New theory for time travelling wormholes
Thursday, 13 April  2000

	The Pulkovo Observatory in St Petersburg where Sergei Krasnikov calculated the possibility of large wormholes (Photo by O.P.Bykov).

If you thought travelling in wormholes was the stuff of science fiction, you may have to think again. Intergalactic space travel is back on the agenda according to this week's New Scientist.

A Russian expert in relativity, Sergei Krasnikov of the Pulkovo Observatory in St Petersburgh has done some new calculations based on Einstein's general theory of relativity to support the existence of cosmic shortcuts which allow travel, at faster than the speed of light, to another galaxy and another time.

According to New Scientist, other theorists admit to being intrigued by the new work, but remain cautious.

"It's worth taking seriously," says Ian Moss, a relativity expert at the University of Newcastle upon Tyne. "The main worry is that it could fall down on some technical detail."

Paul Davies of Imperial College, London, adds that proving something is theoretically possible does not prove it actually exists: "My feeling is that the matter is still open," he says.

It is currently speculated that tiny quantum wormholes - at the level of quarks and electrons - may exist for short periods of time. But most experts suspect that some fundamental law of physics prevents the formation of large wormholes.

Quite apart from the fact that they could allow time travellers to go back in time and prevent their own birth by accidently killing one of their parents, wormholes that were large enough for humans to travel through would need to be crammed with 'exotic matter' to keep them open.

But Krasnikov has found a new type of wormhole that is compatible with the known laws of physics, yet can be as big and stable as you like.

His wormholes create their own exotic matter out of nothing when space and time are curved in the right way, in sufficient quantities to make it big enough and keep it open long enough for people to use.

"What's new is that this wormhole actually generates enough to make it arbitrarily large," says Krasnikov who works at the Laboratory of Stellar Physics.

"From a mathematical point of view, it's an interesting exercise," says astrophysicist Simon Johnston of Sydney University. "The tricky bit is verifying it - you'd need to sample the exotic matter for a start."

Krasnikov accepts that testing his claims by building a wormhole is far beyond present technology.