You would surely sleep later if it weren’t for the light. Streaming in the window, it is more piercing than usual. Neither your eyepatch nor a sock laid across your brow can block it, so you rise and blink away the darkness. Your alarm clock’s LED display tells you the time, while the light from your smart phone yanks you back into the world with news, mail, messages. . . But once your day begins, light is no longer a mere messenger. Now it becomes your servant, your secretary, your miracle worker.
While a laser diode plays a CD, the invisible light of microwaves heats your coffee. Infrared light toasts your bagel, and over breakfast, the light from your e-reader draws you like a moth to a flame. Once at work, light guides the mouse on your computer and the laser inside your printer. For the rest of the day, light performs wonders all around you — scanning images, reading bar codes, restoring eyesight, beaming videos, documents, and data around the globe.
Welcome to the Age of Light. Other ages, other building blocks have come and gone. Stone left stirring ruins. Bronze smelted sword and shield. Iron forged a future that turned ordinary tools into industries, leading to the ages of Steam, Coal, and Oil. With Oil’s kingdom battling over dwindling pools of petrol, a fresh resource — cheap, portable, limitless – has arisen to run the world. From here on in, we are, as the Apostle Paul wrote, “children of light.” (See The Light Poetic)
I am writing this in the dark. Often, when the light of the world is too distracting, I drag a chair into an upstairs closet and close the door. Time was when writing in the dark was impossible, but this laptop screen, its light polarized into on-off pixels that form these words, rivets my attention like a sunrise. It was here in the dark that I learned to feel light’s vitality, and to understand how this eternal force has become the Deus ex Machina of the 21st century.
Light has always beguiled humankind. The earliest creation myths explained First Light as coming from God’s eyes, his laugh, even his armpit. Neolithic civilizations built temples — at Stonehenge, Machu Picchu and elsewhere — to track the solstices. The pre-Socratic philosophers of Greece and the Mohist thinkers of early China were the first to secularize light, studying its ricochets and marveling at inverted images projected through pinholes.
On through the centuries, as religion wove light into a symbol of power and paradise, light slowly yielded its secrets. By 1000 CE, the Arab scientist Ibn-al-Haytham, expanding on the early optics of Euclid and Ptolemy, was charting how light reflected, refracted, and changed the color of everything it touched. Translated into Latin, his seven-volume study of light inspired Kepler, Galileo, and Newton. (See The Light Historic)
The long path from Newton and his prisms to you and your laser pointer is illuminated by geniuses. Faraday. Maxwell. Einstein. Feynman. Yet even as it was measured and mastered, light retained its beauty. Nothing out of Edison’s lab supplanted sunrise, and no prism ever rivaled the rainbow. Well into the floodlit 20th century, there seemed to be no new light under the sun. And then suddenly, there was — a light brighter than the sun.
On May 16, 1960, in the hills overlooking Malibu, California, the Age of Light was born. The first laser pulse lasted just a fraction of a second. Even fellow engineers at Hughes Laboratories
scoffed at inventor Theodore Maiman’s obsession with “coherent light.” “What would Hughes do with a laser?” some asked. Was this some sci-fi death ray? the press wondered. But lasers were soon carrying voices, removing tumors, and bouncing beams off the moon. Refined by Quantum Electrodynamics, the laser has become cheap, portable, and ubiquitous. As if updating Milton in Paradise Lost — “Hail, Holy Light” — we have made lasers our “light fantastic,” using them to etch, probe, heal, measure, scan, amaze, and enthrall. Annual festivals of light are now held around the world. (See The Light Fantastic) LEDs have expanded light’s aura, their beams now shooting out of bike helmets, keychains, shower heads, smart phones, and dozens more devices. Here in the Age of Light, you wouldn’t be surprised to see a bear come through the woods holding an LED flashlight.
Yet we have only begun to tap light’s power. Since 1997, fourteen Nobel Prizes for Physics have gone to the latest research in light. Laser cooling. Light-gathering CCD’s. Fiber optics. Quantum optics. And in 2014, the white LED. In the coming decade, as University of Arizona physicist Thomas Miltser told me, “probably anything you can imagine doing with light can happen.” (See The Light Astonishing)
In recent years, light has been slowed to a dead stop. Diverted around objects known as “meta-materials,” light has flirted with invisibility. Amped up to temperatures found inside the sun, light has created “ignition,” solar fusion that promises, once affordable, to provide the almost infinite energy of stars. The emerging field of optogenetics is learning to trigger neurons deep in the brain, treating depression and other misfires with light alone. The first integrated circuits switched by photons may soon run supercomputers, if not laptops, with pure light. Some even talk of using quantum light’s entanglement, the instantaneous shift of photons across vast distances, to teleport material. Einstein called this “spooky action at a distance.” You know it as “Beam me up, Scotty!”
Throughout 2015, the United Nations observed “The International Year of Light.” A variety of events around the world – seminars, workshops, elementary fun with prisms — celebrated the eternal force we too often take for granted. Light’s international year is over now, but the Age of Light continues to shine. Light may awaken you too early tomorrow, but once you’re awake, it will drive your morning, your evening, your future. Hail Holy Light, particle, wave, and wonder. Now if I can just find my way out of this closet…