Time Travel... Possible without changing the past ????

[brigade101]

I was thinking the other night that if time travel was possible that if you did go back in time you would in fact change something simply by being there. In that by physically standing there you are misdirecting/collecting germs, particles, pollen etc... from the course thay were meant to take. Maybe it wouldn't cause the world to give rise to Molemen but what if it lead to some organisim not getting to small mammel A who needed it to get resistance to germ B and that killed him which led to the death of C line of animals and humans if I explained that right.

[Nooblar]

Well, physicists have already proven that time travel is theoretically *possible*, so IF the universe went against the odds to evolve life, then we must assume that it also went against the smaller odds to send something back in time. Therefore, the universe we are experiencing today is actually the result of any effects of any and all time travel TO points in our history.

And if you believe in a supreme creator and not evolution...then it's even easier to explain why time travel doesn't ruin history.

I've thought it through a lot (yeah, I'm weird like that) and the conclusion is the same every time. Of course, that's all based on the assumption that time travel is even possible.

[kenjib]

Yeah, the Butterfly Effect (a principle in chaos theory) is what you're talking about:

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

The article even specifically mentions the time travel issue you are talking about.

[CornPuff]

Physicist have not proven time travel theoretically possible.

Theoretical physicists may have theorized about it, on which popular science or the like may have written a flashy article or something, but its far from proven.

Time travel to the future is sorta possible, but it depends on how you define time travel Time travel to the past? Thats the realm of mind screw science fiction... which I thoroughly enjoy.

Back to the Future Part I and 12 monkeys are both awesome.

[kenjib]

Also, if faster than light travel were to ever become possible (also not theoretically possible at the moment), you could see the past and it wouldn't create a paradox of causality.

[Bannister]

You can't go back in time and change the past in a way that you wouldn't exist and develop the ability to travel back in time because if you didn't exist to travel back in time then you would have never traveled back in time and changed the past in a way that you wouldn't exist and develop the ability to travel back in time.



Chew on that!!!

Bannister

[CornPuff]

From wikipedia:

Time travel to the past is theoretically allowed using the following methods[4]:

* Traveling faster than the speed of light
* The use of cosmic strings and black holes
* Wormholes and Warp drive

lets break it down:
* Matter cannot travel faster than the speed of light
* Cosmic Strings have never been observed, and are impossible under current theory (a cosmic string is a 'wrinkle' in space-time caused by quantum randomness during inflation
* we have no model of physics past the event horizon of a black hole, which is why they are so awesome. If you did manage to travel backwards in time, you could never get out, so i guess its moot.
* Wormholes, cool theory, never observed. Because you could travel back in time in one, i'd say they can't exist.
* Warp drive? not until we find dilithium crystals

maybe im wrong. maybe it is theoretically possible.... I'm pretty sure travel to the past breaks causality (the kill your own grandfather paradox) which means it doesn't have much of a place in current models.

hmm.....

[CornPuff]

Actually, in current models you can see the future while traveling at relativistic speeds, you just can't communicate or change it.

Want to see the past? look at the sun. That happened minutes ago. Want to see 15.4 billion years into the past? look at the cosmic microwave background radiation. You can't see any farther back than that unfortunatly.

For a more moderate glimpse into the history of the universe, watch a big supernova. Most of those happened billions of years ago but we are just now seeing them.

[brigade101]

Originally Posted by kenjib

Yeah, the Butterfly Effect (a principle in chaos theory) is what you're talking about:

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

The article even specifically mentions the time travel issue you are talking about.

Chaos ? And I always thought I was Lawful Neutral.

[brigade101]

Originally Posted by CornPuff

From wikipedia:

Time travel to the past is theoretically allowed using the following methods[4]:

* Traveling faster than the speed of light
* The use of cosmic strings and black holes
* Wormholes and Warp drive

lets break it down:
* Matter cannot travel faster than the speed of light
* Cosmic Strings have never been observed, and are impossible under current theory (a cosmic string is a 'wrinkle' in space-time caused by quantum randomness during inflation
* we have no model of physics past the event horizon of a black hole, which is why they are so awesome. If you did manage to travel backwards in time, you could never get out, so i guess its moot.
* Wormholes, cool theory, never observed. Because you could travel back in time in one, i'd say they can't exist.
* Warp drive? not until we find dilithium crystals

maybe im wrong. maybe it is theoretically possible.... I'm pretty sure travel to the past breaks causality (the kill your own grandfather paradox) which means it doesn't have much of a place in current models.

hmm.....

Matter cannot travel faster than the speed of light

Even if people made an engine capable of doing it ? Like the stress form it would be too much ?

[kenjib]

Originally Posted by brigade101

Matter cannot travel faster than the speed of light

Even if people made an engine capable of doing it ? Like the stress form it would be too much ?

It's because your reference for time changes as you increase your speed. The faster you go, the more time slows down for you. So from the perspective of someone travelling the speed of light, their speed would be infinite because time would be moving infinitely slow. So it's not just that you can't travel faster than light, you can't even travel at the speed of light (since from the perspective of the mover it's infinite speed). You can only approach it.

[D-Dyzzle]

if we could go back in time, we couldnt change the past, we allready would have before we had the power to.

hey brigade, you play dnd?