Nov29
Warp Drive
on November 29, 2012 at 9:29 amWhat if NASA could figure out the math?
Well, Alpha Centauri in two weeks is nothing to sneeze at. Of course, this could be a problem:
…other scientists have raised concerns that warp drive could be potentially very dangerous, potentially destroying the destination in its path.
Luddite whiners, standing in the way of progress.
They linked this article describing a powerful burst of radiation that would be emitted when a ship “dropped out of warp drive”. That piqued my interest. We could be trying to look for such a signal as evidence that we are not alone, and that the aliens already have warp drive. Sounds like a good plot for the next alien invasion movie.
http://www.universetoday.com/93882/warp-drives-may-come-with-a-killer-downside/
Interesting paper, and hey, I got the impact issue right with just a simple thought experiment.
There’s probably a simple fix to the radiation burst issue they raise, which is to periodically oscillate or modulate the warp bubble so particles can’t remain in a stable area indefinitely. Lt. Cdr Data probably did that kind of thing all the time.
What interests me about the Alcubierre field (besides starships, etc.) is its possible applications. Imagine, for example, a static warp bubble generated at Earth’s surface with a radial “acceleration” of a=9.8 m/sec^2. Would this not create a finite space within which the acceleration of gravity would be negated?
I also wonder whether or not a changing warp field might not produce a “current” of gravito-electric energy in a manner similar to the electric current created by a changing magnetic field. If such a current culd be created and modulated, might it not be possible to generate a continuous “Hertzian” wave in spacetime — an FTL wave analogous to RF radiation? Keeping my ignorance of physics in mind, it seems to me that such a wave could be used as the basis of a form of FTL “radio” or “radar”.
It’s exciting news, no matter what.
I believe the “burst of radiation” problem can be easily remedied by pulsing the drive one and off, thus emitting the radiation episodically rather than in a single terminal (pun intended) burst.
For a while I puzzled over the kinetic energy particle impact problem with this idea, but decided it wasn’t an issue. I can’t back it up with math, but when the ship approaches a particle the particle will transitiion through the warp distortion and be accelerated along with the ship, probably retaining the same relative velocity that existed prior to the ship’s departure. If the particle misses the hull it will travel rearward, exit the field, and end up with its original velocity but at a greatly displaced location due to its short little hitchhike in the distortion field.
So my thought is that the kinetic energy equation doesn’t explode because despite the apparent velocity of the ship, it can’t actually make a high-velocity impact because potential impactors are swept up in the field along with the ship.
My question is; what actually happens at the distortion boundary? If spacetime is manipulated through the boundary in any significant way, stresses will be induced on any solid object due to changes in gravitational acceleration across the length of the object. Imagine a speck of dust entering the field. Suddenly, one end of the speck accelerates along the Z axis at 100g. The rest of the speck is twisted along the Y axis at 100g. Is this not going to be a problem for the speck?
In any case, I don’t know enough about physics to know all the ramifications of an artificial gravitational field. I look forward to reading more about this topic from you better-educated folks.
I’m not sure what the answer to that is, and it’s probably important because intersecting two such fields is the only way I can figure out how to target and destroy such a ship.
It can’t be attacked with beam weapons from behind because the light won’t catch up to the ship, and indeed won’t even exit the warp field of the pursuing vessel. It can’t be targeted from the front because it’s FTL and no information about its path or existence precedes its arrival. You can’t overhaul it from the side because you couldn’t detect it, or detect a course change, because light exiting the side of the field is likewise left far behind. (The light stays in a cone like a Mach 10 shock wave).
A ship can be pursued if the pursuer stays within the narrow light cone to the rear, and the target vessel can’t know its being pursued due to the aforementioned problem that no information about a ship precedes the ship’s warp field. But for the purser to destroy the target at warp, it would have to catch up or get a warp missile into the target’s own warp field so that beams, projectiles, or explosives could reach the hull, immediately raising the question about intersecting warp fields. I assume there’d be field cancellation, and that alone might be sufficient to tear the ship apart.
Given the narrowness of a warp 10 light cone, such encounters might prove rare, if not virtually impossible to execute, much like supersonic fighters that could only detect each other’s shock waves and exhaust trails, rendering interception a very happenstance affair.
And of course the other issue is that a sitting target would never see an attacker coming, while the attacker could exit warp (even emitting a huge burst), gather targeting information about the course and speed of the non-warp, non-maneuvering targets, jump back to warp (passing it’s own expanding light circle from when it was stationary, along with the emitted gamma rays from its earlier exit from warp), and appear within close proximity to its target, which would have had no way to be alerted. It’s all sneak attacks, and anyone not at warp is a sitting duck.
