Before revision: For Larry Niven's novels The Integral Trees and The Smoke Ring, Niven designed a "freefall" environment, a gas torus ring of habitable pressure, temperature, and composition, around a neutron star; Brian Aldiss's Helliconia trilogy which has a very long year (called the "great year"), equivalent to 2,500 Earth years, where generations live & die within one season.
After revision: For Larry Niven's novels The Integral Trees and The Smoke Ring, Niven designed a "freefall" environment, a gas torus ring of habitable pressure, temperature, and composition, around a neutron star; Brian Aldiss's Helliconia trilogy has a very long year (called the "great year"), equivalent to 2,500 Earth years, where generations live & die within one season.