Saturday, October 12, 2013

Faster-Than-Light Travel Post 2





The Alcubierre Warp Drive, theorized by Mexican physicist Miguel Alcubierre in 1994, is the most viable strategy of faster-than-light travel currently theorized. Both matter and information could theoretically be transported through the Warp Drive. It can also allow time-travel to the future through relativistic effects, but time-travel to the past is impossible. The Alcubierre Warp Drive  contracts space-time in front of spaceship and expands it behind the spaceship, creating a wave of space-time that the spaceship rides to travel faster than light speed. The spaceship using Alcubierre Warp Drive is kept in a warp bubble of flat space -- not moving, so no actual motion faster than light or other relativistic problems. The passengers of such a spaceship would not feel any acceleration, as they are technically at rest inside the bubble. It is the warped space-time around them that moves. The parallels with the Star Trek Warp Drive are obvious. Alcubierre bases his theory of warping space off the fact that space has no mass, allowing it be flexible and manipulated. Scientists have know the wavelengths of space have been expanding dramatically since the Big Bang.
However, the Alcubierre Warp Drive requires exotic matter or quantum techniques to create the space warp bubble and to violate normal energy requirements. Such exotic matter probably exists. Universal expansion has exceeded the speed of light in the past during the period of inflation in the big bang, and it will in the future, as the expansion of the universe is accelerating over time. The Casimir effect causes photons crossing space between uncharged conducting plates to move faster than the speed of light. Both of these processes imply the existence of some sort of exotic matter that allows faster-than-light travel. However, obtaining enough exotic matter and holding open a wormhole to allow true faster-than-light travel is considered impractical.
The original calculation ran into the problem that the energy required for the exotic matter that warps space-time would be roughly equal to the mass-equivalent of Jupiter. However, NASA physicist Harold White discovered that if he changed to shape of the warp bubble around the object from a flat halo to a more thick and curved form, the energy requirements would decrease to the mass-equivalent of Voyager 1, or about 1000 pounds. This could theoretically be reduced even further if the warped space-time was made to oscillate.
The Alcubierre Warp Drive has run into other problems, as well. Without violating normal energy requirements with exotic matter or the exploitation of  quantum effects, the Alcubierre Warp Drive, and all other known warp drives, would require an energy input of a mass-equivalent greater than that of the known universe. Also physicist Serguei Krasnikov, for exotic matter to create a warp bubble it would need to be traveling at faster-than-light speeds itself, which would be impossible. Also, the pilot of the spaceship would be unable to interact with anything outside the warp bubble, so the entire path of the ship would have to be arranged first, a process that would maybe require faster-than-light travel. This means that the creation of a functioning Alcubierre Warp Drive may require an Alcubierre Warp Drive. However, some physicists believe that there are ways to avoid these problems. Chris Van Den Broeck claimed in 1999 that he  had reduced the energy required to move smaller atoms to the mass-equivalent of a few milligrams. Anyway, NASA is currently working on developing such a Warp Drive, so it cannot be utterly out of the question.





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