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 also features information on past festivals, how to volunteer at the festival, as well as a "Mailing List" and "Message Board/Forum". SCI-FI-LONDON.COM also operates a free 'webTV' service at SCI-FI-LONDON.TV, featuring films and shorts previously submitted or screened at past festivals. 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