Time Dilation = Time Travel? – I don’t think so.

[ynot]

Then by your definition, time dilation is not time travel.

End of thread?

Care to give your definition in which I assume time dilation is time travel? Would you also define suspended animation as being time travel?

 

[icerat]

Earth time is the standard against which possible time travel is being measured and is the time that it's being claimed is being traveled to the future of. The person travelled for 100 years of Earth time and rejoined Earth time after 100 years of Earth time. The traveller never travelled ahead of Earth time in any time. A period of dilated time suspended animation compared to Earth animation.

So for time travel to occur, the person has to remain in the same time reference?

This seems nonsensical to me, so please elaborate.

 

[psionl0]

Care to give your definition in which I assume time dilation is time travel? Would you also define suspended animation as being time travel?

If you are on earth at a particular place and time then one hour later you are at the same place but 100 years in the future, why would the method you got there determine whether you traveled through time?

 

[Pup]

No..... If you get in a machine go flying for an hour and come back to Earth and 100 years has passed................ That's time travel.

That's almost exactly the scenario in the novel that gave us the phrase "time machine" and started the time travel genre: H. G. Wells' The Time Machine.

http://www.fourmilab.ch/etexts/www/wells/timemach/html/timemach_chap3.html

I drew a breath, set my teeth, gripped the starting lever with both hands, and went off with a thud... The night came like the turning out of a lamp, and in another moment came to-morrow. The laboratory grew faint and hazy, then fainter and ever fainter. To-morrow night came black, then day again, night again, day again, faster and faster still.

Whole passage here:
http://www.internationalskeptics.com/forums/newreply.php?do=newreply&p=9504561

The main difference is that after visiting earth thousands of years in the future, the time traveller was able to return back to his own time. But time dilation would produce the same result as his time machine that took him into the future.​

 

[ynot]

If you are on earth at a particular place and time then one hour later you are at the same place but 100 years in the future, why would the method you got there determine whether you traveled through time?

[FONT=Verdana, serif]From the perspective of Earth time you were away for 100 years not 1 hour. Earth time might perceive that you had travelled backwards in time as you are much younger than you should be for your Earth age. Or it might perceive that you have merely aged slower than the rate of normal Earth aging. Why is your perspective any more or less valid than Earth time perspective?[/FONT]

[FONT=Verdana, serif]If you were placed in suspended animation for 100 years and were then reanimated without having aged, would this determine that you had travelled through time?[/FONT]

 

[ynot]

So for time travel to occur, the person has to remain in the same time reference?

This seems nonsensical to me, so please elaborate.

[FONT=Verdana, serif]No - but to say one time has slowed down rather than the other time has sped up you have to use a particular time reference as a control standard. Did your time slow down relative to theirs, or did their time speed up relative to yours? [FONT=Verdana, serif]If aging slower due to time slowing down is travelling into the future then is aging faster due to time speeding up travelling into the past?[/FONT]
[/FONT]

[FONT=Verdana, sans-serif]Person A orbits the Earth at a high speed in a spacecraft and experiences time dilated to half of Earth time. A communicates with person B on Earth via a video link. A observes that B ages twice as fast and B observes that A ages half as fast. Neither have traveled to the others past or future.[/FONT]

 

[Roboramma]

If aging slower due to time slowing down is travelling into the future then is aging faster due to time speeding up travelling into the past?

No, it would travelling to their future more slowly than they are.

 

[Toontown]

Just think of the twins as wind-up clocks in the process of running down. The more quickly they tick (relative to a reference clock on earth), the more quickly they run down (age), and vice versa.

The traveling twin ticks more slowly (relative to the reference clock(and the earthbound twin)), and so runs down (ages) less than the other twin during an arbitrary number of ticks of the earthbound reference clock. The traveling twin doesn't notice anything odd because everything else in his spacecraft is also moving more slowly.

That is all that happens. They tick at different (relative) rates, and so wind down (age) at different rates relative to each other. Time is nothing more or less than relative rates of movement and/or change.

End of thread?

 

[psionl0]

[FONT=Verdana, serif]From the perspective of Earth time you were away for 100 years not 1 hour.[/FONT]

What difference does that make?

 

[Brian-M]

BTW.... can scientists do the math on this?

Can scientists say that if you travel at ..... I guess near the speed of light or as close as we can think we can get..... for a certain distance and then come back to earth... at what ever speed, that you are x amount of time in the future?

Put another way.... I want to go a hundred years in the future... but only be 1 week older.... Can anyone tell me how far and how fast I would need to go?

Do I travel in a circle? A straight line? Does it matter?

In practice it doesn't matter, because the the amount of acceleration needed to get to those kinds of speeds in such a short time would leave you as nothing more than a thin smear of red goo on the floor of your spaceship.

ETA:

In answer to your question, in order for for 100 years to pass on earth while only one week passes for you, you'd have to be slowed down by a factor of 5200. This means you'd need to be traveling at:

0.9999999815088756 C​

I got this figure from here: http://www.1728.org/reltivty.htm?b0=5200

 

[jasonpatterson]

[FONT=Verdana, serif]If you were placed in suspended animation for 100 years and were then reanimated without having aged, would this determine that you had travelled through time?[/FONT]

You keep asking this, and I didn't see any responses, but from the point of view of the person who is in suspended animation, yes, of course it would be time travel. They went to sleep and woke up 100 years later without any personal or biological time elapsing for them.

