Electronic Telegraph
6th April 1999

To the stars in a flash

There is fresh talk of space travel faster than the speed of light

Adrian Berry

WHAT hope for Star Trekkers? The space agency Nasa, unnoticed by the public, has conducted two seminars recently into the possibility of one day building spaceships that would travel faster than light.

The social consequences would be stupendous. A galactic empire could be built, as in Isaac Asimov's Foundation novels, in which people could hop from star to star within months, and the entire Milky Way was ruled by a single government.

At these Nasa meetings, physicists, mathematicians, engineers and hard-core science fiction writers examined that momentous 55-page document of 1916 that is proving to be one of the most complicated scientific papers ever written, Einstein's general theory of relativity.

The speakers and their audiences were well aware that they were venturing far beyond the boundaries of conventional science. Einstein's earlier work of relativity, the much simpler and better known special theory of 1905, rigorously rules out faster-than-light travel.

At that speed, its equations predict, a ship's mass would rise to infinity. One cannot therefore travel that fast and still remain part of this universe.

But the equations of the general theory make those of the earlier work seem almost provincial. They do not seem bothered about whether or not one remains part of this universe.

Ostensibly, the general theory does no more than predict the curving of space and time in the presence of a large mass, such as a star. But there is far more to it than that. In the 1916 equations, as the physicist Michio Kaku points out, there lurk all sorts of strange "goblins and demons", wormholes, time travel and other universes.

In particular, they predict the existence of "hyperspace", a region outside space-time in which there is no such thing as time or distance. All journeys through it are therefore instantaneous, and it would be possible, if the equations are really describing the actual cosmos (a matter of some debate), for a ship to vanish in one region of space and instantly reappear in another.

Asimov, in his novel The Stars Like Dust, wrote the classic fictionalised account of such a journey. Starship passengers are told:

"This is the captain speaking. We are ready for our first jump. We will be temporarily leaving the space-time fabric to enter the little-known realm of Hyperspace . . . There will only be minor discomfort.'

"It was like a bump which joggled the deep inside of a man's bones. In a fraction of a second the star view from the portholes had changed radically. The centre of the great Galaxy was closer now, and the stars appeared to thicken in number. The ship had moved a hundred light-years closer to them."

But Asimov had overlooked something. The "wormholes" that lead into hyperspace are too small for a ship to get through. Their width is only a billionth of a trillionth of a trillionth of a centimetre. Conference speakers were undeterred. A sufficiently advanced civilisation, said the cosmologist Kip Thorne, could widen a wormhole so that it could admit a spaceship. An electric field could be forced into it by means of a gigantic metal sphere. But that sphere would have to be an inconvenient 40 million miles wide.

There could be money in a special-relativity trip to the stars. People in a ship going at close to the speed of light would age very slowly. If they invested all their money at compound interest before they started, they would be very rich when they returned.

But alas there is only bad news for Star Trekkers. The highest speed of the Enterprise is Warp Nine, 1,516 times the speed of light, which would take it about 20 years to reach the centre of the galaxy. How useless!

Adrian Berry's new book, The Giant Leap: Mankind Heads for the Stars, is published today by Headline.