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Students Calculate What Hyperspace Travel Would Actually Look Like
cylonlover writes "The two Star franchises (Wars and Trek) and countless science fiction movies have given generations of armchair space travelers an idea of what to expect when looking out the window of a spaceship that's traveling faster than the speed of light. But it appears these views are – if you'll excuse the pun – a bit warped. Four students from the University of Leicester have used Einstein's theory of Special Relativity to calculate what faster than light travel would actually look like to Han and Chewie at the controls of the Millennium Falcon. The fourth year physics students – Riley Connors, Katie Dexter, Joshua Argyle, and Cameron Scoular – say that the crew wouldn't see star lines (PDF) stretching out past the ship during the jump to hyperspace, but would actually see a central disc of bright light."
There are two methods of FTL being talked about here, but they are conflating the two.
Traveling via "warp" means warping space and time itself so you're moving through space at less than C, but space is shrinking in front of you and expanding behind, so the net effect is that you've moved from point A to point B in less time than it would take light travelling without warping space. (Your actual velocity may actually be zero with this method.) This is how Star Trek does it (sort of).
Traveling via "hyperspace" means punching some type of hole in space and traveling "somewhere else". Sometimes it is just a wormhole between points A and B, but it is commonly (like in Star Wars and Babylon 5) some other space within or without normal space. It's a short cut.
Nerds should know this, and yet this is the second time within a week I've seen these two ideas talked about as if they are the same thing.
(I'll leave it to someone else to explain how traveling by Guild vessel works...)
The slashdot summary is totally inaccurate. It makes it sound as though the paper calculates what would be seen by an observer going faster than c relative to the stars, but actually the paper calculates what would be seen by an observer going at v=0.9999995c.
There is also basically nothing new in this paper. The effects they describe (relativistic aberration and Doppler shifts) have been well understood for a long time. ANU has made a nice educational video showing these effects.
The question of how things would look if you could go faster than c relative to the stars is a whole different issue. Special relativity doesn't forbid relative motion faster than c, but it puts a bunch of constraints on it: (1) it can't be achieved by a continuous process of acceleration from velocities less than c; (2) if it exists, it violates causality; and (3) although special relativity is consistent with the existence of faster-than-light particles (tachyons), it is not consistent with the existence of faster-than-light observers in a universe with 3 spatial dimensions and 1 time dimension, a.k.a. 3+1 dimensions. Result #3 (no tachyonic observers in 3+1 dimensions) has been known for a long time, but it seems to keep getting rediscovered.
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Big and hairy. Actually, a lot like your mom - but with better outdoor survival skills.
Is it just my observation, or are there way too many stupid people in the world?
You wouldn't see anything at FTL speeds as even radio waves would come on as gamma radiation. If that doesn't kill you outright you can expect your clothes to no longer fit and your tan to turn a darker shade of green whereupon you smash the controls and die anyway.
Power tends to corrupt, and absolute power corrupts absolutely.
The link is slashdotted, but if this is the story I read earlier today then they didn't do either. Instead, they figured out what it would look like at just below light speed... about 99.995% of c.
In a nutshell, it's all about the Doppler effect. Normally visible objects like stars are blueshifted into the X-ray spectrum and the only visible is the cosmic background radition, which just looks like a big blur as it's blueshifted into the visible spectrum.
...is broke. Usually when you prove a theory wrong through evidence, it gets put away in a box. Not Special Relativity, it gets bandied about as being the most wonderful thing, we'll just modify it a little to make it work...
Einstein did modify it. The resulting theory is called General Relativity. Special Relativity still works as an extremely accurate approximation in the absence of strong gravitational fields. The equations of Special Relativity are used in experimental high energy physics all the time quite successfully.
If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
Newton's law of gravity is broken as well. The thing is that although it's inaccurate and broken, it's a really easy approximation to how gravity works that gets you results that work well enough that people still use it for most situations. SR is similar, it doesn't work in non-inertial frames but with inertial frames, it's good enough in most situations and a lot easier to use than GR.
