A spindizzy is a device described by James Blish in his Cities in Flight series of science fiction books.
The spindizzy was invented after huge research carried out on Jupiter, which involved building a truly massive bridge made out of ice. The resulting insights into the link between electron spin and gravity allowed this device to be constructed, and on the first flight from Earth to near Jupiter, the device ran on a couple of AA cells(!)
The name was coined because of the effect that an electron experiences whilst within the field.
The spindizzy field gives an antigravity effect with weak FTL effects that can be used on large objects, such as huge ships, whole cities, or even, with some difficulty, whole planets, and permits travel through space thousands or millions of lightyears. The field keeps in the atmosphere as well as letting light in and protecting from radiation.
However the minor disadvantage it has is that it still takes hundreds of years to get places, but that's ok because anti-agathics have been invented that means you don't have to get old. Handy that.