Passport to the Universe

Sci-fi Star Trek Vulcan starship with warp drive. Image Source: CBS / Star Trek via i09.

Next Stop: Alpha Centauri. In November 2012, i09 reported on a new research breakthrough from physicist Harold White that resolves our inability to travel faster than the speed of light. It builds on a finding from the mid-1990s and works around a problem discovered with warp drives at that time. It has NASA very interested. This method could see us travel to nearby star systems in a matter of weeks, making science fiction start travel a reality. I09 reports:

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 — and all without violating Einstein's law of relativity. We contacted White at NASA and asked him to explain how this real life warp drive could actually work. ...

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.

Michio Kaku dubbed Alcubierre's notion a "passport to the universe." It takes advantage of a quirk in the cosmological code that allows for the expansion and contraction of space-time, and could allow for hyper-fast travel between interstellar destinations. Essentially, the empty space behind a starship would be made to expand rapidly, pushing the craft in a forward direction — passengers would perceive it as movement despite the complete lack of acceleration.

White speculates that such a drive could result in "speeds" that could take a spacecraft to Alpha Centauri in a mere two weeks — even though the system is 4.3 light-years away.

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."

And indeed, early assessments published in the ensuing scientific literature suggested horrific amounts of energy — basically equal to the mass-energy of the planet Jupiter (what is 1.9 × 10²⁷ kilograms or 317 Earth masses). As a result, the idea was brushed aside as being far too impractical. Even though nature allowed for a warp drive, it looked like we would never be able to build one ourselves.

"However," said White, "based on the analysis I did the last 18 months, there may be hope." The key, says White, may be in altering the geometry of the warp drive itself.

... "My early results suggested I had discovered something that was in the math all along," he recalled. "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.

He presented the results of his Alcubierre Drive rethink a year later at the 100 Year Starship conference in Atlanta where he highlighted his new optimization approaches — a new design that could significantly reduce the amount of exotic matter required. And in fact, White says that the warp drive could be powered by a mass that's even less than that of the Voyager 1 spacecraft.

That's a significant change in calculations to say the least. The reduction in mass from a Jupiter-sized planet to an object that weighs a mere 1,600 pounds has completely reset White's sense of plausibility — and NASA's.

Other reports: here, here, here, here and here.