A Question for All You Sciency Types

[Adam Jensen]

So as we all know, by our current understanding of physics, it is impossible to accelerate to the speed of light, which is a complete and utter disappointment to science fiction fans all across the globe. But as I was watching Star Wars the other night, watching the Millennium Falcon go into hyperspace and the stars going into star lines and then a strange blue and black mottling, I began to wonder just what going past the speed of light would look like. After all, we'd be going faster than the light reflecting off any object we'd see.

Imagine then a spacecraft that can exceed the speed of light, for some strange law of physics that still eludes us, and that our ship is crafted such that it and its occupants are protected by the immense g-forces caused by such an acceleration. What would we see if we looked out the cockpit?

[Grizzly Willy]

Would have to imagine that you would either see things going in reverse since you're moving faster than the light is reaching you.

[Deleted]

You would, like, go back in time, man.

[checking facts]

I'd imagine you wouldn't see anything since the speed of the light is way ahead the maximum speed the human eye can see stuff lol

[Catta]

id imagine the stars would seem blueish due to the doppler effect (cant remember if theres a different word for the light waves) But if it is supposed to travel faster than light they are prolly bending space around them so i guess it would look like that

[arden714]

I think if anything we will find out how to bend space/time to possibly travel faster than light. I don't think there is any technology that could produce enough energy to accelerate something the size of a car let alone a spaceship to the speed of light.

The interesting thing is how fast objects in the universe are travelling. Obviously the forces that were generated to create those speeds are absokutely unobtainable, its highly likely that our galaxy is moving near the speed of light away from the center of the universe. Which is obviously a lot more mass than a photon or proton.

I'll be happy if we can begin sending humans to other celestial bodies in our solar system in my life time

[smelltheglove]

as i understand it - i could be very wrong here - most theories regarding FTL travel involve "cheating" the system to get around the speed of light, not butting one's head against it. star wars used one theory, that of entering "hyperspace", basicly another dimension where one could travel faster than light relative to one's own dimension. another dimension could look like anything i guess, no way to know really.

star trek used "warp" technology, creating an artificial bubble around the ship, and that process allowed faster travel. it is a legitimate theory that i havent explained well at all. my guess on that is that the show's portrayal is fairly accurate in the forward view, but not so sure about the rear view. going toward a light source wouldnt affect its visibility, regardless of your speed (im guessing), but stars viewed in the rear view mirror? how would the light catch up, it's heading the same direction as you. not sure how this would work out really :/

well, that's my steaming pile of theoretical bullshit, lol

[Grizzly Willy]

I'd imagine you wouldn't see anything since the speed of the light is way ahead the maximum speed the human eye can see stuff lol

Have to remember that your speed is relative to everything else. You going 1% faster than the speed of light would, presumably, show everything moving backwards at 1% the speed of light, since your eyes would still be receiving light, and the light is still traveling at the same speed it always is.

Of course, this is all assuming that the objects at hand are things that are extremely far away, like stars. Anything close enough will have gone by too quickly for you to pick up any visual data.

Also, I would just like to clarify: I am by no means an expert in physics, let alone the mechanics of FTL travel.

[Crunkshock]

You would see nothing, directly behind your path of travel at least, as light cannot move fast enough to catch up to your retina. However, when your vehicle stops, the light will catch up. If you were traveling for 1000's of years in one direction, and had some sort of super telescope on board, you could theoretically watch planetary systems move from where they were in the past to where they are at the time the vehicle stopped.

[Deleted]

Why not put a fan behind my lamp and turn the lamp on and watch the Universe unfold around me?

[Rendia]

The way I always saw the "tunnel of blue-black mottle" was basically a wormhole effect. They aren't actually going faster than light speed, they are "folding" through space.

[Sterilize]

So as we all know, by our current understanding of physics

May not be too far out of the realm of possibility.
http://www.popsci.com/technology/art...g-consequences

I imagine it would be similar to what you see in something like star wars. My knowledge of photons is somewhat limited though - are they visible if they're not reflecting off of anything <ie atmosphere>?

Video somewhat related.

[Deleted]

Well, pretty easy: the Doppler effect would still apply. You wouldn't be able to see anything when looking out the back of the spacecraft, but when looking out the front window of your cockpit, you'd pretty much simply see a much "blue-er" version of whatever else you would see. It works pretty much the same way as with sonic waves being affected by the high velocity of fast moving vehicles.

The only difference would be the form of the "barrier" itself. While the sound barrier is build up via air compression and imposes difficulties of technical and aerodynamic nature in the first place (extreme forces affecting the wings and control mechanisms and rather big changes concerning air-pressure), the barrier preventing spacecraft from accelerating to the speed of light (or even beyond it) are more fundamental in nature. Such as the mass of the vehicle and therefore the energy needed to accelerate it further growing with it's speed. As there is basically no experimental data for anything exceeding the speed of light, it is impossible to say whether it can be achieved or what would happen if it would be achieved.

My guess would be, that there would be much more fundamental changes within the behavior of the vehicle (and maybe even it's nature) than there are when exceeding the speed of sound. It might even be possible that anything being accelerated beyond the speed of light loses it's material component or whatever. Really... difficult to describe what would or could happen, even more difficult to make up theories with any scientific base for it.

[Beavis]

http://www.youtube.com/watch?v=3kSyb...Ai0&feature=iv

Here you go. Go to 1:20ish for the answer.

[Symphonic]

Let's say you were going directly towards the sun. As you approached the speed of light the sun would look like it's getting smaller because you're "catching up" to the light that had previously been behind you. In fact, you'd probably be able to see the back of your head as you get caught up to the traveling speed.

[Deleted]

Like that.

[Jiraden]

A little confused by the people stating you wouldn't see anything. Once the area is already illuminated, wouldn't it not matter how fast you were traveling, as the illumination already occurred? It would be different if you were in pitch darkness, and you accelerated and then somebody turned on a light source and you were to race against it, but in this case I'd imagine it wouldn't be pitch black, simply because the illumination is already there. Now, what it would actually look like is a completely different question, I'd imagine everything would be a streak as your human eye wouldn't be able to keep up with the objects.

[MerinPally]

I imagine it would look like the animation on the right hand side of this webpage - the image of the proposed path of the Tachyon.

http://en.wikipedia.org/wiki/Tachyon

2 images and the Cherenkov Radiation shockwave.

Cherenkov Radiation, in simple terms, can be summarized as follows:

Whilst the top speed of light is at a maximum, it can be slower, which is why it appears to bend at times. When that slowing down bit is large enough that when the radiation from any charged particle hits it, energy is lost, which is emitted as Cherenkov Radiation. That kinda sums up the link in the diagram about it because it will talk about wave propagation.

PS think I got the image working:

http://en.wikipedia.org/wiki/File:Tachyon04s.gif

[Kasierith]

I would assume that, if you look back, the radiation that makes up light is going to be moving slower so it won't be able to reach your eyes.... so you'll see absolutely nothing because you're essentially looking into your own shadow. Light that is in front of you, moving relatively slower than you are, will bounce off, scattering in other directions instead of going to where you are looking at, which is on the other side. I imagine that if you looked forward, you would see things in fast forward, though honestly if you're moving at more than the speed of light, by the time you actually see something other than stars you'll have crashed into it. Light travels faster than the electrical transmissions from your rods/cones to your brain

[Boldwyn]

We don't really know. But even going near speed of light would be quite trippy: