Ride the celestial subway (original) (raw)

WHAT is the most efficient route from the Earth to the moon or the planets? According to NASA engineers, the answer is simple. Travel the way Londoners do: go by tube.

The idea is not entirely original. Peter Hamilton’s recent science-fiction novel Pandora’s Star portrays a future in which people travel by train to planets encircling distant stars. True, the railway lines have to pass through a wormhole – a short cut through space-time – but once you can build wormholes to order, it’s entirely logical to use trains. Much earlier, E. E. “Doc” Smith came up with the hyperspatial tube, used by malevolent aliens to invade human worlds from another dimension. And C. C. MacApp imagined a universe in which star systems were connected by a system of tubes, through which spaceships could travel faster than light.

Although we don’t yet have wormholes, extra dimensions, or faster-than-light tunnels through space, mathematicians have discovered that our solar system does possess something remarkably similar to the wild inventions of these authors’ imaginations: a network of tubes perfectly suited to space travel. The tubes can be seen only through mathematical eyes, because their walls are defined by the combined gravitational fields of all the bodies in the solar system, but they are real enough, for all that. If we could visualise the ever-changing fields that control how the planets, moons, asteroids and comets move, we would be able to see a network of tubes that swirl and twirl along with the planets as they perform their endless gravitational dance. NASA’s engineers already refer to the network as the “Interplanetary Superhighway”: science fiction wins again.…