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

[drewid]

Given this thread is about whether or not time dilation = time travel it must be assumed for the sake of the argument if nothing else that time dilation is at least possible. I haven’t argued that time dilation isn’t time travel because time dilation isn’t possible. My purpose is to argue that time dilation isn’t time travel and I don’t see that how the time dilation may be achieved is important. If we say that one twin enters a magic room that causes time dilation and slower aging then that’s fine by me.

So one twin enters the magic room and ages at half the rate of the other twin. When the twin leaves the magic room s/he is half the age of the other and they then continue aging at the same rate. I don’t see any time travel

Let's push that a bit.
Say you entered a box for five minutes and came out fifty years into the future would you call that time travel?

If it was you going into the box then you'd call it time travel (albeit non-reversable), if you were the twin outside the box waiting then you'd call the box a "Slow Time envelope" or something. It literally depends on your point of view.

 

[sol invictus]

Just out of curiosity, does anyone think anything I’m saying has any merit (even a tiny bit)?

I'd say it does in the sense that "time travel" is a pretty ill-defined term. It's easy to get confused and argue about things that don't make sense in the first place. That's why no one can say "you're wrong that time dilation isn't time travel", because it's really a matter of how you decide to define time travel, and there's no particularly good way to do that.

But I think for a lot of people (including me), the notion of a box that you step into, feel little or no time pass, and step out of again long in everyone else's future - that sounds a heck of a lot like a time machine to me. I guess usually in fiction the box somehow doesn't exist at all during the intervening times, which makes this (or suspended animation) not quite like fictional time travel (plus the fact that you can't go back in time). But still, as far as subjective experience goes it's identical.

As far as my river analogy goes, it seems like you're missing the point of analogies, which is to make them different from the actual thing in question, but still similar in some respects. In the analogy distance down the river is time.

 

[surrogate]

Just out of curiosity, does anyone think anything I’m saying has any merit (even a tiny bit)?

I can understand your point about not defining time dilation as 'time travel'. Time manipulation might be a more accurate way of describing it. The end result is that the speedy traveler ends up further into the future of the clock on earth than he/she would have had they stayed home.

No, but that has nothing to do with the scenario I outlined.

Clocks A and B are in “normal time” and both read September 25 2013.

Clock A travels to “dilated time” and runs slower than clock B.

When clock B ticks over to September 26 2013 clock A still reads September 25 2013.

So “normal time” is September 26 2013 and "dilated time" is September 25 2013.

If clock B then also enters “dilated time” (together again with clock A) it has gone from September 26 2013 back to September 25 2013 (even though it reads September 26 2013).

I think that the problem with the above is that you are comparing clock B to clock A instead of both clocks to a reference clock in "normal time". All clocks are traveling into to the future of "normal time", just at different rates.

 

[theprestige]

Just out of curiosity, does anyone think anything I’m saying has any merit (even a tiny bit)?

Not yet. What merit do you think it has?

It doesn't have physical merit, because physicists don't call time dilation "time travel". They call it "time dilation" and rightly so. And your acknowledgement that time dilation might be possible doesn't have much merit, since we know that from observation that it is in fact not just possible, but actual.

And it doesn't have literary merit, because what literary merit could it possibly have? I mean, congratulations, you've just told Joe Haldeman that the main character of his novel, The Forever War, who traveled far into the future, did not experience "time travel" because he made the journey via time dilation effects--effects which are a known physical fact, by the way.

But what's the merit in that?

ETA: I would find merit, perhaps, if you answered a question I asked earlier: "what would you say is the most notable article that you have read in the past three years, that conflates time dilation with time travel?"

If you could give a specific example of the claim you are refuting, that would help me greatly understand whether your refutation has merit. You must have seen the claim at least once, before starting this thread, otherwise you wouldn't have known to start this thread to refute it. So what is the most notable example of the claim that you can think of, outside of this thread?

 

[dafydd]

Just out of curiosity, does anyone think anything I’m saying has any merit (even a tiny bit)?

No merit, just a semantic quibble.

 

[mijopaalmc]

Yep, in theory you could tell the difference between a cryonic suspended animation time traveler and relativistic time dilation time traveler by carbondating a hair sample.

Can radiocarbon dating accurately determine the age a living organism?

I thought radiocarbon dating more percisely determined the date of death for organic material.

 

[Brian-M]

Can radiocarbon dating accurately determine the age a living organism?

I thought radiocarbon dating more percisely determined the date of death for organic material.

You can't use radiocarbon dating to determine the age of living organisms, because living organisms are constantly ingesting new carbon-14, so the ration of carbon-12 to carbon-14 remains approximately constant.

But because hair is dead and the decaying carbon-14 in the hair is never replaced, you can tell how long ago a piece of hair was grown.

If you try radiocarbon dating the hair of someone who traveled 100 years into the future by time dilation, the hair would barely show any age at all, no different from anybody else's hair.

But if you try radiocarbon dating the hair of someone who traveled 100 years into the future by cryogenic freezing (assuming that they haven't been unfrozen long enough to need a haircut), the hair would show up as being 100 years old, because it was sitting in deep-freeze for a hundred years.

 

[Tomblvd]

How about, time dilation is not identical to being teleported into the future using a Star Trek transporter?

NO, everybody knows that transporters aren't used for time travel, they're used for transportation. You have to find a temporal rift, wormhole, Devidian portal, befriend a Q, etc. in order to actually time travel. SEESH.

;-) (just thought I'd get that in before ynot....)

 

[Brian-M]

NO, everybody knows that transporters aren't used for time travel, they're used for transportation. You have to find a temporal rift, wormhole, Devidian portal, befriend a Q, etc. in order to actually time travel. SEESH.

;-) (just thought I'd get that in before ynot....)

But Scotty used a transporter to send himself to the future!

When he retired from Starfleet in 2294, he was traveling aboard the U.S.S. Jenolen to his new home home in the Norpin Colony, and the ship crashed with him the only survivor. He put himself in transporter loop to keep himself alive until rescue arrived, which wasn't until the remains of the ship were discovered by The Enterprise (under the command of captain Picard) in 2369.

So he effectively used the transporter to send himself 75 years into the future.

(No, I didn't have all this memorized. I vaguely remembered the episode of The Next Generation where they found Scotty preserved in the transporter, so I looked up the details.)

 

[Tomblvd]

But Scotty used a transporter to send himself to the future!

When he retired from Starfleet in 2294, he was traveling aboard the U.S.S. Jenolen to his new home home in the Norpin Colony, and the ship crashed with him the only survivor. He put himself in transporter loop to keep himself alive until rescue arrived, which wasn't until the remains of the ship were discovered by The Enterprise (under the command of captain Picard) in 2369.

So he effectively used the transporter to send himself 75 years into the future.

Good point Brian, but I think we've determined that spending time in suspended animation (which is what a transporter time loop actually is) isn't true time travel.

Maybe ynot can weigh in on the transporter-loop-as-time-travel dilemma.

 

[psionl0]

NO, everybody knows that transporters aren't used for time travel, they're used for transportation. You have to find a temporal rift, wormhole, Devidian portal, befriend a Q, etc. in order to actually time travel. SEESH.

Which doesn't exactly invalidate my post.

But just to be more accurate, time dilation is not the same as finding a temporal rift, wormhole, Devidian portal, befriending a Q etc.