To date the fastest speed ever traveled by humans is just under 25,000 miles per hour. This milestone was reached by the reentry capsule from the Apollo 10 moon mission — reaching 24,961 mph as it hurtled through Earth’s upper atmosphere. Yet this pales in comparison to the speed of light, which clocks in at 186,282 miles per second, in a vacuum. A quick visit to the calculator puts Apollo 10 at 6.93 miles per second, or 0.0037 percent speed of light!
Despite our very pedestrian speeds many dream of a future where humans might reach the stars, powered by some kind of “warp drive” (yes, Star Trek comes to mind). A handful of researchers at NASA are actively pondering this today. Though, our poor level of technology combined with our lack of understanding of the workings of the universe, suggests that an Alcubierre-like approach is still centuries away from our grasp.
From the New York Times:
Beyond the security gate at the Johnson Space Center’s 1960s-era campus here, inside a two-story glass and concrete building with winding corridors, there is a floating laboratory.
Harold G. White, a physicist and advanced propulsion engineer at NASA, beckoned toward 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 Dr. 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 Dr. 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, theorized that faster-than-light speeds were possible in a way that did not contradict Einstein, though Dr. 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 Dr. Alcubierre’s hypothesis, a ship still couldn’t 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,” Dr. Alcubierre wrote. Dr. White has likened it to stepping onto a moving walkway at an airport.
But Dr. Alcubierre’s paper was purely theoretical, and suggested insurmountable hurdles. Among other things, it depended on large amounts of a little understood or observed type of “exotic matter” that violates typical physical laws.
Dr. White believes that advances he and others have made render warp speed less implausible. Among other things, he has redesigned the theoretical warp-traveling spacecraft — and in particular a ring around it that is key to its propulsion system — in a way that he believes will greatly reduce the energy requirements.
Read the entire article here.