“It was a sincere request for information-nothing more-I want you to convey to me whatever it is about sundials I’ve been too thick-headed to find very interesting.”

This seemed to calm Isaac down, though he did not apologize for having thought the worst about Daniel. He said something along the lines of: “Heavenly radiance fills the ?ther, its rays parallel and straight and, so long as nothing is there to interrupt them, invisible. The secrets of God’s creation are all told by those rays, but told in a language we do not understand, or even hear-the direction from which they shine, the spectrum of colors concealed within the light, these are all characters in a cryptogram. The gnomon-look at our shadows on the Green! We are the gnomon. We interrupt that light and we are warmed and illuminated by it. By stopping the light, we destroy part of the message without understanding it. We cast a shadow, a hole in the light, a ray of darkness that is shaped like ourselves-some might say that it contains no information save the profile of our own forms-but they are wrong. By recording the stretching and skewing of our shadows, we can attain part of the knowledge hidden in the cryptogram. All we need to make the necessary observations is a fixed regular surface-a plane-against which to cast the shadow. Descartes gave us the plane.”

And so from then onwards Daniel understood that the point of this grueling sundial project was not merely to plot the curves, but to understand why each curve was shaped as it was. To put it another way, Isaac wanted to be able to walk up to a blank wall on a cloudy day, stab a gnomon into it, and draw all of the curves simply by knowing where the shadow would pass. This was the same thing as knowing where the sun would be in the sky, and that was the same as knowing where the earth was in its circuit around the sun, and in its daily rotation.

Though, as months went on, Daniel understood that Isaac wanted to be able to do the same thing even if the blank wall happened to be situated on, say, the moon that Christian Huygens had lately discovered revolving around Saturn.

Exactly how this might be accomplished was a question with ramifications that extended into such fields as: Would Isaac (and Daniel, for that matter) be thrown out of Trinity College? Were the Earth, and all the works of Man, nearing the end of a long relentless decay that had begun with the expulsion from Eden and that would very soon culminate in the Apocalypse? Or might things actually be getting better, with the promise of continuing to do so? Did people have souls? Did they have Free Will?

Hereby it is manifest, that during the time men live without a common power to keep them all in awe, they are in that condition which is called war; and such a war, as is of every man, against every man. For WAR, consisteth not in battle only, or the act of fighting; but in a tract of time, wherein the will to contend by battle is sufficiently known.

-HOBBES,Leviathan

NOW WALKING OUT ONTOthe upperdeck to find Minerva sailing steadily eastwards on calm seas, Daniel’s appalled that anyone ever doubted these matters. The horizon is a perfect line, the sun a red circle tracing a neat path in the sky and proceeding through an orderly series of color-changes, red-yellow-white. Thus Nature. Minerva -the human world-is a family of curves. There are no straight lines here. The decks are slightly arched to shed water and supply greater strength, the masts flexed, impelled by the thrust of the sails but restrained by webs of rigging: curve-grids like Isaac’s sundial lines. Of course, wherever wind collects in a sail or water skims around the hull it follows rules that Bernoulli has set down using the calculus-Leibniz’s version. Minerva is a congregation of Leibniz-curves navigating according to Bernoulli-rules across a vast, mostly water-covered sphere whose size, precise shape, trajectory through the heavens, and destiny were all laid down by Newton.

One cannot board a ship without imagining ship-wreck. Daniel envisions it as being like an opera, lasting several hours and proceeding through a series of Acts.

Act I: The hero rises to clear skies and smooth sailing. The sun is following a smooth and well-understood c?lestial curve, the sea is a plane, sailors are strumming guitars and carving objets d’art from walrus tusks, et cetera, while erudite passengers take the air and muse about grand philosophical themes.

Act II: A change in the weather is predicted based upon readings in the captain’s barometer. Hours later it appears in the distance, a formation of clouds that is observed, sketched, and analyzed. Sailors cheerfully prepare for weather.

Act III: The storm hits. Changes are noted on the barometer, thermometer, clinometer, compass, and other instruments-c?lestial bodies are, however, no longer visible-the sky is a boiling chaos torn unpredictably by bolts-the sea is rough, the ship heaves, the cargo remains tied safely down, but most passengers are too ill or worried to think. The sailors are all working without rest-some of them sacrifice chickens in hopes of appeasing their gods. The rigging glows with St. Elmo’s Fire-this is attributed to supernatural forces.

Act IV: The masts snap and the rudder goes missing. There is panic. Lives are already being lost, but it is not known how many. Cannons and casks are careering randomly about, making it impossible to guess who’ll be alive and who dead ten seconds from now. The compass, barometer, et cetera, are all destroyed and the records of their readings swept overboard-maps dissolve-sailors are helpless-those who are still alive and sentient can think of nothing to do but pray.

Act V: The ship is no more. Survivors cling to casks and planks, fighting off the less fortunate and leaving them to drown. Everyone has reverted to a feral state of terror and misery. Huge waves shove them around without any pattern, carnivorous fish use living persons as food. There is no relief in sight, or even imaginable.

–There might also be an Act VI in which everyone was dead, but it wouldn’t make for good opera so Daniel omits it.

Men of his generation were born during Act V*and raised in Act IV. As students, they huddled in a small vulnerable bubble of Act III. The human race has, actually, been in Act V for most of history and has recently accomplished the miraculous feat of assembling splintered planks afloat on a stormy sea into a sailing-ship and then, having climbed onboard it, building instruments with which to measure the world, and then finding a kind of regularity in those measurements. When they were at Cambridge, Newton was surrounded by a personal nimbus of Act II and was well on his way to Act I.

But they had, perversely, been living among people who were peering into the wrong end of the telescope, or something, and who had convinced themselves that the opposite was true-that the world had once been a splendid, orderly place-that men had made a reasonably trouble-free move from the Garden of Eden to the Athens of Plato and Aristotle, stopping over in the Holy Land to encrypt the secrets of the Universe in the pages of the Bible, and that everything had been slowly, relentlessly falling apart ever since. Cambridge was run by a mixture of fogeys too old to be considered dangerous, and Puritans who had been packed into the place by Cromwell after he’d purged all the people he did consider dangerous. With a few exceptions such as Isaac Barrow, none of them would have had any use for Isaac’s sundial, because it didn’t look like an old sundial, and they’d prefer telling time wrong the Classical way to telling it right the newfangled way. The curves that Newton plotted on the wall were a methodical document of their wrongness-a manifesto like Luther’s theses on the church-door.