The third planet in Sol System. It has one moon, Luna. The UN is the world government. Humans native to Earth are called Flatlanders. The Human population was stabilized at 18 billion in the mid-21st century, and remained so in 2850. By that year, city lights drowned starlight over most of the Earth, and instantaneous planet-wide travel via transfer booth had caused a thorough homogenization of Earth cultures.
A plant widespread on the Ringworld. It grows as a hedge in a row of triangles. A woody stem grows at a forty-five degree angle, up from the root to sprout a crown of leaves, then down at the same angle to a cluster of roots. A similar plant exists on Gummidgy, but does not have elbow root's Earth-like colors of brown bark and green leaves.
A liquid plastic which is hardened by running electricity through it.[Spoiler alert: Ringworld] The First Ringworld Expedition used such a plastic to anchor Nessus' flycycle in place inside the flying building dubbed Improbable, for thrust; to fasten the bulb at the end of the shadow square wire to the Improbable; and finally, to fasten the shadow square wire to the wrecked starship Lying Bastard as a tow line.
On Earth until at least 2200, the common international language of business. By the mid-2300s it had been replaced in Sol System by Spanglish, and in the hyperdrive era (after 2411) it was replaced throughout Human Space by Interworld. English remained in use by Concordance Colonists, and later by New Terrans, as their common language. Louis Wu studied English in school in his youth, perhaps circa 2670, and in 2658 Sigmund Ausfaller remembered Shakespeare plays in English.
Reference:Fleet of Worlds, Destroyer of Worlds, Ringworld ch. 1
Puppeteers are trained in childhood for a conditioned reflex, the "explosion reflex". When a Puppeteer senses an explosion or oncoming impact, he curls himself into a ball, folding his legs underneath and tucking his head tightly between his forelegs. A Puppeteer also typically adopts this posture if he feels threatened but can take no immediate useful action.
[Spoiler alert: Ringworld] On the Ringworld there is no Coriolis force, so normal hurricanes do not form. But above a large meteorite puncture, a vast vertical hurricane may form; a normal hurricane turned on its side, a storm which from certain angles looks like a Human eye. The eye storm encountered in 2851, by the First Ringworld Expedition, apparently disrupted planned weather patterns over a vast area. Numerous areas were observed where the terrain had been eroded down to the bare scrith foundation, perhaps up to tens of thousands of miles from the center of the first such storm encountered. The eye storm was at least a hundred miles long, and forty miles high. Flying into the "iris" at the center of the storm, the explorers found themselves flying through a black tunnel continually lit by lightning. Directly above the meteorite puncture was a large funnel shape where air was sucked down into the hole. Teela Brown was caught by this cyclone, and escaped only because she accidentally activated the emergency thrust on her flycycle, which flew her out of the storm.