FTL Drive Effects

[shynung]

I'm going to use a KSP example here, hope you don't mind.

Suppose the Kerbals built an interplanetary manned spacecraft that had an Alcubierre drive onboard. This drive is able to translate the spacecraft at 3 times the speed of light, but needs to be charged slowly over a day.

The spacecraft was to depart to Jool orbit at exactly 1.00 AM the next day. At that moment, the distance between Jool and Kerbin is around 1 light-hour(light takes an hour to go from Kerbin to Jool). Since the Alcubierre drive enabled the spacecraft to travel at 3c, the journey time is expected to be 20 minutes, from the spacecraft's perspective.

At 1.00 AM, the spacecraft launched itself to Jool, and arrived there at 1.20 AM.

My questions are:

1. If the moment the spacecraft deactivates the warp drive, it deployed a telescope and aimed it at Kerbin, would it literally see an image of itself, still charging the Alcubierre drive, which disappears after 40 minutes?

2. If the KSC happened to be in view of both the spacecraft and Jool at the time of launch, would it see the spacecraft disappears completely at 1.00 AM, and suddenly appearing at Jool at 2.20 AM?

3. If a space station orbiting Jool happened to be in view of both the spacecraft and Kerbin at the time of launch, would it see 2 spacecrafts, one suddenly appearing at 1.20 AM, and the other still orbiting Kerbin, which disappears at 2.00 AM?

4. If another spacecraft orbiting Kerbol was close enough to the mid-point of the FTL trajectory of the travelling spacecraft, what would it see?

[R0cketC0der]

1. Yes

2. Yes

3. Yes

4. It would see the ship disappearing from kerbin at about 1:30 AM and appearing at Jool at about 1:50 AM. I'm not sure whether it could see the ship in flight, but if it would see it first when it was closest to it and then it would see it going into both directions at once. Also it would still see the orbiting ship at kerbin, so it would see the ship up to three times at once.

[The Destroyer]

That's really cool. And creepy. Time travel basically!

[KvickFlygarn87]

That's really cool. And creepy. Time travel basically!

I s'ppose that it's got something to do with relativity.

[vexx32]

It's not really time travel, it's just what happens when you move faster than the fastest thing in the universe -- the rest of the universe has to catch up.

[shynung]

4. It would see the ship disappearing from kerbin at about 1:30 AM and appearing at Jool at about 1:50 AM. I'm not sure whether it could see the ship in flight, but if it would see it first when it was closest to it and then it would see it going into both directions at once. Also it would still see the orbiting ship at kerbin, so it would see the ship up to three times at once.

It would see 3 ships?

[R0cketC0der]

It would see 3 ships?

Yes, one in kerbin orbit, one between it and Jool and one between it and kerbin.

[Dodgey]

Man I love hypertheicals!

[Scotius]

Yes, one in kerbin orbit, one between it and Jool and one between it and kerbin.

IF you would be able to see ship in FTL at all.

[rtxoff]

My Theory:

1->No

2->No

2->No

All light emitting from a craft in a warp field would be affected by this warp field too. So basically the light will travel faster then light inside the warp field so no to 1 and 2 and 3.

4 Probably human eyes would not see anything or to be more precise the brain would not register it. Some sort of high speed camera might record the ftl flyby however the recording timemark could be offset with the real position of the craft on that timemark.

[Tex_NL]

In Star Trek this would perfectly describe the Picard Maneuvre

[Tw1]

My Theory:

1->No

2->No

2->No

All light emitting from a craft in a warp field would be affected by this warp field too. So basically the light will travel faster then light inside the warp field so no to 1 and 2 and 3.

4 Probably human eyes would not see anything or to be more precise the brain would not register it. Some sort of high speed camera might record the ftl flyby however the recording timemark could be offset with the real position of the craft on that timemark.

The thing is though, those events took place before and after the warp field was deactivated. Even though it's not possible to see the vessel in flight, light will be reflecting off it before and after it goes into warp.

[rtxoff]

To number 1. The warpfield streches behind and infront of the craft,also the light after the warp you are expecting to see won't be there because it is in the path of the vehicle. There is no chance for the light from the past to arrive without beeing disturbed by the craft itself. Only possibility maybe if the vehicle warp in a curve... But that can be deadly as we know from Star Trek :-D

So 1 still no. Also after the warp, the same duration the warp travel took there should be no light at all incoming from the departure direction so just a black hole visible or not visible because you can't see something that is not there ^^

2 3 and 4 i need to rethink

indeed... that is a though nut

[Technical Ben]

That's really cool. And creepy. Time travel basically!

You can see yourself in a mirror. Technically your past self also. It's not a problem.

The problem with "travel faster than light", is as humans we don't understand the question in the first place. "What does it mean to go faster" is the wrong question is seems. As both time and space in this instance are related, we get stuck at a point we cannot "go faster". Though most of us (me included ) first just think "but can't we just add one more bit to our speed?"