Three Laws of Robotics card-readers in "The Caves of Steel" have a capacity of only a few kilobytes per square centimeter of storage medium. "Aurora", in particular, presents a sequence of historical developments which explains the lack of nanotechnology — a partial retcon, in a sense, of Asimov's timeline. There are three Fourth Laws written by authors other than Asimov. The 1974 Lyuben Dilov novel, "Icarus's Way" (a.k.a., "The Trip of Icarus") introduced a Fourth Law of robotics: Dilov gives reasons for the fourth safeguard in this way: "The last Law has put an end to the expensive aberrations of designers to give psychorobots
Sci-Fi-London This normally takes the form of a shorter festival, held at venues including the Apollo Piccadilly Circus, the Stratford Picturehouse, the Royal Observatory, Greenwich and the Royal Society. The Arthur C. Clarke Award is awarded every year to the best science fiction novel which received its first British publication during the previous calendar year. The Award is chosen by Jury. The Award was set up in 1986 and the first winner was announced in 1987. In 2006, Sci-Fi-London hosted the Awards ceremony for the first time. As well as hosting the Arthur C. Clarke Award, Sci-Fi-London also chooses its own