Thread: Would FTL Mean Time Itself Would Stop?

Einsteinian physics shows us that the faster something moves, the slower the effect time has on it. So someone traveling close to light speed would age slower than a person on Earth.

Now what happens if you go FTL? And I don't mean Alcubierre drive which avoids it with exotic matter which has not been proven to exist (negative matter).

I think you wouldn't even make it to FTL. Let alone light speed. But if you did somehow, I think time itself would stop. As that would be the only thing in Einstenian space preventing you from from traveling through time into the past.

So wanna live forever and NEVER age? Then go FTL. You won't age. Period. Unless you slow your speed down somehow.

It least that is what it appears to be.

Or perhaps aging time travel effect ONLY happens to the space craft? Meaning it would get younger and younger until it didn't exist, killing the crew inside once they reach outer space?

This kind of stuff makes your brain explode with all the possiblities.

Another odd possiblity is the takeoff of an FTL spaceship. Remember, it's going faster than light (much faster than light if it wants to get anywhere in reasonable amount of time).

Which means it will look like it's sitting still to an observer, even after it already took off. You could put your hand through it, and it would just be light (like a hologram).

Reason? The ship left before the light of it leaving could catch up.

Originally Posted by lorbo

wanna live forever and NEVER age? Then go FTL. You won't age. Period.

Yeah, but you won't be able to move or think either. You'll be stopped. Heartbeat, breathing, everything.

Subjectively, traveling near the speed of light is like the hyperspace we love in movies. Except that if you could observe a planet in passing, it would appear to rotate way too fast.

Originally Posted by Pong

Originally Posted by lorbo

wanna live forever and NEVER age? Then go FTL. You won't age. Period.

Yeah, but you won't be able to move or think either. You'll be stopped. Heartbeat, breathing, everything.

Subjectively, traveling near the speed of light is like the hyperspace we love in movies. Except that if you could observe a planet in passing, it would appear to rotate way too fast.

Yeah, I figured that from further research.

So provided you has some way to go a light year per hour (which is decent speed for getting places), Earth people would say you reached Proxima Centauri in about 4 hours. For you? Instant.

and if you reach light speed, your 4yr trip to the next star or even a million year trip through the galaxy would happen before your eye blinked (since everything from your perspective has stopped)

I think the more difficult part would be stopping. If somehow you obtained light speed, how would you stop? you could no longer push the stop buttion. An auto stop wouldnt work because the electrical signal could not travel to the kill switch. Run out of fuel (which brings in the issue of how the fuel continues to run to the engine at such speeds) seems to be the only option tho that makes a return trip very hard.

Not sure about traveling near the speed of light would be a viable option either as you would still be slowed down and be moving like a turtle.

Consider this, your on a ship traveling just under light speed. You then fire a gun. Will the bullet now be breaking light speed? It wouldnt, the bullet would appear to be hovering infront of you, almost barely moving.

Originally Posted by GoldenRatio

and if you reach light speed, your 4yr trip to the next star or even a million year trip through the galaxy would happen before your eye blinked (since everything from your perspective has stopped)

I think the more difficult part would be stopping. If somehow you obtained light speed, how would you stop? you could no longer push the stop buttion. An auto stop wouldnt work because the electrical signal could not travel to the kill switch. Run out of fuel (which brings in the issue of how the fuel continues to run to the engine at such speeds) seems to be the only option tho that makes a return trip very hard.

Not sure about traveling near the speed of light would be a viable option either as you would still be slowed down and be moving like a turtle.

Consider this, your on a ship traveling just under light speed. You then fire a gun. Will the bullet now be breaking light speed? It wouldnt, the bullet would appear to be hovering infront of you, almost barely moving.

Technobabble son. Technobabble.

If and when we find tachyons (theoretical particle that travels faster than light ALWAYS), and we have a way to trap it plus manipulate it, FTL will be a possiblity.

Barring revolutionary discoveries we have eternity to find through generations of future humanity? No way.

Actually you only have about 4billion years before the sun goes all red giant on you. Better be off this rock by then

Originally Posted by GoldenRatio

I think the more difficult part would be stopping. If somehow you obtained light speed, how would you stop? you could no longer push the stop buttion.

Lol good point. Even approaching light speed, your reflexes would be inadequate to the rate of space whooshing past.

Isn't FTL supposed to make time reverse? In that case you'd push the stop button prior to breaking the time barrier, so in retrospect you'd have no knowledge or record of that event.

Let's try to inject some real physics into this.

In the original post it said:

Einsteinian physics shows us that the faster something moves, the slower the effect time has on it. So someone traveling close to light speed would age slower than a person on Earth.

More correctly, It says that the higher the relative speed between two frame of reference, the slower each frame will measure time as moving in the other frame as compared to its own. If I pass you with our relative speed being 0.866c, I will measure your clock as running at half the speed of my own and you will measure my clock as running 1/2 the speed of yours. This is time dilation.

[/quote]I think you wouldn't even make it to FTL. Let alone light speed. But if you did somehow, I think time itself would stop. As that would be the only thing in Einstenian space preventing you from from traveling through time into the past.
[quote]

This is a unfounded assumption. The formula for time dilation is



V is the relative velocity between frames. T is the time measured by our observer and t the time for the frame moving at with respect to the observer.

As v approaches c, T becomes very large compared to t. T runs faster than t.

But note what happens if v=c. then t=1/0

1/0 is undefined. You can't really say that time stops at c, but that it is undefined at c.

If you increase v to greater than c, you get a result that is the square root of a negative number.

There are no square roots for negative numbers, so there actually is no answer for this scenario.

In other words Relativity cannot tell you what would happen if you to reach FTL speeds and expressively forbids it. Thus, when you even hypothesize what would happen at these speeds, you are hypothesizing about what would be if Relativity did not hold. Thus you cannot use Relativity to even try to guess as to what would happen. And it would be just that, a guess, with nothing to base it on. A pretty fruitless exercise.

Another odd possiblity is the takeoff of an FTL spaceship. Remember, it's going faster than light (much faster than light if it wants to get anywhere in reasonable amount of time).

Which means it will look like it's sitting still to an observer, even after it already took off. You could put your hand through it, and it would just be light (like a hologram).

Reason? The ship left before the light of it leaving could catch up.

Erm, no. Come on, think a little. Why would the light leaving the ship have to catch up? One instant there is a ship and light is leaving it and traveling to your eye. The next instant, there is no ship at that spot. After that you'll only see the ship for the brief time it takes for the last light that left the ship to reach your eye. To you, the ship is there and then it isn't.