Excerpt from Light by Bruce Watson, plus links to reviews, author biography & more

"We eat light, drink it in through our skins."
--James Turrell, Light and Space artist

INTRODUCTION

Galileo was bewildered. Toward the end of his life, a life that witnessed wondrous light none had seen before, the great scientist confessed one failure. Decades had passed since a friend had given him several of the stones Italians called "solar sponges." Soaking up sunlight, emitting a soft green glow, the stones convinced Galileo that Aristotle had been wrong about light. It was not some warm, ethereal element. Light could be as cold as the moon and as corporeal as water. But what was it?

Over the years, Galileo had learned to reflect light, to bend it, to amaze observers with telescopes that spotted ships two hours sail from Venice. Turning his telescope toward the night sky, he had been the first to see the moons of Jupiter and the rings of Saturn. Later he proposed the first experiment to clock the speed of light, bouncing lantern beams across the hilltops of Tuscany. Galileo never conducted his speed test. Other experiments, other trials demanded his attention, yet he continued to wonder about light. Shortly before his death, blind and broken, he admitted how he longed for an answer. Though under house arrest for heresy, he said he would gladly suffer a harsher imprisonment. He would live in a cell with nothing but bread and water if, upon emerging, he could know the truth about light.

The truth is that, despite three millennia of investigation by humanity's most brilliant detectives, light refuses to surrender all its secrets. As familiar as our own faces, light is the first thing we see at birth, the last before dying. Some, having seen a warm glow as they flirted with death, swear that light will welcome us to another life. "Painting is light," the Italian master Caravaggio noted, and each day light paints a mural that sweeps around the globe, propelling us into the morning. Ever since the Big Bang, light has been stealing the show. And for countless scientists, philosophers, poets, painters, mystics, and anyone who ever stood in awe of a sunrise, light is the show.

"If there is magic on this planet," the naturalist Loren Eisley wrote, "it is contained in water." Light, however, is the magician of the universe. Light makes darkness vanish and worlds reappear. Light opens each day with a blaring overture, then throws its wands to earth and casts diamonds on lakes and oceans. Each night, light's tricks make the stars seem alive. Seen through telescopes Galileo could never have imagined, light dances across the rings of Saturn, shapes gas clouds into crabs and horse heads, spirals from great galaxies and bursts from newborn stars. As reliable and relentless as time, light will begin tomorrow with another hurrah, then close the show with house lights, low and glimmering. Drawn to it as surely as any moth, we cannot live without it. "When the great night comes, everything takes on a note of deep dejection," psychologist Carl Jung wrote, "and every soul is seized by an inexpressible longing for light."

But what is light? What meaning have our brilliant detectives found in it? Is it God? Truth? Mere energy? Since the dawn of curiosity, these questions have been at the core of human existence. The struggle for answers has given light a life — and a biography — of its own. In human consciousness, light first appeared in stories of creation, stories spun in the glow of firelight or torch. From Genesis' immortal "Let there be light" to the Icelandic Edda that had God throwing embers into the darkness, light is the primal ingredient of every creation story. Following its mythical creation, Life matured into a mystery that intrigued philosophers from Greece to China. Was light atoms or shimmering eidola? Were we all, as the apostle Paul wrote, "children of light?" Just when each sage had light pinned down, the mystery rose again, posing further questions, fresher metaphors.

Excerpted from Light by S.J. Watson. Copyright © 2016 by S.J. Watson. Excerpted by permission of Bloomsbury USA. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.