spindizzy

An engine-powered miniature racing car running on a circular track, tethered by cables to a central pole, popular in the 1940s.

Spindizzies, or tether cars, come in three categories of descending value: original as raced, restored and reproduced. […] The best indicator of a spindizzy’s authenticity is its size, said Eric Zausner of Berkeley, Calif., who has an extensive collection. “Repros are always smaller because they come from second-generation molds.”

An engine-powered miniature racing car running on a circular track, tethered by cables to a central pole, popular in the 1940s.

Spindizzies, model auto racing fans to you, are going to have a field day at Safford Junio[r] High School grounds, facing South Fourth avenue, this afternoon.

An anti-gravity propulsion system capable of faster-than-light travel, powered by the hypothetical Blackett effect.

So the twin scientific themes of the first book are the development of antigravity technology called spindizzies that enable whole cities to lift into space, and the production of "anti-agathic" drugs that can extend life indefinitely, necessary for the immense journey times in interstellar space.