The Universe Within: Discovering the Common History of Rocks, Planets, and People

Each galaxy, star, or person is the temporary owner of particles that have passed through the births and deaths of entities across vast reaches of time and space. The particles that make us have traveled billions of years across the universe; long after we and our planet are gone, they will be a part of other worlds.

There is something almost magical to the notion that our bodies, minds and ideas have roots in the crust of Earth, water of the oceans, and atoms in celestial bodies. The stars in the sky and the fossils in the ground are enduring beacons that signal, though the pace of human change is ever accelerating, we are but a recent link in a network of connections as old as the heavens.

The story of the poles is that of the entire planet. Our present—with its polar ice—is an aberration. For most of history our planet was warm, almost tropical. If the rocks of the world are a lens, they reveal that our modern, relatively cold landscape is not the normal state of affairs for the planet. In this great cooling lies one of the major events that shaped our bodies, our world, and our ability to see

North America and Europe are getting farther apart by 1.5 centimeters per year. Australia is heading for Hawaii at about 7 centimeters per year. The plates on our planet move about as fast as hair grows on our scalps.

Like a sixty-year-old person on actuarial charts, the habitable Earth is three-quarters of the way through its calculated life expectancy. Earth is about 4.57 billion years old, and the laws of stellar physics tell of another billion years before the sun expands to the point that it bakes the possibility for life off the planet.

Our body dries out with every passing year; newborns are about 75 percent water, not much different from an average potato.