back in time and kill yourself at an earlier time for the same reason.
Does "physics" include math and imagination for you? In a sense, anything is possible.
Figure out how too achieve tachyon control.. and then yes. But good luck getting back