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note: because important websites are frequently "here today but gone tomorrow", the following was archived fromon May 7, 2009. This is NOT an attempt to divert readers from the aforementioned website. Indeed, the reader should only read this back-up copy if the updated original cannot be found at the original author's site.
Star Trek's "Warp Drive": Not Impossible
by Clara Moskowitz
Staff Writer / SPACE.com
The "warp drive" -- one of Star Trek's hallmark inventions -- could someday become Science instead of science-fiction.
Some physicists say the faster-than-light travel technology may one day enable humans to jet between stars for weekend getaways. Clearly it won't be an easy task. The science is complex. But not strictly impossible according to some researchers studying how to make it happen.
The trick seems to be to find some other means of propulsion besides rockets which would never be able to accelerate a ship to velocities faster than that of light (the fundamental speed limit set by Einstein's General Relativity).
Luckily for us, this speed limit only applies within space-time (i.e., the continuum of three dimensions of space plus one of time that we live in). While any given object can't travel faster than light speed within space-time, theory holds that perhaps space-time itself could travel.
"The idea is that you take a chunk of space-time and move it," said Marc Millis, former head of NASA's Breakthrough Propulsion Physics Project. "The vehicle inside that bubble thinks that it's not moving at all. It's the space-time that's moving."
Already happened?
One reason this idea seems credible is that scientists think it may already have happened. Some models suggest that space-time expanded at a rate faster than light speed during a period of rapid inflation shortly after the 'Big Bang'.
"If it could do it for the 'Big Bang', why not for our space drives?" Millis said.
To make the technique feasible, scientists will have to think of some creative new means of propulsion to move space-time rather than a spaceship.
According to General Relativity, any concentration of mass or energy warps space-time around it. (By this reasoning, Gravity is simply the curvature of space-time that causes smaller masses to fall inward toward larger masses.)
So perhaps some unique geometry of mass or exotic form of energy can manipulate a bubble of space-time so that it moves faster than light-speed and carries any objects within it along for the ride. [StealthSkater note: reminds me of the sci-fi "Dune" navigators whose "spice"-enhanced powers enabled them to do just that.]
"If we find some way to alter the properties of space-time in an imbalanced fashion so behind the spacecraft it's doing one thing and in front of it it's doing something else, will then space-time push on the craft and move it?" Millis said. This idea was first proposed in 1994 by physicist Miguel Alcubierre.
In the Lab
Already some studies have claimed to find possible signatures of moving space-time. For example, scientists rotated super-cold rings in a lab. They found that still gyroscopes placed above the rings seem to think they themselves are rotating simply because of the presence of the spinning rings beneath. The researchers postulated that the ultra-cold rings were somehow dragging space-time and the gyroscope was detecting the effect.
Other studies found that the region between 2 parallel uncharged metal plates seems to have less energy than the surrounding space. Scientists have termed this a kind of "negative energy" (which might be just the thing needed to move space-time).
The catch is that massive amounts of this negative energy would probably be required to warp space-time enough to transport a bubble faster than light speed. Huge breakthroughs will be needed not just in propulsion but in energy. Some experts think harnessing the mysterious force called "dark energy" -- thought to power the acceleration of the Universe's expansion -- could provide the key.
Even though it's a far cry between these preliminary lab results and actual warp drives, some physicists are optimistic.
"We still don't even know if those things are possible or impossible. But at least we've progressed far enough to where there are things that we can actually research to chip away at the unknowns," Millis told SPACE.com. "Even if they turn out to be impossible, by asking these questions we're likely to discover things that otherwise we might overlook."
Video: Star Trek's Warp Drive: Are We There Yet?
Video: Can We Time-Travel?
Top-10 Star Trek Technologies
Why Warp Drives Aren't Just Science Fiction
by Jillian Scharr, TechNewsDaily Staff Writer
June 25, 2013 / 11:59 AM ET
Astrophysicist Eric Davis is one of the leaders in the field of faster-than-light (FTL) space travel. But for Davis, humanity's potential to explore the vastness of space at warp speed is not science-fiction.
Davis' latest study "Faster-Than-Light Space Warps, Status and Next Steps" won the American Institute of Aeronautics and Astronautics' (AIAA) 2013 Best Paper Award for Nuclear and Future Flight Propulsion.
TechNewsDaily recently caught up with Davis to discuss his new paper which appeared in the March/April volume of the Journal of the British Interplanetary Society and will form the basis of his upcoming address at Icarus Interstellar's 2013 Starship Congress in August. [Super-Fast Space Travel Propulsion Ideas (Images)]
"The proof of principle for FTL space warp propulsion was published decades ago," said Davis referring to a 1994 paper by physicist Miguel Alcubierre. "All conventional advanced propulsion physics technologies are limited to speeds below the speed-of-light … Using an FTL space warp will drastically reduce the time and distances of interstellar flight."
Warp speed: a primer
Before delving into Davis' study, here's a quick review of faster-than-light space travel:
According to Einstein's theory of Special Relativity, an object with mass cannot go as fast or faster than the speed-of-light. However, some scientists believe that a loophole in this theory will someday allow humans to travel light-years in a matter of days.
