Time Travel questions


Temporal Novice
I have been mulling this over somewhat, and I cannot get my head around it at all.

I can understand - with a small amount of thought, how a 'one shot' forward journey could be accomplished - 'simply' accelerate towards the speed of light, and cover a decent distance at a decent fraction of light, and time appears to pass very quickly around you, on your return you have 'missed' an amount of local time, and you have therefore travelled forwards in time.

Simple really - all you are doing is effectively experiencing time at a different rate, due to the time dilation effects of close-to-light speed.

However, backwards travel I assuming a singular universe, or even assuming a multiple universe theory, I cannot understand at all.

Assume for a moment if you will that I have a device that allows backwards time travel.

If the past is fixed, as time has already passed, then I can only see two possibilities.

1) I can only observe, and cannot influence anything in my version of the past.

2) Any influences I manage to make are already a part of history.

The second statement is the one that I have serious trouble with, because having made those changes, I have changed my history, or rather part of my history exists before I had made my trip to the past.

Say I travelled backwards, and injured somehow a younger version of myself, until such time as I had done it, in my own (later) timeline, would I have the scar, or not ?

If I already had the scar prior to making my trip backwards, and I was fully aware of how it happened, then surely it has somehow become my destiny to travel backwards and injure myself.

Now if someone can explain to me how this works /ttiforum/images/graemlins/smile.gif

If you consider the multiverse theory, then each version of myself in the various pasts are healthy, and there is no way I could ever do anything like that, but again I am not sure I understand the action of a multi-verse, anyone care to explain ?

Re: I know the Answers

BTF 123 only provoke more questions than they actually answer.

Any more takers ?

if the past is mutable, by us in our present, or by others in the future, does that mean that we are but passengers on a journey through time over which we have no influence over ?
Re: I wonder

Hmm also i have this 1 question, im sure all of you wondered of what im about to ask...
If you go back in time, and have sex with yourself, would that be considered masterbating, or gay. /ttiforum/images/graemlins/confused.gif
Re: I wonder

Lol, if a say 25 year old me from the future came up to me and tried to have sex with me, I'd shoot his head off.