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 Valley Con contest. In addition, the convention even featured a life-size home made Stargate at its entrance. Sci-Fi Valley Con, Part 2 was held on May 17–19, 2013 in Altoona, Pennsylvania at the Jaffa Shrine Center. Over 2,000 visitors came out over the three days to support the event. An exact number cannot be given because it is reported that the promoter sold out of admission wristbands early Saturday evening of the convention and had to use left over wristbands from the previous year. <br> This was the first year for the conventions "indie sci-fi/horror film festival". Many films were submitted for