Scrith is a milky-gray translucent, nearly frictionless material. Scrith, usually written italicized as scrith, forms the walls and floor of the Ringworld. In Ringworld's Children it is additionally explained that it took the reaction mass of roughly 20 Jupiter masses to spin up the ring thus the combined mass of the planets of the original system was that much larger than our solar system's. The adventurers surmised that its construction consumed literally all the planets in that system, down to the last asteroid and/or moon, as the Ringworld star has no other bodies in orbit. The Ringworld is described as having a mass approximately equal to the sum of all the planets in our solar system. Niven himself thinks of the Ringworld as 'an intermediate step between Dyson spheres and planets.' The Ringworld could be regarded as a thin, rotating slice of a Dyson sphere, with which it shares a number of characteristics. Walls 1000 miles tall along the edges retain the atmosphere. The 'Other Ocean' has many maps of a single world: the Pak Homeworld. One of the large oceans, known as the 'Great Ocean', contains one-to-one maps of all of the inhabited worlds of known space. On opposite sides of the ring are two large deep saltwater oceans, placed in counterbalance to one another. The majority of the surface is land interspersed with shallow, freshwater seas.

Ringworld has a habitable flat inner surface equivalent in area to approximately three million Earth-sized planets.

It rotates, providing an artificial gravity equivalent to 99.2% of Earth's gravity by way of Centrifugal force. The Ringworld is an artificial ring about one million miles wide and approximately the diameter of Earth's orbit (which makes it about 600 million miles in circumference), encircling a Sol-type star. On Ringworld, time longer than a day is measured in falans, with 1 falan being 10 turns or 75 Ringworld days (93.75 Earth days), so 4 falans is slightly longer than 1 Earth year. G3 verging on G2 'barely smaller and cooler than Sol'.ħ.5 Ringworld days (225 hours, 9.375 Earth days)

Ringworld engineering Ringworld parameters RadiusĢ×10 27 kg (1.8×10 24 short tons) (1,250,000 kg/m², e.g.

Ringworld pak protector