Picturing the Phase Ring.

''It is difficult to get one's mind around the scope of the Niven Ring and how it works. For the benefit of myself and any one else boggled by the concept, I present these quotes by Larry Niven himself, describing his Ringworld as seen by the main character of his story, Louis Wu. All the following quotes are by Niven, from his book Ringworld published by DelRay. This is basically how our characters will experience the Ring.''

~ http:// "The Ringworld had no horizon. There was no line where the land curved away from the sky. Rather, earth and sky seemed to merge in a region where details the size of continents would have been mere points, where all colors blended gradually into the blue of sky. The vanishing point held his eyes fixed. When he blinked, as he finally did, it was with deliberate effort."

~

"Darkness fell quickly. A black shadow swept suddenly across the giant mountain. In seconds it was gone. The sun was only a golden sliver now, cut by blackness. And something took shape in the darkening sky.

An enormous arch.

Its outline grew rapidly clear. As the land and sky grew dark, the true glory of the Ringworld sky emerged against the night.

The Ringworld arched over itself in stripes of baby blue swirled with white cloud, in narrower stripes of near-black. At its base the arch was very broad. It narrowed swiftly as it rose. Near the zenith it was no more than a broken line of glowing blue-white. At the zenith itself the arch was cut by the otherwise invisible ring of shadow squares."

~

"The shadows were funny; the light was funny. Louis looked up and found a white sliver of noonday sun...

To his left all was darkness, deepening with distance. The missing horizon was a blackness born of night and chaos, beneath a navy sky in which outlines of the Ringworld arch glowed faintly.

To the right, spinward, was full day.

Dawn was different on the Ringworld."

~

"At the zenith swarmed a ring of black rectangles. The one that hid the sun was framed in a pearly coronal glow. The blue Ringworld formed a paraboloid arch over it all, framed against a star-dotted sky.

It looked like something done with a Build-A-City set, by a child too young to know what he was doing...Now, overhead, a brighter glow along one edge of the central shadow square showed that dawn was near...

The line dividing day from night is called the terminator. On Earth, the terminator is visible from the Moon; it is visible from orbit; but it cannot be seen from the Earth's surface.

But the straight lines dividing light from dark on the arch of the Ringworld were all terminators.

From spinward, the terminator line swept towards the flycycle fleet. From ground to sky it ran, from infinity-port to infinity-starboard. It came on like destiny made visible, a moving wall too big to go around. It arrived. The corona brightened overhead, then blazed as the withdrawing shadow square exposed a rim of solar disc. Louis contemplated the night to his left, the day on his right, the terminator shadow receding across an endless plain. A strange dawn, staged for Louis Wu the tourist."