The warp drive: from science fiction towards science fact?
Not so long ago we had to assume that we’ll never be able to travel faster than light. This was based on scientists’ sensible belief that we can travel through space but cannot change the nature of space itself. Then the idea of ‘Warp Drive’ came along to challenge and seemingly change all of the barriers that Einstein’s theory identified. Warp Drive is all about squashing and stretching space — a pretty ambitious task to begin with. So maybe it’s time again to have a look at how far we’ve already come or how close we are to seeing a real warp drive built by humans.
In May 1994, theoretical physicist Miguel Alcubierre finally presented his proposal of “The Warp Drive: Hyper-fast travel within general relativity” in a scientific journal called Classical and Quantum Gravity.
He indeed was inspired by Star Trek and its creator Gene Roddenberry, who famously coined the expression “Warp Drive” to explain the inexplicable propulsion of the Starship Enterprise as prodigious speed was just necessary to enable his fictional space travelers to leap from star to star on their trek.
Up until 1994 there was just no in-depth scientific thesis (originating from the TV series or the mind of Roddenberry himself) about the concepts of warping space and time altogether. Thanks to the ‘Alcubierre Method’ of a Star Trek inspired Warp Drive it was inching its way closer to reality.
You don’t need to be Einstein to understand that his general theories of relativity puts a limit on the physical speed of objects within our universe. The only limit we know is the speed of light as any object approaching that speed becomes increasingly massive and heavy. It’d take exponentially more force to accelerate it any further. If any object could make it to the speed of light, it would become infinitely heavy — an impossibility.
So wouldn’t it be far more convenient to not move through space, but move space itself instead? It is — so the proposal asks, what if we could make the space in front of us, and everything in that space come to us? If that sounds too complicated or outright ridiculous to you, here is a good way to visualize this concept.
You probably the moving walkways at an airport. Now imagine you are standing still but the conveyor belt is moving. It is as though the region of the belt behind you is expanding while that region in front of you is contracting and thus disappearing as you move along and step off. It seems that Miguel Alcubierre found a theoretical way to simply turn space into a moving walkway.
Let us now get inside of a spacecraft with this kind of capability. Yes, our spacecraft would need to exist in a stable region of space unaffected by the warping of the space around it. This stable region is called flat space, and it would be surrounded by a bubble that distorted or warped the edges of that space in a special way. So behind this moving volume of stable space, new space is expanding and being created, while at the front, space is contracting and being annihilated. This process only needs to affect the space immediately behind and in front of the spacecraft in order to work.
What about G-Forces or even time-expansion for the occupants? Because the stable region of space is moving and not the travelers in relation to that space, they experience zip G-Forces, which comes in handy. Also, because they remain stationary within this flat space, there are no relativity effects such as time slowing down whatsoever. The time on their watches will still be the same one as at Mission Control. Amazingly, these effects, or better lack of effects, closely resemble those of the Star Trek TV series and movies.
It seems like a win-win situation for this new propulsion system, but the real question is how on earth or in space can we generate this warp field?
Usually, it is necessary to use matter to warp space. This warping is called a gravitational field. Therefore, for Alcubierre’s idea to become a reality it seemed that only a mini black hole would do. Even then it was not clear how the specific shape of this warp bubble could be produced. In his proposal Alcubierre determined that the region of warped space needed a negative energy density, and that some form of exotic matter could produce this. The problem was that the amount of exotic matter required would be the size of Jupiter.
In addition, there is the slight problem of the dust and other particles along the path of our starship. Remember that the warp field squeezes the space it meets out of existence, and that includes anything in that space. Atomic nuclei would experience massive compression forces and produce a plasma similar to the early stages of the Big Bang. A practical application of this fantastic theory seemed far away.
The wonderful thing about the human imagination lies in its refusal to surrender. A possible solution came from a very familiar source.
NASA’s Harold White turns to an excited audience and draws them into his world of interstellar travel. In a video on the Huffington Post U.K. YouTube channel he speaks of overcoming the problems linked with Warp Drive
Since 2010, his employment at NASA’s Johnson Space Center has included investigating Warp Drive propulsion. He looked at Alcubierre’s idea of a vessel surrounded by a ring that produces the negative energy density required. By playing with the warp equations he found that by changing the topology of the ring he could reduce the amount of exotic material needed to that equivalent to the voyager 1 spacecraft. All that was necessary was to make the thin ring thicker and more doughnut-shaped.
What Alcubierre’s exotic matter is, nobody knows. However, White is working with Q-Thrusters that utilize the Casimir effect; an effect that produces negative energy density.
To create this effect, two metal plates can be brought so closely together that there is not enough room left for the wavelength of virtual particles to fit inside. Virtual particles are predicted by Quantum Theory to pop in and out of existence continually in the vacuum of space. With these virtual particles only able to exist outside the plates, there is an imbalance that produces an external pressure on the plates. This force has been successfully measured since the 1990’s. White is looking at utilizing this negative energy density field for his Warp Drive.
According to cosmologists, our universe is already achieving faster-than-light travel by itself. They estimate the universe’s diameter to be about 92 billion light-years, yet it is only between 13 and 14 billion years old. This would suggest that the universe is expanding at its opposite extremities at seven times the speed of light. This demonstrates that the very fabric of space can expand at an enormous rate. Although at a local or galactic level, this effect is small because everything is moving together.
So, will we ever see a workable warp drive. Harold White believes that it is now at least plausible. The concept has moved steadily from science fiction towards science fact. Fittingly, the links between science fiction and science fact have proved remarkable in the continuing development of Warp Drive.