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 Sci-Fi-London SCI-FI-LONDON (The London International Festival of Science Fiction and Fantastic Film, SFL), is a United Kingdom-based film festival, dedicated to the science fiction and fantasy genres, which began in 2002. Designed to be a festival that “takes a serious look at sci-fi and fantasy, bringing new, classic and rare movies from around the world to the UK”, Sci-Fi-London annually screens world and UK Premieres, seminal cult classics, as well as documentaries, debates and talks. Short films are also an important part of the festival programme, screening in front of every movie shown, as well as together in the Blink