Star Trek voyages edge closer to reality
Scientific advances mean that warp speed - travelling faster than light - could enable spacecraft to reach stars in months or weeks
Beyond the security gate at the Johnson Space Centre's 1960s-era campus in Houston, Texas, inside a two-storey glass and concrete building, there is a floating laboratory.
Harold White, a physicist and advanced propulsion engineer at Nasa, beckoned towards a table full of equipment there on a recent afternoon: a laser, a camera, some small mirrors, a ring made of ceramic capacitors and a few other objects.
He and other Nasa engineers have been designing and redesigning these instruments, with the goal of using them to slightly warp the trajectory of a photon, changing the distance it travels in a certain area, and then observing the change with a device called an interferometer.
So sensitive is their measuring equipment that it was picking up myriad earthly vibrations, including people walking nearby. So they recently moved into this lab, which floats atop a system of underground pneumatic piers, freeing it from seismic disturbances.
The team is trying to determine whether faster-than-light travel - warp drive - might someday be possible.
Warp drive. Like on Star Trek.
"Space has been expanding since the Big Bang 13.7 billion years ago," said White, 43, who runs the research project. "And we know that when you look at some of the cosmology models, there were early periods of the universe where there was explosive inflation, where two points would've went receding away from each other at very rapid speeds.
"Nature can do it," he said. "So the question is, can we do it?"
Einstein famously postulated that, as White put it, "thou shalt not exceed the speed of light," essentially setting a galactic speed limit. But in 1994, a Mexican physicist, Miguel Alcubierre, theorised that faster-than-light speeds were possible in a way that did not contradict Einstein, though Alcubierre did not suggest anyone could actually construct the engine that could accomplish that.
His theory involved harnessing the expansion and contraction of space itself. Under Alcubierre's hypothesis, a ship still could not exceed light speed in a local region of space. But a theoretical propulsion system he sketched out manipulated space-time by generating a so-called "warp bubble" that would expand space on one side of a spacecraft and contract it on another.
"In this way, the spaceship will be pushed away from the Earth and pulled towards a distant star by space-time itself," Alcubierre wrote.
But Alcubierre's paper was purely theoretical, and suggested insurmountable hurdles.
White believes that advances he and others have made render warp speed less implausible. Among other things, he has redesigned the theoretical warp-travelling spacecraft in a way that he believes will greatly reduce the energy requirements.
Steve Stich, the deputy director of engineering at the Johnson Space Centre, said: "You always have to be looking towards the future." He held up his iPhone.
"Forty years ago, this was Star Trek, Captain Kirk talking on a communicator whenever he wanted to," he said. "But today it exists because people made the battery technology that allows this device to exist, worked on the software technology, worked on the computational technology, the touch screen."
Theoretically, a warp drive could cut the travel time between stars from tens of thousands of years to weeks or months. But we should probably not book reservations anytime soon.