You know that scene in the film Contact where the “Machine” is spooling up, its three spinning rings kicking out crazy light and an electromagnetic field powerful enough to pitch nearby Navy battleships sideways, as Ellie (Jodie Foster) waits, terrified, in her tiny spherical craft above the space-time bedlam, to plummet into the vortex?
Yeah, that’s not exactly how NASA’s envisioning faster-than-light space travel, but…wait, NASA’s working on faster-than-light travel? Isn’t that impossible?
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Of course it is. Nothing can travel faster than light, right? To do so would violate the special theory of relativity, which stipulates that you’d need an infinite amount of energy to accelerate a particle with mass to light speed. We’ve all heard this pretty much since we were kids. Has someone finally proven special relativity wrong?
Not at all, but with respect to travel between the stars, someone did come up with a radical-sounding hypothetical workaround 18 years ago.
In a paper titled “The Warp Drive: Hyper-fast travel within general relativity” published in science journal Classical and Quantum Gravity in May 1994, physicist Miguel Alcubierre suggested a mechanism for getting an object from one point to another at faster-than-light speeds without running afoul of Einsteinian relativity.
Alcubierre’s idea: bending space-time in front of and behind a vessel rather than attempting to propel the vessel itself at light-speeds.
According to Alcubierre, in the paper abstract …
… [it] is shown how, within the framework of general relativity and without the introduction of wormholes, it is possible to modify a spacetime in a way that allows a spaceship to travel with an arbitrarily large speed. By a purely local expansion of spacetime behind the spaceship and an opposite contraction in front of it, motion faster than the speed of light as seen by observers outside the disturbed region is possible. The resulting distortion is reminiscent of the ‘warp drive’ of science fiction.
Harold White
By placing a spheroid object between two regions of space-time — one expanding, the other contracting — Alcubierre theorized you could create a “warp bubble” that moves space-time around the object, effectively re-positioning it. In essence, you’d have the end result of faster-than-light travel without the object itself having to move (with respect to its local frame of reference) at light-speed or faster.
The only catch: Alcubierre says that, “just as happens with wormholes,” you’d need “exotic matter” (matter with “strange properties”) to distort space-time. And the amount of energy necessary to power that would be on par with — wait for it — the mass-energy of the planet Jupiter.
So we’re back to “fuhgeddaboudit,” right?
Maybe not. According to NASA physicist Harold White, the energy problem may actually be surmountable by simply tweaking the warp drive’s geometry.
White, who just shared his latest ideas at the 100 Year Starship 2012 Public Symposium, says that if you adjust the shape of the ring surrounding the object, from something that looks like a flat halo into something thicker and curvier, you could power Alcubierre’s warp drive with a mass roughly the size of NASA’s Voyager 1 probe.
In other words: reduction in energy requirements from a planet with a mass equivalent to over 300 Earths, down to an object that weighs just under 1,600 pounds.
What’s more, if you oscillate the space warp, White claims you could reduce the energy load even further.
“The findings I presented today change [Alcubierre's warp drive] from impractical to plausible and worth further investigation,” White told SPACE.com. “The additional energy reduction realized by oscillating the bubble intensity is an interesting conjecture that we will enjoy looking at in the lab.”
That’s right, an actual lab experiment, whereby White says he plans to simulate the tweaked Alcubierre drive in miniature, using lasers “to perturb space-time by one part in 10 million.”
And if it works? Don’t expect to go Alpha Centauri-hopping any time soon, but the idea well down the road, according to a presentation delivered by White on the subject last year, would involve a spacecraft leaving Earth, traveling a given distance using conventional propulsion, stopping (relative to the Earth), enabling its “warp field,” then traveling to a point near its interstellar destination, where it would then disable the field and continue on its way using conventional propulsion methods once more.
Star Trek meets Contact, in other words.
Instead of taking “decades or centuries,” White says this would allow us to visit a spot like Alpha Centauri — a little over four light years from us — in as little as “weeks or months.”
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