Anne-Marie Corley interviews Harold "Sonny" White:
The idea that nothing can exceed the speed of light limits our interstellar ambitions. How do we get round this?
Within general relativity, there are two loopholes that allow you to go somewhere very quickly, overcoming the restriction of the speed of light. One is a wormhole and the other is a space warp.
What is a space warp and how can it help?
A space warp works on the principle that you can expand and contract space at any speed. Take a terrestrial analogy. In airports we have moving walkways that help you cover distance quicker than you would otherwise. You are walking along at 3 miles an hour, and then you step onto the walkway. You are still walking at 3 miles an hour, but you are covering the distance much more quickly relative to somebody who isn't on the belt.
What would a starship with warp drive be like?
Imagine an American football, for simplicity, that has a toroidal ring around it attached with pylons. The football is where the crew and robotic systems would be, while the ring would contain exotic matter called negative vacuum energy, a consequence of quantum mechanics. The presence of this toroidal ring of negative vacuum energy is what's required from the math and physics to be able to use the warp trick.
What would it be like to travel at warp speed?
You would have an initial velocity as you set off, and then when you turn on the ring of negative vacuum energy it augments your velocity. Space would contract in front of the spacecraft and expand behind it, sending you sliding through warped space-time and covering the distance at a much quicker rate. It would be like watching a film in fast forward.
Even if travelling at warp speed is theoretically possible, don't the huge energy requirements make it unlikely?
When the idea was first proposed mathematically in 1994 it required a vast amount of negative vacuum energy which made the idea seem impossible. I did some work in 2011 and 2012 as part of the 100 Year Starship symposium and discovered ways to reduce the energy requirements by many orders of magnitude, so for a 10-metre diameter spacecraft with a velocity of 10 times light speed, I can reduce the negative energy needed.
How close are you to making this a reality?
We are very much in the science rather than the technology phase. We have got some very specific and controlled steps to take to create a proof of concept, to show we have properly understood and applied the math and physics. To that end we will try to generate a microscopic instance of a warp bubble in the lab and measure it.
If successful is the next stop Alpha Centauri?
We don't just go from the lab to an interstellar mission. There will be intermediate steps, other things we would do with this long before we get to some of the romantic pictures of a captain on the bridge telling the helmsman to engage warp drive.
Anne-Marie Corley, New Scientist