Academic history writing has blossomed amid a boomlet of themed science histories. These usually take a scientific phenomenon so taken for granted we don’t even notice it in our daily lives—color was explored in the titles Mauve, which is about the development of chemical dyes, and Bright Earth, which is about the theory of color as a scientific phenomenon and artist’s tool. Einstein’s great equation E = mc2 inspired an eponymously titled history of its origins and significance. After years or yet more about the Renaissance or Enlightenment, themed histories are a whiff of fresh stuff.

Like color, light is a physical phenomenon, the end result of more fundamental processes that our senses register as effects, leaving the ill-content mind to bewonder for causes. Interpreted pragmatically, light is something surgeons and factory assemblers desire in abundance and without shadow. Interpreted artistically, photographers like the effects of contrast more than light itself—in much the same way certain Chinese and Japanese artists and flower arrangers saw empty space as more important than object depicted. Painters think of light more often in terms of luminosity than physical state. Interpreted emotionally, lovers prefer just enough of it to see each other, and barkeeps know it sells more drams than Hemingway’s or anyone else’s clean-well-lightedness. It can arguably be said that light is the root of religion, a panorama of wonder that links light to life and cosmos to anthropos.

But shear it of awe and just what is this... stuff? Brian Clegg’s Light Years and Time Travel looks at light the phenomenon via the way it has been looked at. His “golly-gee-whiz, you-don’t say” first chapter beams us up from the mundane world of traffic lights and light bulbs (two of the surprisingly few objects in which so ubiquitous a phenomenon is identified by name) into the far reaches of contemporary physics—“slow glass”, Bose-Einstein condensates, tachyonic tunneling in which phenomenon occur at faster than the speed of light without altering the adjacent fabric of space and time.

Succulent morsels at the feast of the magic of science, but you can’t eat a whole book of it. So in Chapter Two he reels us back to the familiar solace of myth to slake our wonder: Daedalus, Theseus, the Egyptian sun-disk Aten, Helios on his four-horsed chariot. Without these touchstones of behavioral archaea, where would we be? Or more aptly, who?

Probably a lot more advanced than we already are, because Mr. Clegg then gives us a shock of reality: The first genuine scientific study of light was not by the geometry-loving Greeks or engineering-minded Romans, but by followers of the Chinese pragmatist Mo-Tzu [470-391 BC]. They measured the different reflections produced by flat and curved mirrors, and even more tantalizingly, noted that light shining through a tiny pinhole produced a weak upside-down image of an object—the forerunner of the “camera obscura” that became first pinhole photography and then today’s photo camera (which for all its advances still records images upside down, as too does the eye). The Greeks got stuck in the mud of a bad idea: that mind alone and not experiment were the taproot of surety. From this came another bad idea: Empedocles’ notion that light emanated from within the eye and left it to be reflected off the object, thence to return.

For a thousand years no one asked why, if this was so, there existed such a thing as darkness. In the 900s the Muslim philosopher Alhazen asked that word that’s doom to the demeanor of fixity—why, if light comes from the eye, does the eye hurt when something is very bright but not when it is faint? Alhazen correctly deduced that light came from the sun, and was either received directly by the eye or bounced off objects on the way. He also used the upside-down image produced by a pinhole to deduce that light traveled in straight lines.

European thinkers did not emulate their Muslim and Asian counterparts in placing observation above theory until two English monks came along in the 1200s. Robert Grosseteste asserted that mathematical explanation could describe physical fact. Roger Bacon earned in his time the legendary stature Einstein is accorded today, doing so with three books that not merely summed up knowledge of physical reality but did so using the razor of the founding principle of scientific thought: testing a hypothesis with experiment.

All this occurs before page 50. The next 196 pages are a fascinating chronology of how seemingly simple ideas and phenomenon were elaborated through experiment and logic—and many injections of bolt-from-the-blue inspiration—into the immense edifice of proposition that is science today. That in itself is a wondrous tale, but Mr. Clegg’s book sings because he shapes the shadowy bearers of ideas into real people, not so much of name and face but of self-faith and feeling. And humanity: Empedocles, for example, rated himself so highly that he wore the purple and gold of imperatorship; Roger Bacon suffered suspicion and rejection and prison on his way to legendry; Max Planck saw to the burials of all his progeny before he joined them himself.

