The SciencesComputer Recreations, December 1985The search for an invisible ruler that will help radio astronomers to measure the earthBy A. K. Dewdney on December 1, 1985AdvertisementABOUT THE AUTHOR(S)Recent Articles by A. K. DewdneyDIY Fractals: Exploring the Mandelbrot Set on a Personal ComputerPhotovoresTuring Test