The Anakro And The Time Projector

A time machine or a self-moving time traveller either remains stationary on the Earth's surface, thus "travelling" only through time, or passes from one set of spatiotemporal coordinates to another, thus "travelling" through both time and space or, as we have learned to say, through space-time. We need hardly list again the examples with which we have become familiar. There is at least one exception. In Poul Anderson's The Dancer From Atlantis, the anakro, a space-time vehicle, passes over the Earth's surface while time travelling.

Anderson covers every option. At present, we are rereading "Flight to Forever" in which a conventional time machine, the time projector, remains stationary not only on the Earth's surface but also at a fixed point in space during an entire cosmic cycle!

Onwards and upwards.