Time Travel

My apologies if this post is not in the correct area. i’m not sure where it should have been posted considering the nature of the question, it’s a technicality.

anyone…concerning time travel. if time is described as a dimension along which one could describe an objects location at (x,y,z, t) ‘t’ being time. then lets suppose i’ve built a time machine to move only along the axis of time…i step into it, punch in 5 minutes ago and voila! where do i find myself? am i stepping out of the machine only to find a startled look on “my” face to see me stepping out of the machine, or do i find myself turning immeadiatly frozen because i only moved along the axis of time and not space. the galaxy is rotating, the solar system is rotating, the planet is rotating in orbit, 5 seconds ago…it would have been about 10,000miles away from ‘now’. i hope i’ve somewhat described what i wanted to. heheundefined

It’s all fantasy anyway so you can make up any scenario you’d like. Time travel supposedly works on paper but mostly pulp.

H.G. Wells came up with the idea, and it’s a pretty cool idea, so some folks work backwards(no pun intended) to make it all work out.

Since the Earth moves at breakneck speed through the galaxy, if you set your machine to deposit you at the EXACT SPOT you were at five minutes ago, you might be flailing around in the hard vacuum of space.

There are no privileged reference frames; your travel through time would also have to involve travelling through space (or staying put) in relation to some point of reference - if this point of reference is your laboratory workbench, then yes, you get to step out and surprise yourself before you set off (and maybe convince yourself not to go, in which case you wouldn’t have been able to stop yourself and therefore… oh, you get the idea). If your point of reference is the sun or the centre of mass of our solar system, or the centre of the Milky Way Galaxy, then here certainly won’t have been here five minutes ago and you’ll probably be in a tight spot.

Or, your consciousness returns to the earlier point in time, leaving your body in the “present”. (Note that this doesn’t involve the violation of the conservation of energy, as does the scenario in which you return with your body.) You then re-experience the last 5 minutes, then your consciousness returns, etc., in an infinite loop.

This scenario doesn’t seem to be used much in SF. The only instance I know is Charles Williams’s Many Dimensions, which is not quite the same thing anyway.

Kurt Vonnegut’s Timequake had a similar premise. Everyone on earth re-experienced the last ten years, without the ability to influence anything at all.

Just as we use money as an abstract measure of the value of material, we use time as an abstract measure of movement. Money evolved from trading two objects of roughly equal value directly, to expressing the value of both objects into an abstract value.

If you keep this in mind, you’ll see that time travel is changing the way your body moves relative to everything else in the universe.

Traveling into the past would require everything in existence to move backward the exact way it has moved forward for the period you wish to travel into the past. In other words, there are few things less likely or possible in the world than travelling back in time.

Travelling into the future requires you to stand still, and the rest of the world to move forward. This is more likely - for instance theoretically you could freeze your body and thaw it again later, at least in theory, and that would be travelling into the future for the period you were frozen. Scriptwriters seem to be picking this up.

To get back to your question, you would only move in so much as wherever you were stored was moved. Say that you were frozen in a box. If that box were left at the same place while time passed, your location wouldn’t move much and stay pretty much where it was when you ’ started your time travel '. But of course someone could also just pick you up, put you on a plane and take you to Australia, or send you off into space, or whatever.

Does any of this make sense?

It also explains why gravity seems to bend time - it doesn’t, it affects movement, and if the movement is measured in time or is used as a reference for measuring time (ever noticed how all clocks have to move to be able to tell time?), it may appear to affect time, but in fact it just affects the measurement of moving by influencing the movement.

Gregory Benford’s Timescape deals with sending messages via tachyons back in time. Once they figured out where the world was several years ago in relation to where it is now, the tachyon beam (which moves faster than light) was aimed at that spot.

Michael Crichton’s Timeline deals with compressing people like a 3-D jpg image and sending them through the quantum foam, wormholing in a sense to an alternate quantum reality. I like this idea, since you don’t actually travel back in YOUR time, but a very similar one… and hence you can’t murder your grandfather and return, you can only murder your grandfather from an different quantum reality.

damn. Forgot to add… that the tachyon beam sucessfully sent messages, but they then realized that they couldn’t really affect their present or their future, but instead created a separate time line, similar, I suppose, to a new quantum reality.

This is really the only explanation that has even a noding acquantance with the laws of physics. People seem to be forgetting that science fiction is in fact, fiction.

Philosophically, since you do not remember seeing yourself 5 minutes before traveling backwards in time, your experiment did not work since it would create a paradox (two conditions that cannot exist simultaneously). Fiction attempts get get around the paradox problem by creating “parallel timelines”. Essentially, a new reality is created from your perspective (think Marty McFly traveling Back to the Future). Another literary theory is that history is like a movie. You can’t change the past, you just become part of it (Think Terminator movies or 12 Monkeys - history unfolds exactly the way it is supposed to because someone who goes back in time fullfills whatever roll they are supposed to play). Problem with this theory is that it basically removes all self-determination. Everything happens the way it happens because it has to that way.

Well, when you move through x,y,z, you are still constrained by gravity in some manner, are you not? So would not the same apply theoretically if you moved through t? In other words, as you move back in theory, would not gravity keep you still firmly rooted to where you started from?