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 Lullabies albums." Writing for "Vox", Simon Price felt that Anderson wrote some of his funniest lyrics on CD2, on the tracks "Young Men" and "Jumble Sale Mums". Aside from "Duchess", which he called "lazy rubbish," he had strong praise for both discs. The album continued Suede's run of consecutive top ten albums, peaking at no. 9 in October 1997. Despite never placing on any of "Billboard"'s charts, "Sci-Fi Lullabies" had sold 19,000 units in the US by 2008, according to Nielsen SoundScan. Keith Phipps of "The A.V. Club" and Scott Plagenhoef of "Stylus Magazine" spoke of the effort invested in Suede's