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 on the Rock Rock has had a number of guests of different types. Below is a list of guests they have had at their festival. The Sci-Fi on the Rock committee spends the rest of the time they are not planning the convention going to outside events. Often these events invite the public to join them in doing different things. Some events that Sci-Fi on the Rock has hosted or attended in the past include: Merry Geek-mas is a craft fair hosted by Sci-Fi on the Rock around the end of November or beginning of December each year. Sci-Fi on the Rock vendors