viernes, 12 de junio de 2009
Warp Drive Engine
Could Suck Earth Into Black Hole?
Star Trek makes faster-than-light travel look easy, but new calculations show a warp drive could easily create a black hole that would incinerate any passengers on a space craft and then suck Earth into a black hole.
Star Trek" makes faster-than-light travel look easy, but according to new calculations by Italian physicists, a warp drive could easily create a black hole that would incinerate any passengers on a space craft and then suck Earth into a black hole.
"Warp drives are so far the best case scenario to attain faster-than-light travel," said Stefano Finazzi of Italy's International School for Advanced Studies. This paper "makes it much harder to realize, if not almost impossible, warp drives."
In normal physics, nothing can move faster than the speed of light. Einstein's theory of relativity forbids it. In normal space any object approaching the speed of light will increase in mass exponentially, and require an exponential increase in the amount of power needed to propel it forward.
There are two exceptions to this rule however. The first is what's commonly called a worm hole, a bridge connecting two different parts of space. A ship crossing this bridge would move at below light speed, but still arrive before a beam of light that would have had to go the long way around.Warp drives are the second and more appealing option. A ship can't move through space faster than the speed of light. But with enough energy, space itself can move faster than the speed of light.
Known for the Mexican physicist Michael Alcubierre who originally developed the idea in the 1990's, an Alcubierre warp drive would create a bubble of energy behind the ship and a lack of energy in front of the ship, like a giant cosmic wave a space ship could surf. That particular section of space can travel faster than the speed of light in the surrounding space, and anything on or in that bubble will accelerate with it.
Finazzi and his colleagues propose creating this bubble of space-time by using a massive amount of "exotic matter," or dark energy. (Exactly how this bubble would be created is still a mystery.) According to their calculations and simplified, it would take a huge amount of energy to create the bubble, and then increasing amounts of energy to contain the highly repulsive dark energy.
Eventually the energy would run out. The bubble would rupture, with catastrophic effects. Inside the bubble the temperature would rise to about 10^32 degrees Kelvin, destroying almost anything on the bubble.
Anyone watching the ship nearby wouldn't be much better off.
"We know that the warp drive will be destabilized," said Finazzi. "But we do not know if it will in the end explode or collapse to a black hole."Other physicists agree with the Italians' calculations, up to a point.
"It's a good paper; their results are sound," said Gerald Cleaver, a professor of physics at Baylor University who reviewed the work. The results make sense, at least, when creating warp drive using exotic matter in a universe where 1 plus 1 equals 2.
In a universe where 1 plus 1 equals 3, a possibility with string theory instead of the semi classical physics used by the Italians, a stable warp drive is viable.
Last year Cleaver and co-author Richard Obousy detailed a string theory-based warp drive that creates a bubble of space time by expanding one of the tiny, rolled-up dimensions (instead of a bubble of dark energy) predicted by string theory.
The biggest sticking point to a extra dimension-based warp drive? The entire mass of Jupiter would have to be converted into pure energy to power it.
The real question is not whether a warp drive, which by Cleaver's estimate is hundreds of years away, will be stable or not. It's about the fundamentals of the universe; do we live in a universe where 1 plus 1 equals 2 or 3? Until scientists can answer that question, there will be significant limitations on scientific models of the universe.
"These papers suggest limitations to what we can and can't do," said Cleaver. "We as scientists enjoy these papers because then we can look for ways to get around those limitations."