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Visitors From the Future Due This Year
Beware of homicidal grandchildren
Timothy James Neale (Two4Tea)
Published 2008-03-16 08:26 (KST)
Two Russian mathematicians have caused a stir in the normally staid world of theoretical physics.
Irina Aref'eva and Igor Volovich have not only proposed a mechanism for time travel, but they have given it a timetable as well. The pair, from the Steklov Mathematical Institute in Moscow, has been speculating on what might happen when the Large Hadron Collider (LHC) is switched on.
The European Organization for Nuclear Research (CERN) is expected to commission the LHC in May 2008. It will smash protons together at speeds previously unobtainable. Each proton will have the same kinetic energy as a flying mosquito, but that energy will be concentrated into one a trillionth of a mosquito's volume.
Collision like this can do very strange things to the fabric of the universe known as space-time. Space-time can bend and distort into loops that physicists call "closed time-like curves," known to sci-fi fans as "wormholes in space-time" or just "wormholes."
In the same way as two points on opposite ends of a piece of paper can be brought together by folding the paper in half, so a wormhole can provide shortcuts between distant points in space-time. It is these wormholes that Aref'eva and Volovich suggest may be produced by the LHC.
If, and it is a big "if," such wormholes are created, we are still a long way from building a time machine. Firstly, these mini-wormholes will only be big enough to allow sub-atomic particles through. Secondly, they will have the tendency to close up. Thirdly, we have no way to manipulate the mouths of the wormhole to act like a time machine.
But that does not mean that a future civilization will not have the technology to do these things from their end. Hence, if these wormholes are created by the LHC later this year, it could present our distance decedents the earliest opportunity to come and say hello.
A Bunch of Dingoes' Kidneys
But many physicists are unimpressed with the idea of time travel. It appears to break the law of causality. This law states that cause must precede effect.
There are paradoxes inherent in time travel. The classic example is the question of what would happen if you went back in time and murdered your grandfather before one of your parents was conceived, so preventing your own birth, so you did not travel back in time, so your grandfather lives …
Professor Stephen Hawking is a noted time travel skeptic. In 1992 he suggested that the laws of physics would conspire against time travel. His "chronology protection conjecture" says that creating wormholes that allow time travel will give rise to physical phenomena that act to block the wormholes.
Safe From Your Grandchildren, Probably
Aref'eva and Volovich's work is highly speculative. We simply do not know enough about the fine structure of space-time to predict with any certain what will happen when the LHC is switched on. But with experiments planned to look at some of the most fundamental questions in physics, the next few years will be very interesting at CERN, wormholes or not.