There has been a lot of excitement over reports that NASA is developing a faster than light starship propelled by a warp drive capable of making journeys to nearby stars in mere weeks. There are even very pretty artist’s impressions of the hypothetical craft. Is a wonderful space operatic future among the stars lying just ahead of us?
Sadly no. There is though a grain of reality in the hyperbole. The man behind the story is engineer and physicist Harold G. White, who works at NASA’s Johnson Space Center. For the past few years White has promoted the concept of the warp drive (links to his scientific papers can be found at Crowlspace) .
Making information or matter travel faster than the speed of light appears to be utterly impossible. Faster than light speeds have never been observed (although there have been false alarms) and the hypothetical superluminal particles, tachyons, are still just that, hypothetical. In science fiction, most famously the Star Trek franchise, a propulsion system called warp drive enables starships to travel faster than light across the Milky Way. How is this meant to work? According to fiction, a warp drive bends space around the starship, enclosing it in a bubble of curved space. This bubble can move at speeds greater than light because Einstein’s speed limit does not apply to space itself. Meanwhile the ship is carried along inside the bubble. Does this science fiction fantasy have any relationship with reality?
Surprisingly, the answer is maybe. In 1994 a physicist called Miguel Alcubierre published a paper containing a sort of mathematical justification for warp drive. It described how the ship would draw itself forward by contracting spacetime ahead of it while expanding it behind in an effect analogous to one of those moving walkways they have at airports. However, for this to work, there must be a ring of intense negative energy wrapped around the ship. Negative energy is an impossible thing that does not exist, implying the existence of matter with negative mass (this is not the same thing as antimatter which can in theory be created although with extreme difficulty). Note too, this whole idea simply assumes that the whole “warp bubble” would indeed move faster than the speed of light. We simply do not know that.
Alcubierre’s warp drive concept is simply a theorist’s plaything, stretching Einsteinian physics to breaking point on paper to see what happens. Since then other researchers have suggested Alcubierre’s warp drive would in reality be immensely destructive, claiming EM radiation ahead of starship would be blue-shifted into lethal gamma rays. A real warp drive ship, theory suggests, would be an awesome doomsday device.
Harold White, leader of NASA’s Advanced Propulsion Team, claims to have improved upon Alcubierre’s concept, proving to his own satisfaction that it is feasible and open to experimental verification. White’s theories have not met with much acceptance from the wider community of physicists. Undaunted, White and colleagues have designed and built a bench-top setup to detect the distortions in space-time a warp field might generate should it exist. This test rig, a modified Michelson interferometer is a very small scale device. White and his collaborators have then applied thousands of volts to a small (about 5mm in diameter) ring of ceramic capacitors near the detector. White’s theory suggests the intense electric field created ought to generate a warp field which could be detected with the interferometer. To date the results obtained have been inconclusive, but White is hoping to refine his experiment, increasing its sensitivity.
This is a very small scale project, costing less than $50 000 to date. At conferences, Harold White talks up his research, perhaps giving some listeners the impression that this is a larger, better supported project than it is, with the clear goal of building a starship for human exploration of our stellar neighbourhood. In June 2014 White published the beautiful photorealistic images of a hypothetical starship that have caught the public’s imagination. White commissioned these illustrations from artist Mark Rademaker, the design is closely based on White’s specifications (with rather a lot of Star Trek inspiration too, it is even named Enterprise) but I am unclear how ‘official’ the artwork is. Like all good sci-fi ships the design is unnecessarily streamlined and seems to magically simulate gravity inside its hull so that the interior is laid out like that of a boat. I used to spend hours as a kid carefully drawing starships, this concept is much prettier than my sketches but sadly no more realistic. It is hard to believe this delightful collection of fanciful art was funded by NASA. Allegedly White has said a vessel based on his theories could travel from Earth to Alpha Centauri, 4.3 light years away, in two weeks but this seems a mere assertion, being unproven and in fact as of now unprovable.
I am sorry to throw cold water on a story that has excited so many around the world. but in short, faster than light travel is still as impossible as it has ever been. NASA has not discovered how to travel faster than light, is not constructing a prototype warp drive and definitely not currently even planning a spacecraft based on White’s research. Rather NASA is very modestly funding a small scale research project to explore one researcher’s speculations about physics which if correct offer a slight chance than it may be possible to manipulate space-time. The researcher in question is (perhaps prematurely) passionately promoting his work.
This research by White and colleagues could (and most likely will) lead nowhere, turning out to be another scientific self-delusion like cold fusion or polywater. Yet it is still worth looking at because it is not costing much and the payoff could be huge: anything that could easily take humanity to the stars would be an awesome step in our species’ history. Just don’t count your starships before they’re launched.
(UPDATE: Harold White has investigated other unconventional propulsion concepts. He is a member of a team which in July 2014 claimed to have verified a reactionless thruster device, a concept which violates the very well-established law of conservation of momentum. More recently the Eagleworks team claim to have observed space-warping effects inside one of their reactionless thruster test devices.)
(article by Colin Johnston, Science Education Director, last updated 13 May 2015)