The logic of the loop works fine but, you state the scientist finds the ship and repairs it and is not the builder of ship in the future.

The time ship has to be first lost by someone else.

If the scientist built the ship to begin with then the loop closes.



Hmm..here's a crazy loop...The grandson of the scientist finds the journal of his grandfather, it tells how he found and fixed a time machine and then lost it.

The grandson uses his grandfather's research to build an advanced time ship, something happens causing the grandson's time ship to take off and it lands in the past where the scientist finds it in the field and repairs it.

Back in the far future grandson turns on a recall signal, being smart enough to install one unlike his grandfather.

The fixed ship in the past receives the signal then takes off returning to the future. The sad scientist writes about it in his journal.

Unfortuantely the signal for recall had to travel back in time to work, it causes the time ship the grandson just finished to launch by mistake in the first place.

Finally the old patched up time ship lands back in the lab in the future where it began.

"What the hell happened to my ship!?"






-Oww! My head hurts_

There's another good link on wikipedia:

http://en.wikipedia.org/wiki/Time_travel

However I don't think time travel is possible at all. The wiki article mentions wavefunction collapse in relation to fixed pasts and open presents, but unless I missed something, it doesn't address one fundamental question I have regarding Vonn Neumann's Chain: The time machine is made of matter. That matter exists as matter because of its "history" of observation. This observation is dependent upon the prior interactions of the entire universe, as well as its faster than light interdepency upon the rest of the universe via quantum entanglement.

So it wouldn't really be time travel except as fantastically interpreted by the human mind. When in fact, what time travel would really be is a duplication of particles. Regardless of whether "you" exist or not in the past, the atoms that make you and make the time machine do in fact already exist as their constituent parts. The carbon that will eventually make much of your body - the materials that will eventually make the time machine.

The universe doesn't care what time it is, or any emotional ties the past creates on our psyche; the universe only cares that somehow, materials that already exist and interact with the entirety of existence at FTL speeds via quantum entanglement, somehow created exact copies of themselves out of thin air.

Time travel isn't really time travel so much as it is a copy machine.

If you could create exact copies of the materials that make you, that are untethered from the history of observation that caused the particles to exist in the first place, then you could time travel.

Maybe the reason we don't see time travelers is because they're too busy having fun creating objects out of thin air to meet their every need duplicating atoms that already exist, rather than messing with the space/time continuum.

peace
d=^)
-mando

Quote:Original post by HappyMiel
But if time travel is possible, does it matter whether the timemachine was made 'later'.
And theoretically in quantum mechanics a time machine COULD pop into existence spontaneuosly.

...not really. Quantum mechanics allows for the spontanious creation of particles from nothing, but it doesn't allow for a duplication of particles to appear in a different area of space.

Quantum teleportation, via quantum entanglement, (a form of time travel that "does" exist, i.e. the EPR experiment proven by John Bell) does create an exact duplicate, but once the duplicate is created the original is destroyed.

So traveling back in time would anihilate the old version of you, or what will eventually make you, once you pop into the past.

peace
d=^)
-mando

Well, I've had my coffe, so now it's time for my crap post of the day:

Imagine this...

I have a time machine programmed to cut a piece of stone from an ancient mountain, send it to (say) 10 years ago and then send itself (the machine) some seconds in the past and repeat the process of sending the same piece of stone exactly 10 years ago + some seconds.

mhh...? What would happend then? MHHH??!

You know, that's how martians made the pyramids...

Quote:Original post by TechnoGoth
That actually could be a interesting idea for a game, effect before cause. The earth is on the brink of destruction but a time rift allows the player to travel into the distant future. As the player travels era by era back to their own time the world gets progressivly worse as a result of the players actions in the future.

The player uses their time powers to change the fate of woman dying of a terminal disease, which causes a war to start in the past. Since the only way for a cure to be devloped in time to save the womans life is if a war occurs in the past.

I guess I just don't think of time in that manner. To me, starting a war in the past would/could save the woman in the future, but saving the woman in the future would not cause a war in the past.

This is kinda how I break this down:
If the woman needs a vaccine that's created during the war, you can't have the vaccine (and thus save her life) without the war happening. On the other hand, if you go to the future and find another way to save the woman's life, the war would've been unnecessary and wouldn't have happened.

As far as the subject of time goes, one game I really liked playing (while I actually played it) was Dark Cloud 2. For one, a character with a wrench and a gun for weapons is just cool. Also, as the characters, you planted things in the past and could jump into the future to see what they become. For instance (and if I recally correctly), you plant several trees together which end up growing into the tree god or something like that. You could also plant things in the past that you need, then go into the future and get them immediately.