Time Dilation

[everman]

I just stumbled across something very interesting called Time Dilation. Ex: If you travel at 90% the speed of light, 2.25 days elapses on earth for every day you travel. At 0.999999 it's 2 years on earth for every day you travel. I found some interesting stuff here.
So what does this mean for intergalactic travel? It's a little difficult to understand how it works but very interesting, anyone know more about it?

 

[Evadman]

It has been measured and observed on concorde jets. very cool stuff

 

[sao123]

Although Time Dilution is a measurable phenomenom, I am not yet convinced that it is real. It is measureable, yet because we change velocity through a reference of time and space, closer to the periodic pulse of an atom, mathematically it will seem to be measured that time has slowed down. It is quite possible that merely because of the frame of reference is changed the measurement is affected. Yet the process of aging stays constant. Because of our limitations, we cannot prove that aging or other processes actually deaccellerate with the measurement of time, thus prolonging life may still not be feasible.
IE... your body ages at a constant rate X then you Grey and Die. the measurement of time in normal velocity would indicate you have lived 30 years. Yet in the diluted time, it would appear you have only measured 3 days. (exadurated example, but conceptual nonetheless.)

 

[everman]

If traveling near light speed did actually slow aging as well, would that mean if you were to move at light speed you would be eternal? Of course there's other problems associated with traveling at that speed is infinite mass... But does that apply to all matter? Could there be something that would not have that problem?

 

[LordMagnusKain]

more importantly, could we set up stations to allow people to go on a time-voyage, a way for rich people to invest money, go on a cruse, and come back with a whole lot more money

 

[heliomphalodon]

Perhaps the most convincing example of time dilation has to do with very short-lived subatomic particles. You can look up the details, but the general idea is that a particle accelerator collision creates a short-lived particle that is moving at a large fraction of lightspeed. In the laboratory frame of reference, the particle appears to decay much more slowly than it would at rest. There is a similar effect having to do with cosmic rays striking atoms in the Earth's atmosphere -- some of the resulting particles are traveling fast enough that their decay is "slowed" sufficiently for them to reach the ground, which would ordinarily be impossible.

The usual gedankenexperiment has light bouncing from side-to-side in a fast-moving vehicle -- when this situation is examined, Einstein's postulate (that the speed of light is constant for all unaccelerated observers) leads directly to the time dilation effect.

 

[f95toli]

Originally posted by: everman
If traveling near light speed did actually slow aging as well, would that mean if you were to move at light speed you would be eternal? Of course there's other problems associated with traveling at that speed is infinite mass... But does that apply to all matter? Could there be something that would not have that problem?

No, YOU would still live a normal life, but the people OBESERVING you would see you live for a very long time, they would also see you move very slowly. The key concept here is frame of reference, time dillation occurs when two reference points move with a different speed. In each frame of reference time appears to be "normal".

 

[chsh1ca]

There were some experiments done with Cesium Atomic clocks on jets that travelled at Mach 1 or 2 (IIRC), and the clocks did get offset.

As f95toli said, the rules of relativity always speak in terms of frame of reference.

 

[f95toli]

Time dillation can also appear due to differences in the gravitational field (described by the General Theory of relativity). A familiar example is the GPS-system. It is compensated for time dillation, since the satellietes are in high orbit they will experience a slightly lower gravitaional pull than things on the ground and this needs to be compensated for, otherwise the indicated position would be wrong (I have heard the figure 100 m but I am not sure it is accurate).

The best atomic clocks are now so sensitive that they can detect (by comparing with another clock) how the ground moves up and down due to motions in the earth's crust (we are talking about a few meters each year).

The next generation of atomic clocks will probably be put in orbit to avoid this effect (it is quite likely that a test module will be installed in ISS), motion in orbit is much more predictable than the motion of the ground.

 

[dejitaru]

Relative time is more strongly affected when near a massy object.

 

[Broadkipa]

Time travel at near light speeds is a one way trip, there would be nothing to come home to . All your friends and family etc would be long gone. There may not even be an earth to come back too.

 

[rimshaker]

Originally posted by: Broadkipa
Time travel at near light speeds is a one way trip, there would be nothing to come home to . All your friends and family etc would be long gone. There may not even be an earth to come back too.

ahhhh...now we have to open up a new thread on time travel

 

[everman]

Maybe you just want to send something into the future, not a person. Although you're not sending it into the future really, But I think you know what I mean.