Alderson Drive - Overview

Overview

The Alderson drive is not, strictly, a faster-than-light drive: it can more nearly be likened to a device able to use a form of wormhole, whose entry and exit 'Alderson points' are at either end of an 'Alderson tramline'. Alderson points are difficult to find. Alderson tramlines form between points of equipotential thermonuclear flux located near stars. Not all star pairs form Alderson tramlines, and not all those tramlines which do form are large enough to take a spaceship. This means that in order to travel between star systems, it is frequently necessary to carry out a series of Alderson jumps interspersed with periods of travel between Alderson points in normal space. Alderson tramlines, when they form, form instantaneously, and travel along them appears to take no elapsed time. However, sentient beings who travel using an Alderson drive experience "jump shock", a temporary period of extreme disorientation immediately following an Alderson jump. Computers are affected for an even longer period of time, making it difficult to automate spacecraft after a jump. Spacecraft are thus vulnerable to attack until their occupants recover from jump shock.

At the beginning of The Mote in God's Eye, only one tramline leads to Mote system. Its inner end is well above the plane of the local ecliptic and its outer end appears inside the photosphere of a red giant star. The Mote civilizations had long been able to construct an Alderson-type drive but, because they had no Langston Field technology, their many attempts to use the drive always failed: their unshielded ships making a jump were burnt up by the red giant's photosphere. Then the battlecruiser INSS MacArthur arrived in their system, leading to the events in the novel and its sequel.