I would define time travel as being able to be present in the past, present and future concurrently. In other words the past and the future would have to be able to become the present for the time traveller.

I'm not sure what you're really looking for here, to tell the truth. It seems like you've defined time travel in a way that makes time travel impossible, as some sort of simultaneous existence at multiple points in time. If instead we go with the second sentence, which gives a rather different definition of time travel from the first, then it's entirely consistent with both time dilation and suspended animation being considered time travel. In both cases the traveler does something and after a period of personally experienced time arrives in a world in which a greater amount of time has passed.

If I could step into a machine and push a big red button that said FUTURE, then some lights flashed for 10 seconds or so and the next thing I knew I was standing in the same machine 100 years in the future, how is that any different from a flashy-light machine that could put me in suspended animation in 10 seconds followed by being revived in 100 years? From my point of view nothing different happened.

 

[ynot]

Instead of twin A leaving Earth time for 1 hour of dilated time then returning to Earth time, let’s consider a scenario where twin A leaves Earth time then after 1 year of Earth time twin B also leaves Earth time to be in the same dilated time as A. If one hour of dilated time equals 1 year of Earth time then twin B would be almost 1 year older than twin A. Does that mean twin A has travelled into twin B’s past, or that twin B has travelled into twin A’s future? I think neither.

 

[ynot]

In practice it doesn't matter, because the the amount of acceleration needed to get to those kinds of speeds in such a short time would leave you as nothing more than a thin smear of red goo on the floor of your spaceship.

ETA:

In answer to your question, in order for for 100 years to pass on earth while only one week passes for you, you'd have to be slowed down by a factor of 5200. This means you'd need to be traveling at:

0.9999999815088756 C​

I got this figure from here: http://www.1728.org/reltivty.htm?b0=5200

End of thread?

Or do we keep playing let's pretend?

 

[ynot]

You keep asking this, and I didn't see any responses, but from the point of view of the person who is in suspended animation, yes, of course it would be time travel. They went to sleep and woke up 100 years later without any personal or biological time elapsing for them.

I find it hard to accept that traveling through time or not could be subject to a point of view.

I think it’s a mistake to look at time travel as if it’s a human experience rather than a possible or not reality.

 

[Toontown]

You keep asking this, and I didn't see any responses, but from the point of view of the person who is in suspended animation, yes, of course it would be time travel. They went to sleep and woke up 100 years later without any personal or biological time elapsing for them.

But time did elapse. The suspended person simply was not aware of it's passage. And there is no such thing as "biological time". Hypothetically, the biological processes and attendant increasing entropy of a biological system might be suspended or slowed. However, time passes normally during the suspension.

And now I'm going to time travel...er, I mean sleep.

 

[Pup]

I find it hard to accept that traveling through time or not could be subject to a point of view.

But traveling through space is subject to a point of view. Edited to add: I mean in exactly the same sense. If I drive past a standing person, we only subjectively "know" which one is moving. According to the theory of relativity (if I'm understanding it correctly), one could say that the driving person is motionless while the standing person slides past him.

 

[Toontown]

But traveling through space is subject to a point of view. Edited to add: I mean in exactly the same sense. If I drive past a standing person, we only subjectively "know" which one is moving. According to the theory of relativity (if I'm understanding it correctly), one could say that the driving person is motionless while the standing person slides past him.

You could do that, by adopting a frame of reference in which the universe is rotating about the center of Earth and the vehicle was in co-motion with it when the speedometer read 0. And now the universe is rotating about the center of Earth at a velocity precisely consistent with the velocity shown on the speedometer.

But you know you'd just be kidding yourself.

 

[icebear]

The little club comprising authors of dead theories from past centuries has more than one member, i.e. it' not just Chuck Darwin, Albert Einstein is a member of that club as well. There is no physical basis for time travel.

 

[ynot]

If I could step into a machine and push a big red button that said FUTURE, then some lights flashed for 10 seconds or so and the next thing I knew I was standing in the same machine 100 years in the future, how is that any different from a flashy-light machine that could put me in suspended animation in 10 seconds followed by being revived in 100 years? From my point of view nothing different happened.

If you truly travelled in time you wouldn’t exist in the departure/arrival time frame for the 100 years of your time travel. You would skip 100 years. If you were merely in suspended animation however you would exist in that time frame for the full 100 years. Pretty much what Toontown said . . .

But time did elapse. The suspended person simply was not aware of it's passage. And there is no such thing as "biological time". Hypothetically, the biological processes and attendant increasing entropy of a biological system might be suspended or slowed. However, time passes normally during the suspension.

If not being aware that time has passed is time travel then sleeping is time travel.

And now I'm going to time travel...er, I mean sleep.

 

[ynot]

The little club comprising authors of dead theories from past centuries has more than one member, i.e. it' not just Chuck Darwin, Albert Einstein is a member of that club as well. There is no physical basis for time travel.

Not sure I understand your post, but do you think there is any basis for time travel? Do you think time dilation would be a basis for time travel?

Welcome to the forum.