Time travel?

[mosimo]

Okay lets start a discussion here.

Time travel plausible or crazy?

Lets see how much life we can give this discussion.

[MrD]

We have more chance of coming across a time traveller as the barriers between countries come down and it is not so unusual now to come across people radically different from our own culture and community. How do you know you haven't already met one?

[mosimo]

If a person from the future came back in time to our present day one of three things could have or could happen. The future could have a high respect of the past and therefore would only travel back to study it and not to disturb it in any way and therefore no one would know that they were even from the future.

The time traveler could travel back in time and performing technical advances and that sort of stuff entirely change the future. In that case we would already know if it were possible because it would have made big news.

Thirdly the traveler could have traveled back in time and after declaring himself a time traveler people would think him crazy having him killed as demon possessed.

Nevertheless is time travel scientifically plausible?

[Literary_Cat]

Not possible. Time always goes at the same speed in one direction. This is not negotiable.

[mosimo]

There have been experiments done in which speed has caused an atomic clock to go slower. Therefore time can be slowed down. Those same experiments have brought up the hypothesis that the speed of time and the speed of light are the same. Therefore if matter could travel faster then the speed of light the matter would travel back in time hypothetically speaking. Therefore if matter could travel back in time could not it also go the other way?

[mosimo]

Refute me. Come on!

[bluevictim]

Originally Posted by mosimo

Nevertheless is time travel scientifically plausible?

Originally Posted by Literary_Cat

Not possible. Time always goes at the same speed in one direction. This is not negotiable.

There are a number of respected scientists interested in the possibility of time travel, so I wouldn't blithely rule it out. A number of paradoxes do come up. What if someone travels back in time and kills his parents? If time travel is possible, why hasn't someone from the future come back in time to tell us? Maybe some kind of time travel is possible, but not in the way we imagine it in movies. Maybe it's possible only to go into the future (faster than usual), or it's possible only to go to places in the past that are far enough away so as to avoid contradictions.

Originally Posted by mosimo

There have been experiments done in which speed has caused an atomic clock to go slower. Therefore time can be slowed down. Those same experiments have brought up the hypothesis that the speed of time and the speed of light are the same. Therefore if matter could travel faster then the speed of light the matter would travel back in time hypothetically speaking. Therefore if matter could travel back in time could not it also go the other way?

The experiments that you mention relate to pretty standard special relativity. Your account is close, but a little off. The idea is that the length of time intervals between events depends on the speed of the reference frame in which it is measured. So, if there are two observers with clocks, and observer A is going faster than observer B, observer B will see that it took longer than five minutes for the clock of observer A to go from noon to 12:05pm, whereas, of course, it took exactly five minutes for observer A. Thus, to observer B, the time "slowed down" for observer A. As you said, in the framework of special relativity, traveling back in time would require going faster than the speed of light.

However, if there is the right kind of "curvature" (aka gravity) in the universe, it might be possible to go back in time without going faster than the speed of light. The effects of "curvature" fall under the domain of general relativity, which is the framework used for studying things like black holes.

If you ever have kids and one of them when he's eight years old accidentally sets fire to the living room rug... go easy on him.

[falloutLXIV]

time travel? not possible, at least not now. maybe in another 30,000 years, but not now and definately not soon. that is all i have to say.

[travel-exchange]

time travel is craziest thing time always travel forward never backward,It is also good to move forward then looking backward that cant be changed

[soundofmusic]

Stephen Hawking now believes it possible. Einstein thought it possible. It seems that the difficulty is not time travel itself; but finding the energy power to move a body through time. Of course, we've all heard stories of the "Philadelphia Experiment"; and what of Astral projection...a bit of a segway, of course

[Lokasenna]

Originally Posted by soundofmusic

Stephen Hawking now believes it possible. Einstein thought it possible. It seems that the difficulty is not time travel itself; but finding the energy power to move a body through time. Of course, we've all heard stories of the "Philadelphia Experiment"; and what of Astral projection...a bit of a segway, of course

I seem to remember Hawking did qualify that comment by saying that the traveling object would have to be crushed into a particle small enough to pass through the holes in the quantum foam, the very material of reality itself. I doubt anyone would be in the mood for tourism after that!

[Paulclem]

Perhaps it's only possible through reincarnation.