George Dvorsky, io9 (November 26, 2012)
"A few months ago, physicist Harold White stunned the aeronautics world when he announced that he and his team at NASA had begun work on the development of a faster-than-light warp drive. His proposed design, an ingenious re-imagining of an Alcubierre Drive, may eventually result in an engine that can transport a spacecraft to the nearest star in a matter of weeks...."
This isn't as crazy as it may sound. The original Alcubierre equations were taken seriously by physicists: as a fascinating and impractical theory. An Alcubierre warp drive, as originally presented, would have used incredible amounts of power: and might not be stable. (June 12, 2009)
Tweaking the Numbers
"...The idea came to White while he was considering a rather remarkable equation formulated by physicist Miguel Alcubierre. In his 1994 paper titled, 'The Warp Drive: Hyper-Fast Travel Within General Relativity,' Alcubierre suggested a mechanism by which space-time could be 'warped' both in front of and behind a spacecraft...."...In terms of the engine's mechanics, a spheroid object would be placed between two regions of space-time (one expanding and one contracting). A 'warp bubble' would then be generated that moves space-time around the object, effectively repositioning it — the end result being faster-than-light travel without the spheroid (or spacecraft) having to move with respect to its local frame of reference.
" 'Remember, nothing locally exceeds the speed of light, but space can expand and contract at any speed,' White told io9. 'However, space-time is really stiff, so to create the expansion and contraction effect in a useful manner in order for us to reach interstellar destinations in reasonable time periods would require a lot of energy.'..."
For early version of the Alcubierre warp drive, "a lot of energy" meant at least what you'd get by converting Jupiter - 317 times as massive as Earth - into energy.
That sort of energy requirement made Alcubierre's equations interesting, but impractical.
Equations, Assumptions, and 'Impossible'
What is or isn't possible depends partly on assumptions. A 'warp drive' is impossible, for instance, assuming that:- Technology will never improve
- Alcubierre's paper covered all possibilities
That's when Konstantin Tsiolkovsky published "The Exploration of Cosmic Space by Means of Reaction Devices."
A hundred years later, some folks were wondering when people would go back to the Moon.
Tweaking the Numbers
Harold White explained how looking at Alcubierre's work a little differently made a big difference:"...'I suddenly realized that if you made the thickness of the negative vacuum energy ring larger - like shifting from a belt shape to a donut shape - and oscillate the warp bubble, you can greatly reduce the energy required - perhaps making the idea plausible.' White had adjusted the shape of Alcubierre's ring which surrounded the spheroid from something that was a flat halo to something that was thicker and curvier...."
(io9)
'Are We There Yet?'
"...White and his colleagues are trying to simulate the tweaked Alcubierre drive in miniature by using lasers to perturb space-time by one part in 10 million...."...'Our initial test device is implementing a ring of large potential energy - what we observe as blue shifted relative to the lab frame - by utilizing a ring of ceramic capacitors that are charged to tens of thousands of volts,' he told us. 'We will increase the fidelity of our test devices and continue to enhance the sensitivity of the warp field interferometer - eventually using devices to directly generate negative vacuum energy.'
"He points out that Casimir cavities, physical forces that arise from a quantized field, may represent a viable approach...."
(io9)
Bending space-time by one part in 10 million won't take us to other stars. But if that ring of capacitors bends space-time even a little, that will show that the theory works.
Change Happens
Space ships with warp engines won't be built in the next year or so: in the Lemming's opinion. For starters, negative vacuum energy rings aren't off the shelf hardware. Today.But let's remember that change happens. Leonardo Da Vinci drew pictures of flying machines. About five centuries later, internal combustion engines made powered fight possible.
Maybe folks will know how to build negative vacuum energy rings five centuries from now.
On the other hand, White wants to pump tens of thousands of volts of energy into a ring of ceramic capacitors: to see whether and how much space-time gets stretched.
Warp drive could be closer than it seems.
A tip of the Lemming's hat to Thomas Sanjurjo, on Google+, for the heads-up on this article.
Related posts:
- "Antimatter Rocket Motor: Physics, Straightforward; Engineering, Not So Much"
(October 26, 2012) - "Time, the Universe, and Space Aliens"
(April 20, 2012)
Particularly - "Faster Than the Speed of Light: Maybe"
(November 25, 2011) - "Interstellar Space Probe: Thirty Years Later"
(May 9, 2010) - "Warp Speed Kills? Let's Say It's an Engineering Challenge"
(March 11, 2010)
