Seesaw a "teeter-totter". According to linguist Peter Trudgill, the term originates from the Nordic language word "tittermatorter". A "teeter-totter" may also refer to a two-person swing on a swing seat, on which two children sit facing each other and the teeter-totter swings back and forth in a pendulum motion. Both "teeter-totter" (from "teeter", as in "to teeter on the edge") and "seesaw" (from the verb "saw") demonstrate the linguistic process called reduplication, where a word or syllable is doubled, often with a different vowel. Reduplication is typical of words that indicate repeated activity, such as riding up and down on a
Known Space Nebula, Hugo, and Locus best novel awards. "Protector" (1973) and "The Ringworld Engineers" (1980) were nominated for the Hugo and Locus Awards. Niven has described his fiction as "playground equipment", encouraging fans to speculate and extrapolate on the events described. Debates have been made, for example, on who built the Ringworld (Pak Protectors and the Outsiders being the traditional favorites, but see "Ringworld's Children" for a possibly definitive answer), and what happened to the Tnuctipun. Niven also states that this is not an invitation to violate his copyrights, warning potential publishers and editors not to proceed without permission. Niven was