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 Of An Eye short film programme. Over its history Sci-Fi-London has also held a number of Short Film competitions, and in 2008 launched the Sci-Fi-London 48hr Film Challenge, in order to encourage filmmakers to create sci-fi short films over a very short period of time. In 2006, the festival became the official home of The Arthur C. Clarke Award, the most prestigious award for science fiction literature in Britain, and recognised as one of the most prestigious science fiction awards in the world. Since its inception, the Sci-Fi-London Film Festival has also been one of the few places in the