In current FTL theories, it's not the ship that's moving — space itself moves. It's established that space is flexible. In fact, space has been steadily expanding since the 'Big Bang'.
By distorting the space around the ship instead of accelerating the ship itself, these theoretical warp drives would never break Einstein's special relativity rules. The ship itself is never going faster than light with respect to the space immediately around it.
Davis's paper examines the 2 principle theories for how to achieve faster-than-light travel: warp drives and wormholes.
The difference between the two is the way in which space is manipulated. With a warp drive, space in front of the vessel is contracted while space behind it is expanded, creating a sort of wave that brings the vessel to its destination.
With a wormhole, the ship (or perhaps an exterior mechanism) would create a tunnel through space-time with a targeted entrance and exit. The ship would enter the wormhole at sub-light speeds and reappear in a different location many light-years away.
In his paper, Davis describes a wormhole entrance as "a sphere that contained the mirror image of a whole other universe or remote region within our Universe, incredibly shrunken and distorted."
Sci-fi fans, for warp drives, think "Star Trek" and "Futurama." For wormholes, think "Stargate."
[See also: Warp Drive and Transporters: How 'Star Trek' Technology Works (infographic)]
Mirror, mirror on the hull
The next question is: how to create these space-time distortions that will allow vessels to travel faster than light? It's believed (and certain preliminary experiments seem to confirm) that producing targeted amounts of what's called "negative energy" would achieve the desired effect.
Negative energy has been produced in a lab via what's called the Casimir effect. This phenomenon revolves around the idea that vacuum -- contrary to its portrayal in Classical physics -- isn't "empty". According to Quantum Theory, vacuum is full of electromagnetic fluctuations. Distorting these fluctuations can create negative energy.
According to Davis, one of the most promising methods for creating negative energy is called the Ford-Svaiter mirror. This is a theoretical device that would focus all the quantum vacuum fluctuations onto the mirror's focal line.
"When those fluctuations are confined there, they have a negative energy," said Davis. "You could have types of negative energy that could make a wormhole that you could put a person through and if you make a bigger mirror put a starship through. The [mirror] is scalable … that's the beauty of it."
Davis described a theoretical configuration of Ford-Svaiter mirrors that could enable FTL spaceflight: "For a traversable wormhole, it'll have to be separate Ford-Svaiter mirrors [arranged] in an array to create the wormhole and then a ship with mirrors attached to it to extend the wormhole to the destination star."
The concern there is how to target the wormhole's exit.
"We don't know the answer to that question yet," said Davis. "Einstein's theory of General Relativity doesn't answer it."
That's the difference between the fields of physics and engineering, Davis explained. According to our current understanding of Physics, targeting the wormhole's exit is possible. But engineers have yet to figure out how to achieve it. [See also: NASA Turns to 3D Printing for Self-Building Spacecraft]
"On screen, Number One."
Another issue addressed in Davis' paper is how to navigate an FTL starship.
"If you're in a wormhole, you don't go faster than light. You're going at normal speeds. But your visualization and stellar navigations are all gone [because] … there are no stars to navigate by."
The iconic image of stars streaking by a spaceship viewscreen popularized by franchises like "Star Trek" and "Star Wars" simply isn't accurate, said Davis. "The light that goes through the wormhole gets distorted … You're going to have a very weird visual display."
This is because the negative energy necessary to create a wormhole or warp drive creates a repulsive gravity that distorts light around the ship.
So ships moving at faster-than-light speeds will not be able to observe their surroundings to calculate their location. Astronauts will have to rely on sophisticated computer programs to calculate their probable location. "You'll need something on the order of a supercomputer equipped with parallel processing," said Davis. "[The computer is] going to have to do all the figuring out … [using] input data from the last position and estimating."
This is more of a concern with warp drives (which are actively reshaping space as they travel) but not as much with traversable wormholes whose entrances and exits will probably be preset before flight. "You can only go one way through the wormhole, so it's not like you're going to get lost," said Davis
It's also important for the computer to be able to produce some kind of visual representation of its flight plan and spatial location. These images would then be rendered and displayed in the starship's cockpit or bridge for the crew to see and study. "It'll help the human psychological need for understanding in real time what the position changes of the stars are going to look like," said Davis.
Where no one has gone before
At the heart of Davis' paper is the principle (supported by rigorous scientific theory) that faster-than-light travel is a real and even tangible possibility. The last section of the paper proposes nine "next steps" that would push the field toward engineering prototypes and other practical tests of faster-than-light theories.
These steps include creating computer simulations to model the structure and effects of space warps. Davis also calls for more rigorous exploration of the Ford-Svaiter mirror which is still a largely theoretical device. The mirror is just one possible way to generate negative energy. Further study is needed to determine whether there are any other practical methods of achieving the same effect. [See also: Hypersonic 'SpaceLiner' Aims to Fly Passengers in 2050]
Davis describes the development and implementation of space-warp travel as "technically daunting" in his paper. But in conversation, he said he has no doubt that faster-than-light travel will someday be not only possible but necessary.
"The Earth is subjected to natural and outer space and ecological disasters so life is too fragile, while the planets in the Solar System are not very hospitable to human life. So we need to explore extrasolar planets for alternative homes," Davis said.
"This is all part of the growth and evolution of the human race."
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