The Dillon-Wagoner Graviton Polarity Generator, known colloquially as the spindizzy, is a fictitious anti-gravity device imagined by James Blish for his series Cities in Flight. This device grows more efficient with the amount of mass being lifted, which was used as the hook for the stories—it was more effective to lift an entire city than it was to lift something smaller, such as a classic spaceship. This is taken to extremes in the final stories, where an entire planet is used to cross the galaxy in a matter of hours using the spindizzy drive.