Synopsis
Book by Gilder George
Extrait
Chapter 1: Maxwell's Rainbow
"Nothing is too wonderful to be true."
-- James Clerk Maxwell, discoverer of electromagnetism
"Too much of a good thing can be wonderful."
-- Mae West
The supreme abundance of the telecosm is the electromagnetic spectrum, embracing all the universe of vibrating electrical and magnetic fields, from power line pulses through light beams to cosmic rays. The scarcity that unlocks this abundance is the supreme scarcity in physical science: the absolute minimum time it takes to form an electromagnetic wave of a particular length. Set by the permeability of free space, this minimal span determines the speed of light.
The discovery of electromagnetism, and its taming in a mathematical system, was the paramount achievement of the nineteenth century and the first step into the telecosm. The man who did it was the great Scottish physicist James Clerk Maxwell. In his honor, we will call the spectrum Maxwell's rainbow. Today most of world business in one way or another is pursuing the pot of gold at the end of it.
Arriving at the profound and surprising insight that all physical phenomena, from images and energies to chemical and solid bodies, are built on oscillation, Maxwell embarked on a science of shaking. For roughly a hundred and fifty years, this improbable topic has animated all physics. Another word for oscillation is temperature. Without the oscillations, the mostly empty matter of the universe would collapse in on itself. In theory, you can make the shaking stop, but only by making things cold indeed -- 273 degrees below zero Celsius, or zero Kelvin. So far unreachable even in laboratories, it is the temperature of the universe's heat death.
When things oscillate, they make waves, and in that magic moment the possibility of the telecosm is born.
Maxwell's genius was to realize that all waves are mathematically identical, and can be arrayed along a continuum known as the spectrum. The unity of the spectrum makes possible the ubiquity and interoperability of communications systems and thus enables the unification of the world economy in the new era.
The light your eyes can see is only a tiny slice of the range of "colors" that actually exist or can be created. They run from the background rumble of the universe at the low, or "dark" end, to shrieking gamma rays that can penetrate a planet at the high "bright" end. Each wavelength has its own distinct characteristics -- some are better at transmitting raw power, others for traveling long distances, others for carrying digital bits.
Slices of Maxwell's rainbow form the core of virtually every significant modern technology: 60-hertz household power cords and three kilohertz (thousand-cycle) telephones; 700 megahertz (mega is million) Pentium PCs; two gigahertz (billion) cellular phones and 200 terahertz (trillion) fiber-optic cables. The neurons in your brain, for their part, hum along at barely a kilohertz; thank the Lord for parallel processing. Dental X rays, at the other extreme, top a petahertz -- a thousand trillion cycles per second. The potential number of frequencies is literally infinite, limited only by how finely your technology can parse the rainbow.
Maxwell's theory informed his several immense tomes on electromagnetism. The fruit of a promethean life ended by cancer at age forty-eight, his work empowered titans such as Erwin Schroedinger, Hendrik Lorentz, Albert Einstein, and Richard Feynman to create the edifice of twentieth-century quantum and post-quantum physics.
As much as pure scientists hate the idea, however, it is engineers and entrepreneurs who finally ratify their work. Until theory is embodied in a device, it is really not physics but metaphysics. Newton's ideas burst forth as the industrial revolution. Quantum theory triumphed unimpeachably in the atomic bomb and the microchip. In contrast to the intriguing perplexities of particle physics -- Einstein's relativity, Murray Gell-Mann's quarks, Richard Feynman's quantum electrodynamics, Stephen Weinberg's grand unification, Schwartz's karass of superstrings -- Maxwell's rainbow may seem child's play. But as we approach the twenty-first century, the spectrum's infinite spread of capabilities is history's driving force.
Maxwell had transformed the mindscape of metaphor and analogy by which human beings grasp reality. For Newton's medley of massy and impenetrable materials, he substituted a noosphere of undulatory energies. And woven uniquely into the warp of nature was the resonating speed of light. As Maxwell and others discovered, the speed of light is a basic constant in our universe -- no matter the speed of the observor or the medium. Frequencies and wavelengths may change, but light speed delay -- the time it takes to propagate an electromagnetic wave -- never changes.
As we will see, light speed is both the crucial enabler and limit of the telecosm. Without it, radiation would be chaotic and uncommunicative. It would be noise that could not bear a signal. Yet communication can never exceed this speed, a fact that will keep us forever distant from other planets and even from ourselves.
There are no practical limits to the spectrum's range of possible wavelengths and frequencies. Nor is the spectrum expressed only by the physics of electromagnetic waves. Spectral frequencies translate into temperatures, into atomic signatures, and into photon energies.
Let the action begin by beating on a drum at a rate of once each second: one hertz. Translating these drumming "phonons" into electromagnetic form, a one-hertz frequency would command a theoretical wavelength of three hundred million meters. Applied to a single photon, its energy in electron volts would be Planck's quantum constant -- 6.63 times 10 to the minus 34th power, close to "Johnson noise," the background chill of the cosmos. Slowly accelerate the drumming to the fast be-bop rattle of a Max Roach or Buddy Rich, perhaps 16 beats per second. That is 16 hertz, around one fourth of the rate of an electrical power station. Suppose that your drumming skills are superhuman, moving at 3,000 beats per second; you are transferring the same number of oscillations that can be carried by a telephone wire. At some 30,000 hertz you have broken the sound barrier because you are sending out wave crests faster than they can be heard.
Nonetheless, you remain near the very bottom of the electromagnetic spectrum. At the other extreme are gamma rays, creatures of cosmic explosions and giant particle accelerators, a frequency of 10 to the 24th hertz. Their wavelength, 10 to the minus 22 meters, is small enough to get lost in an atom. Between Johnson noise and gamma rays is the telecosm, the gigantic span that Maxwell bridged with his mind, most of it now open to human use.
Above 14 gigahertz -- at wavelengths running from the millimeters of microwaves down to the nanometers of visible light -- is the new frontier of the millenium, empires of air and fiber that command some fifty thousand times more communications potential than all the lower frequencies we now use put together. A purely human invention, they provide the key arena of economic activity for the new century.
To put this huge span of frequencies in perspective, a factor of some 10 to the 25th stands between the lengths of the longest and shortest known forms of electromagnetic waves. As molecular biologist Michael Denton has observed: "A pile of ten to the twenty-fifth playing cards would make a stack stretching halfway across the observable universe." Seventy percent of the sun's light and heat occupies the band between near-ultraviolet and near-infrared -- the width of the edge of just one playing card in Denton's cosmic stack. This little sliver of the spectrum providentially sustains life. Maxwell opened the rest of it up for human use: the telecosm.
Copyright © 2000 by George Gilder
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