30 hours = one Ringworld day

1 Ringworld rotation = 7½ days

75 days = 10 turns = 1 falan

Mass = 2 x l0exp30 grams

Radius = .95 x l0exp8 miles

Circumference = 6 x l0exp8 miles

Width = .997 x l0exp6 miles

Surface area = 6 x l0exp14 square miles = 3 million times the surface area of the Earth

Surface gravity = .992 G (spin)

Spin velocity = 770 miles/second

Rim walls rise inward, 1000 miles.

Star: G3 verging on G2, barely smaller and cooler than Sol

Recent arrivals

Louis Wu: Earth born. First and second Ringworld expeditions.

Teela Brown: Earth born, of a line bred for luck by Piersons puppeteer manipulation. Turned protector in The Ringworld Engineers, and now deceased. First Ringworld expedition.

Nessus: Piersons puppeteer, the Hindmosts partner and mate. Led the first Ringworld expedition.

The Hindmost: Piersons puppeteer, once Chief-in-Command of his species. Led the second Ringworld expedition.

Chmeee, once Speaker-to-Animals: Kzin. First and second Ringworld expeditions.

Roxanny Gauthier: Earth born, Detective-One in the ARM. Served aboard Snail Darter and Gray Nurse.

Oliver Forrestier: Wunderland born, Detective, ARM. Served aboard Snail Darter and Gray Nurse.

Claus Raschid: Earth born, Detective-Two, ARM. Served aboard Snail Darter and Gray Nurse.

Detective-Major Schmidt: Earth born. Served aboard Gray Nurse.

Wes Carlton Wu: Earth born, Flight Captain aboard Koala.

Tanya Haynes Wu, Earth born, Purser aboard Koala.

Ringworlds children

Seeker: species unknown, last seen with Teela Brown.

Acolyte: Kzin, Chmeees exiled son.

Bram: Vampire turned protector, ruler of the Repair Center for countless aeons until killed by Tunesmith with Louis Wus help.

Wembleth: species unknown, Ringworld-born traveler.

Tunesmith: Night Person (Ghoul) turned protector.

Kazarp: Night Person, Tunesmiths son.

Hanuman: Hanging Person turned protector.

Valavirgillin: Machine People, represents Farsight Trading.

Proserpina: surviving Pak protector.

The Penultimate: Pak protector, long dead.

Szeblinda: Hinsh. Giraffe People

Kawaresksenjajok: City Builder

Fortaralisplyar: City Builder

Aerobrake: To shed velocity by passing through a planetary atmosphere.

Antispin: Direction opposite the Ringworlds direction of spin.

Arch: The Ringworld as seen from anywhere on its surface.

ARM: Once the Amalgamation of Regional Militia; for several hundred years, the United Nations armed forces. Jurisdiction was originally limited to Earth-Moon system.

Autodoc: Any system built to perform automated medical operations.

Belter: Citizen of the asteroid belt, Sol system.

Canyon: A world of human space, once Patriarchy property.

Carlos Wus autodoc: An experimental medical system first seen in "Procrustes".

Droud: A small device that plugs into the skull of a current addict. Its purpose: to meter a current flow to the pleasure center of the users brain.

Elbow root: A ubiquitous Ringworld plant. Grows as a kind of natural fence.

Experimentalist: A Piersons puppeteer political faction now out of power.

Eyestorm: The pattern of winds that forms above a puncture in the Ringworld floor. A tornado on its side. (Hurricanes and tornadoes are impossible on the Ringworlds flat surface.)

Fleet of Worlds: The homeworld of the Piersons puppeteer species, and four more worlds sequestered for farming, all occupy a Kemplerer rosette moving at near lightspeed.

Flup: Seabottom ooze.

Flycycle: A one- or two-LE flying device.

Fringe War: All the spacegoing species of known space seem to have sent ships to Ringworld system. Bram, when he was in command of the Repair Center, shot them down if they approached too close. Tunesmith hasnt done that, and the Fringe War is currently in a cold state.

General Products: A company owned by Piersons puppeteers that sold mostly spacecraft hulls. Dissolved two hundred years ago.

The Great Ocean: One of two salt seas on the Ringworld, measuring six hundred times the surface area of the Earth.

Grippy: An all purpose hand tool.

Home: A world of human space, unusually Earthlike.

Hot Needle of Inquiry: Second ship (of Experimentalist design) to reach the Ringworld.

Human space: The region of stars explored by humanity.

Known space: The region of the universe known to explorers who communicate with humanity.

LE (Legal Entity): Any entity (human or not, organic or not) legally entitled to civil rights.

Long Shot: Prototype Quantum II hyperdrive spacecraft, first ship to visit the galactic core.

Lying Bastard: First ship (of Experimentalist design) to reach the Ringworld.

Map of Earth (or Mars, Kzin, Kdatlyno, etc.): The Great Ocean is scattered with maps of nearby inhabited worlds at one-to-one scale, complete with local ecologies as of the time the Ringworld was built.

Meteor defense: Ringworld systems can cause a solar flare, and a superthermal laser effect within the flare. Energy output is awesome, but the effect is slow.

N-child: Lineal descendant.

Outsider hyperdrive or Hyperdrive: A means of faster-than-light travel common in known space.

Patriarchy: The Kzinti interstellar empire.

Port: To the left as one looks spinward.

Quantum II hyperdrive: An advanced experimental faster-than-light system, puppeteer designed, first seen in "At the Core." One Ringworld day under QII hyperdrive = 1440 light years.

Repair Center: The ancient center of Ringworld repair, maintenance, and control, housed beneath the Map of Mars on the Great Ocean.

Rishathra (reshtra, etc.): Sexual practice outside ones own species but within the intelligent hominids.

Scrith: Ringworld structural material. Scrith underlies all the terraformed and contoured inner surface of the Ringworld. The rim walls are also of scrith. Very dense, with a tensile strength on the order of the force that holds an atomic nucleus together.

Sheathclaws: A world held by humans and Kzinti together.

Spill mountains: Mountains standing against the rim wall, the outflow of the rim spillpipes. One stage in the circulation of flup.

Spin or Spinward: In the direction of rotation of the Ringworld. (Against the rotation of the sky.)

Starboard: To the right as one looks spinward.

Stasis field: Human technology. An induced state in which time passes very slowly. Ratios can be as high as a billion years of real time to a few seconds in stasis. An object in stasis is very nearly invulnerable.

Stepping disks: Puppeteer technology, an advanced form of teleportation.

Stet: Leave it alone; accept as written; make no change; restore.

Tanj: An expletive, once shorthand for "There aint no justice."

Thruster: Reactionless drive. In human space, thrusters have generally replaced fusion rockets on all spacecraft save warcraft.

Vishnishtee (Vashneesht, Vasnesht, Vasneesit, etc.): Wizard or protector.