There are tales tragic, tales bold; of this scientist born with all the proper social graces but in whose envious mouth a silver spoon turned to gall (Isaac Newton’s fierce enemy, the socially well-connected but not-as-bright Robert Hooke); Newton himself, a meager gentleman farmer until he commenced a line of experiment with a chance purchase of a new toy at the Simon-and-Garfunklish Stourbridge Faire—a prism—which inspired the first great “Theory of Everything” worthy the name. The great German writer Goethe whose Faust becried a human-centered vision of religion was also a scientist who, when he applied the same human centeredness to light, came up with an erroneous theory about color that raised one of the fundamental issues at the core of scientific endeavor: does truth exist by itself, or because a human perceives and articulates it? Is truth event, or is it us? When Newton related his findings about light, he described what light itself was like. When Goethe did the same, he described what the human perception of light was like. Unless you’ve read Newton, Goethe’s notion sounds pretty good.

The result was physics versus metaphysics, the upshot of which was the introduction of moral absolutism into science in much the same way religions introduce it into spirituality. Science and faith can coexist more or less contentedly when it comes to the effects and ephemera of existence—Einstein himself said that God does not play dice. But when it comes to the issue to which humankind seems most attracted—ultimate origin—science can be as unbendingly self-focused as religions. As Mr. Clegg plunges into modern physics his superb exposition is tinged throughout, not by him—he is too good a writer to assert himself above his subject—but by the convolutions to which theorists will go in order to deny a cause of existence that does not involve a human explanation. Science’s inability to accept any evidence beyond its own is remarkably similar to scripture’s inability—be it Bible, Qur’an, Upanishad, or Guru Granth—to accept evidence of a truth source different from what it claims of itself.

As one proceeds through Mr. Clegg’s advancing exposition, an unease grows that has nothing to do with the nobility of the subject he is exposing, nor the quality of his labor as he does so. Rather, it is an unease about the immense clench of behavior he documents arising: the inability to humble oneself in the face of what one knows. This is a criticism made often by the experimenter against the doctrinist, but now the doctrinist can say it of the experimenter in turn. Science does just about everything imaginable to avoid the word “Creation.”

On page 246 he descends us from the comforts of history to the uneasy questions of now. All along the quest has been the study of light. When he gets to Richard Feynman and his ponderously named theory of Quantum Electrodynamics (QED) a Pandora’s Box throws open, and from it flies the winged thing scientists like least: uncertainty. Around the cobwebs of past it flies, eating the moths of mind attracted to the flame. It seems, as Mr. Clegg says, uncertainty rules all, and light shall ever slide from grasp, inexplicable whether packet or wave. But wait, says Feynman, who in his life was the visualizer more than the visionary, if light is both particle and wave, and its entire life is a solitary bolt from electron to electron, it is never lost. It is passed on as light, but of a different kind—if it is felt as heat, it is really infrared light; if it is slowed or sped by the energy of the electron, the light changes energy, which if in the range of our eye, we see as color. In fact, Feynman says, the very atomic nucleus and orbital electron are kept from mating in annihilation by an exchange of light energy between them—light never lost, never gained but always there, and the entire universe exists because of it.

Fiat lux says the God of the religionist. Big Bang says the god of science. Now comes along Alan Guth, the conceiver of Inflation Theory, asserting that the universe can create itself without even any laws with which to do so.* Uncertainty out of chance, for the eyes of time to behold. Who’s to say what’s right?

So step back in the imagination for the briefest of moments to consider all that we have attained in our study of cellular activity, genetic structure, the fundamental properties of nature, the origins of the universe, the immensity of Why underlying all these. Can we bring ourselves to accept that what we know with all our Why, is, to the sumtotal of all that is, what the ant knows of the span of the human tide? So Why: Why is it so hard to cross the line between the words “physical universe” to the word “Creation” and admit to the possibility of an uppercase “C”? When one reads the extraordinary leaps of thinking that Alan Guth uses to propose that the sumtotal of existence, so boggling in its immensity and we so irrelevant but for our Why, creates its own rules as it creates itself, one cannot but see Goethe, refusing to give up the human as the center of the seen, thereby unseeing what is there.

*See Brad Lemley, “Guth's Grand Guess,” DISCOVER, Vol. 23 No. 4 (April 2002)