"When you sit with a nice girl for two hours, it seems like two minutes. When you sit on a hot stove for two minutes, it
I giving all she got captain and I don't get the lines.
Nothing. You would see absolutely nothing. Blackness. Empty space. Here is why:
The warp field used to push the ship would be a 100% metamaterial, which redirects all particles, including light, around the ship perfectly, and or, capturing the particles on the event shock, and preventing them from reaching you.
That's the problem with cheating by removing the ship from the causally connected universe, via a albucuierre warpdrive; being no longer causally connected means you can't see anything, because you stop interacting with the universe outside the warp field.
Ok, pedantically, you would see an insanely redshifted image of the universe you left behind, instead of empty space. But to human eyes, that heat map would appear literally black.
When you rupture the field, and spill back into being causally connected with the universe at the remote reference frame, a shitton of energy and radiation will blast out.
Piloting a ship with that kind of propulsion would require very precise calculations about the passing of local time inside the warp field, and the time frames of both site of departure, and site of destination. It would be impossible to measure spacial distance, so the unpredictable unit of variable time is all you would have to work with. Long distance navigation would be an almost absurd proposition due to this fact. This could be the fly in the ointment against this form of travel in fact.
The actual geometry of a wormhole is too peculiar for most viewers, so "zipping really fast across the galaxy! Wheeeee!" Is more familiar. It's a TV show. Lighten up fancis.
Really, an actual wormhole would resemble a sphere in 3d space, through the center of which, you see straight through out the other side of the companion spherical appearing disruption at your desintation. The "edge" of the sphere would look mirrory, and highly distorted. Traveling into the wormhole on any sufficiently oblique trajectory would be "a bad thing(tm)". It is this oblique interaction that is hypothesized to make any artificially stabilized wormhole rapidly become unstable, as particles get caught in tight "circular" loops and literally feedback the wormhole shut.
None of this "disc shaped portal" nonsense.
Because that would be mindfucking to most viewers, special effects people make wormholes flat, for fragile human minds.
And even so, theorists were very enthusiastic about trying to modify SR accomodate the superluminal neutrino results from 2011. Unfortunately those results turned out to be due to a loose cable.
Yep, and that's a very good thing indeed. It's when science becomes dogmatic that we should worry. Taking results in contradiction with models and attempting to modify the models so that the results fit is how science works. Sometimes you can make the models work, sometimes you need entirely new models, and sometimes it's something in between.
Incorrect. Things appear to be moving at a speed that is faster than light, but they are in fact moving at a speed below that of light, and it is space itself which is at the same time expanding, causing the effective distance between those objects and us to grow at a rate which exceeds the speed of light.
They do not however travel at FTL speeds.
No, it means that at most, you might be able to send a message through a wormhole as a beam of light precisely send exactly at the exact computed centerpoint of the sphere, and very little else.
Sending a human through the wormhole would have a sizeable number of the human's atoms entering on trajectories that don't precisely intersect the sphere's centerpoint, meaning the shearing effects of the wormhole would rip the human apart. They would come out the other side as a spray of microparticulates. (And if entering highly oblique, would turn into a fireball of radiation whirling around the edges of the wormhole.)
It is possible that with a sufficiently "large" wormhole, the shearing forces would be sufficiently diffused over a large enough entry window to permit a human sized object, but the wormhole would have to be fucking enormous. I mean. Fucking. Enormous. The human would still experience radical compression and shearing forces, but they would be below the energies needed to tear the human apart. That doesn't mean the experience would be in any way "enjoyable."
Atmospheric gasses interacting with the wormhole's event horizon? Hoooboy... can you say nuclear fireball? No. Travel through a wormhole would require as close to absolute vacuum as possible, a fucking enormous wormhole, and a pair of depends diapers, because you are gonna need em.