“The fact that we live at the bottom of a deep gravity well, on the surface of a gas covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be.”

“I myself have dreamed up a structure intermediate between Dyson spheres and planets. Build a ring 93 million miles in radius - one Earth orbit - around the sun. If we have the mass of Jupiter to work with, and if we make it a thousand miles wide, we get a thickness of about a thousand feet for the base.And it has advantages. The Ringworld will be much sturdier than a Dyson sphere. We can spin it on its axis for gravity. A rotation speed of 770 m/s will give us a gravity of one Earth normal. We wouldn't even need to roof it over. Place walls one thousand miles high at each edge, facing the sun. Very little air will leak over the edges.Lord knows the thing is roomy enough. With three million times the surface area of the Earth, it will be some time before anyone complains of the crowding.”

“Imagine a rotating sphere that is 8,000 miles in diameter, with a bumpy surface, surrounded by a 25-mile-deep mixture of different gases whose concentrations vary both spatially and over time, and heated, along with its surrounding gases, by a nuclear reactor 93 million miles away. Imagine also that this sphere is revolving around the nuclear reactor and that some locations are heated more during parts of the revolution. And imagine that this mixture of gases receives continually inputs from the surface below, generally calmly but sometimes through violent and highly localized injections. Then, imagine that after watching the gaseous mixture you are expected to predict its state at one location on the sphere one, two, or more days into the future. This is essentially the task encountered day by day by a weather forecaster.”

“Every living thing is, from the cosmic perspective, incredibly lucky simply to be alive. Most, 90 percent and more, of all the organisms that have ever lived have died without viable offspring, but not a single one of your ancestors, going back to the dawn of life on Earth, suffered that normal misfortune. You spring from an unbroken line of winners going back millions of generations, and those winners were, in every generation, the luckiest of the lucky, one out of a thousand or even a million. So however unlucky you may be on some occasion today, your presence on the planet testifies to the role luck has played in your past.”

“In the background is the hiss of the gas heater; we hear the sound without hearing it for, side by side, together and miles apart, we are deep in our books.”

“Miracles do happen. You must believe this. No matter what else you believe about life, you must believe in miracles. Because we are all, every one of us, living on a round rock that spins around and around at almost a quarter of a million miles per hour in an unthinkably vast blackness called space. There is nothing else like us for as far as our telescopic eyes can see. In a universe filled with spinning, barren rocks, frozen gas, ice, dust, and radiation, we live on a planet filled with soft, green leaves and salty oceans and honey made from bees, which themselves live within geometrically complex and perfect structures of their own architecture and creation. In our trees are birds whose songs are as complex and nuanced as Beethoven’s greatest sonatas. And despite the wild, endless spinning of our planet and its never-ending orbit around the sun–itself a star on fire–when we pour water into a glass, the water stays in the glass. All of these are miracles.”