Time Travel : Is it possible? (GPS, Monster, satellite, sound)

[atreidi]

What do you think about time travel?

[jufrbo]

It is possible to travel to the future in theory. Supposedly if one revolves around the Earth fast enough for enough time more time will pass on Earth than it does for him. I was told by a physics teacher that if a man orbited the Earth at the speed of light for 40 years, 10,000 years will have passed on Earth. It all based on Einstein's theories. I don't whether or not any of them would actually work. But Einstein would argue that it would be impossible to travel backward in time. Whenever some one who is schooled in physics tries to explain that sort of thing to me, my brain shuts down.

[Marodi]

I figure it's probably possible. Though i'm not a physicist, time is a constant and I don't think that a change in velocity will change that. However there probably is a way to alter the fabric of time to move between periods of time, both forwards and backwards.

[rcsteiner]

Originally Posted by atreidi

What do you think about time travel?

I'm travelling forward in time right now!

[collected_eve]

Ever heard of the Hyper Dimensional Resonator (HDR)? I know, sounds corny, but I've actually been following it since I was 19. A man named Steven Gibbs invented it & claims that with this device one can travel in time. Google it.

Other that than, yes, I do think that it is possible. I don't have any real education behind what I believe, but I also believe in the Loch Ness monster, so go figure.

[atreidi]

I think that if someone would travel in time a new "PARALLEL REALITY" would exist leaving the original reality intact and changing the outcome of the new one.
Thats one of me theories.

[mattpoulsen]

Time travel in the future is not just theory...it has been experimentally proven...although very subtly.

In order to notice effects of time travel one must travel at speeds which are a considerable fraction of the speed of light. By doing so one may experience "time dilation."

In very simplistic terms, anything moving with respect to another object will have its time dilated with respect to the stationary object. This means that even at slow speeds a moving object experiences "time dilation" or a slowing of time, however at slow speeds the time gap is so small its completely unmeasurable.

If an object is in orbit (or anywhere for that matter) is moving at very very slow speeds when compared to the speed of light. I suppose if it orbited for 40 years you might be able to measure a tiny "time dilation" effect. I could calculate it, but won't bother right now. I'm guessing it would be less than a 1 second (if that) over a 40 year period.

In order for your experiment to work, the person would have to move at speeds near the speed of light to notice the effects you're suggesting. Obviously, speeds like that are entirely impossible right now, so it can't be done on things the size of baseballs and spaceships...at least right now.

However, the concept of "time dilation or the "slowing of time for a moving object" is not theory. It is something that has been verified repeatedly in particle physics. In fact, scientists who study fundamental particles have to correct for time dilation in order for things to "work out correctly" and actually use it very regularly.

I would also add that these effects, known as "relativistic effects" are something that are corrected for all the time in certain technologies. In fact, the military version of GPS must correct for relativistic effects which arise under the "general theory of relativity" in order for the system to be accurate. I won't get into "GR" because its quite a bit more complicated than "special relativity" (which is described by the moving object example). I'll just add that Einstein also showed that clocks run slower in large gravitational fields, but that's a different discussion.

[Prince of Lombards]

Originally Posted by mattpoulsen

Time travel in the future is not just theory...it has been experimentally proven...although very subtly.

A theory is an explanation for something that has been proven to occur.

Regarding the poll, I didn't vote. It is absolutely possible to travel through time at a different rate than another entity in a separate frame of reference, and even needs to be taken into account when making various computations related to manned space flight as well as the timing of out space satellites.

So, it is possible, and it's not a matter of technology because even when you run with your legs, time flows at a different rate than it does for somebody standing still watching you.

[mattpoulsen]

Yes, its a matter a degree. The point of the question though is asking whether or not space travel, in a noticeable sense, is possible. As I clearly stated, even at slow speeds time dilation occurs. But the point of the question is not to address these subtle effects...its to address time differences that are large enough for a human to notice.

That is absolutely a matter of technology.

I would also add your mixing the use of the word "theory." The way it was framed in the early posts it is clearly the layman's version of "theory." In science there are theoretical descriptions of expected behavior which are governed by things like "the theory of gravity" or the "theory of relativity." However, even scientists use the word "theory" to describe things that have been "done on paper" as opposed to things done by experiment. This latter description is clearly what the poster was suggesting.

Also, the correction made in satellites is due to general relativity not special relativity.

[HighPlainsDrifter73]

Originally Posted by rcsteiner

I'm travelling forward in time right now!

Were all stuck in a river of time flowing in one direction only. It's like a raging river with no way to get out. We are prisoners, for now.

Yes, time travel into the future is possible if you go a significant fraction of light speed. Going backwards in time, that's a completely different problem.