A fabric which normally is flexible, like cloth, but under a blow becomes rigid all over. It provides protection against injury from such things as bullets, blows, and falls. Impact armor does not appear to be in common use in Human space. In 2657 a Puppeteer spacesuit incorporated impact armor.
Reference: "The Soft Weapon", The Ringworld Engineers
By 2490, the common language of Human Space, replacing Spanglish "Her [Alice Jordan's] Spanglish fell somewhere between the twenty-second-century English Jeeves knew, and that Long Pass had brought to New Terra, and the Interworld with which Sigmund had grown up (Destroyer of Worlds ch. 44, p. 249). "...2514. Sigmund had turned twenty-four that year" (ibid, ch. 45 p. 257). Therefore, Sigmund Ausfaller was born in 2490, and apparently Interworld was the common language of Human Space by that time.. By 2850 it had replaced all regional languages on Earth. Nessus, a Puppeteer, complained Interworld was difficult for a non-human to learn and pronounce. See also languages, Wunderlander.
Reference: "The Soft Weapon", "Fly-By-Night", Destroyer of Worlds ch. 44, Ringworld chs. 1, 4, 8-9, 13, 21-2
A force field hemisphere in a park on Hearth, glowing like a pearl, containing couches. The dome appeared invisible from the inside, but acted as a projection screen. Explorers from the First Ringworld Expedition met Chiron there in 2850, and received a briefing on the Ringworld.
Apparently a radical group on Wunderland advocating political isolation from Human Space, perhaps opposed to the influence of the UN on their world. Sigmund Ausfaller thought them a potential customer, in 2641, for a stolen, heavily armed starship.