Perhaps it would be helpful to consider the analogous situations with sound and supersonic vehicles.
The sterilizing radiation is a feature, not a bug. It ensures that there won’t be any hostile alien lifeforms waiting for the colonists when they arrive.
No, it’s a bug. The Klingons discovered it first.
When your second ship arrives, however…
Well, as I mentioned, the paper seems to assume that the warp field won’t vary any over an interstellar trip, which I don’t think is a good assumption.
If you increase the field a little bit, the particles that had been in a stable position, riding right along with you, should draft back in the field, and if you decrease it a little bit they should drift forward. And of course slight course changes should send them out sides, keeping any major build-up from occuring. My thought is to let the boat rock a bit so the accumulated spray drains off the deck.
“My thought is to let the boat rock a bit so the accumulated spray drains off the deck.”
Scuppers
Note to Navigator: Per SOP, please ensure ship vector at de-warp is orthogonal to planetary surface. Wouldn’t want an unfortunate repeat of the “accident” at Pedobear’s Planet.
As always, wake me upon contact with Centauri Pilot – B Lewis, Commanding
Is it really necessary to use a warp drive to get to Alpha Centauri when time dilation means the trip doesn’t seem to take as long to someone in the ship as someone outside it?
Is it really necessary to use a warp drive to get to Alpha Centauri when time dilation means the trip doesn’t seem to take as long to someone in the ship as someone outside it?
It’s not necessary to go to Alpha Centauri at all. But if you are going and can go really fast for the cost, then there’s considerable value in doing it quicker.
Not at all. But getting up to the velocity required for significant dilation to kick in is a bear using pretty much anything from conventional physics.
Time dilation is only 0.5 at ≈0.866c, if I’m doing the math right. If you want it to be really significant, say 0.01, you have to be going 0.99995c.
George Turner, the more recent work requires an oscillating field. So you were again prescient in your solution to the problem, even if it’s intended to solve a different problem (the negative energy density required). Of course, that’s assuming that an oscillating field eliminates the problem of focused particle bursts.
On the other hand, the particle burst bug could be a feature if used over short distances. If the ship temporarily eliminated the oscillation, that is, it took it out of phase with the existing wave sequence, then you could create short bursts of focused particles with the same technique for weapon or long range communication purposes. We might even call it a name to indicate it was generated by taking the field out of the phase of its oscillations, something like… a “phaser.”
I’ll have to dig into the paper because there’s too much I don’t understand. Since the ship undergoes no intertial acceleration in its own reference frame, I assume its initial inertial velocity is unchanged by its trip at warp speeds (but affected by outside gravitational forces during its warp trip). That would make interplanetary missions radically different from the pure Newtonian trips we’re used to.
For example, if you went to Mars when it was in conjunction, you’d arrive with your old velocity vector from Earth’s orbit around the sun, way too much for orbiting Mars. To eat up the required delta-V you could drop out of warp ahead of Mars, at a low altitude, and let your velocity decay with what looks like a pure vertical flight from its surface. That’s still probably going to exceed Mars’ escape velocity, so you’d then have to warp back down and do it again, until you’ve burned off enough relative velocity for a low orbit, which you’ll enter by warping over to the noon side or midnight side of the planet.
So as a first approximation you’d take the planet’s fixed velocity vector, subtract your free vector after dropping out of warp (the error vector, to which you could add your desired orbital vector), treat that as a fixed vector aligned through the planet’s center, with the vector starting just above the atmosphere, and warp around to the base of that vector for the delta-V adjustment, and repeat as necessary.
The other new problem is that inertial navigation platforms would obviously be pretty useless because they’d never notice that you’re accelerating.
Selective destruction of the destination isn’t a bug, it’s a feature. Ask any Vogon, just don’t let him read any poetry.
Here’s a thought: if ETI has decided to leave us alone as long as we’re confined to our own system, the detection of a warp signature (even from White’s bench test warp interferometer) might persuade them to change their alien minds. Monkeys with nukes and rockets? Fine. Monkeys with planet-killing particle beam weapons and warp drives? OH HELL NO.
Keep watching the skies, folks
So we need to preemptively bomb the universe first to be “safe”, right?
@Stellvia, November 30, 2012, 2:17 pm:
Love the screenname.