Ringworld is a 1970 science fiction novel by Larry Niven, set in his Known Space universe and considered a classic of science fiction literature. Ringworld tells the story of Louis Wu and his companions on a mission to the Ringworld, an enormous rotating ring, an alien construct in space 186 million miles (299 million kilometres) in diameter. Niven later wrote three sequel novels and then cowrote, The opening chapter of the original paperback edition of Ringworld featured Louis Wu teleporting eastward around the Earth in order to extend his birthday. Moving in this direction would, in fact, make local time later rather than earlier, so that Wu would soon arrive in the early morning of the next calendar day. Niven was "endlessly teased" about this error, which he corrected in subsequent printings to show Wu teleporting westward. In his dedication to The Ringworld Engineers, Niven wrote, "If you own a first paperback edition of Ringworld, it's the one with the mistakes in it. It's worth money." After the publication of Ringworld, many fans identified numerous engineering problems in the Ringworld as described in the novel. One major one was that the Ringworld, being a rigid structure, was not actually in orbit around the star it encircled and would eventually drift, ultimately colliding with its sun and disintegrating. This led MIT students attending the 1971 Worldcon to chant, "The Ringworld is unstable!" Niven wrote the 1980 sequel The Ringworld Engineers in part to address these engineering issues. The second chapter refers to standard Earth gravity as 9.98 m/s2 (or even gives the unit as m/s [sic]), while standard Earth…