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 (G.I. Joe) as immobile as a rock, with no discernible movement of any kind. At a range of 2 1/2 miles, the impact spot of laser light will jump one hundred feet for every one thousandth of an inch movement at the source. Sci-Fi transcends mere stillness to hold that spot on target, long enough to burn through that source. Sci-Fi took a leave of absence to complete his master's degree in electrical engineering, returning with the skill set necessary to enact unparalleled enhancements to the security systems in G.I. Joe headquarters. As part of the Star Brigade aeronautical group, Sci-Fi was