A Star Shall Fall

They gave an impression of agreeable uniformity in their somber-colored coats, so very different from the young gallants of London’s beau monde who took every opportunity to quarrel. Nothing could be further from the truth. Nullius in verba was their motto: on the words of no one. This was the temple of facts, of careful observation and even more careful reasoning; the men of the Royal Society of London, the premier scientific body of the Kingdom of England, were no respecters of ancient authority. They respected only Truth. And when they found themselves in disagreement as to what that Truth was, their arguments could grow very heated indeed.

But there was little to argue in the second piece of that day’s business, presented by Oxford’s new Savilian Professor of Astronomy. In all honesty, hardly any men there had the capacity to debate it; the proof hinged on Newton’s Philosophiae Naturalis Principia Mathematica, which fewer of them understood than pretended to. Edmond Halley’s calculus therefore meant little to them. The fundamental point, however, was clear.

The orbit of a comet was not a parabola, but an ellipsis. And that meant that a comet, having departed from view, would in the fullness of time return.

A point that held rather a high degree of interest for two members of Halley’s audience.

“The measurements made by Flamsteed at Greenwich in 1682 are exceptionally precise,” the professor said, with a nod that acknowledged the contributions of the absent Astronomer Royal. “They provide us with a basis for examining the less-precise accounts of cometary apparitions in the past—1607, 1531, 1456, and so on.”

Back to the days of the Stuart kings, and the Tudors, and the Lancastrians. Many here today remembered the comet twenty-three years before, but a man’s beard would have to be gray indeed for him to have seen any of the others Halley named.

The one member of his audience who could claim that distinction had no beard at all. He was a young gallant more often found haunting the halls of London’s fencing masters, and his friends would have been surprised to see him in such sober costume, attending with hawklike intensity to the dull minutiae of astronomical mathematics.

Though not half so surprised as they would have been, had they ever seen their friend’s true face.

“A question, if you please,” the gallant said, interrupting Halley’s presentation of his Astronomiae cometicae synopsis, and drawing a swift frown from Newton. “Could anything divert the comet from its path?”

The Savilian Professor’s well-rehearsed presentation faltered. “I beg your pardon?”

“You say the comet travels far away from the sun, returning only every seventy-five years, or seventy-six. Could anything prevent that return, sending it out into space?”

Halley’s mouth opened and shut several times without anything coming out. “I suppose,” he said at last, with bewildered uncertainty, “that a large mass might exert gravitational force upon the cometary body, perturbing its path such that the return would not occur as expected. But to make it depart entirely… why, sir, would you be concerned with such a thing?”

Now all eyes in the room were upon the gallant—save for those belonging to Lord Joseph Winslow, who’d brought him there as a guest. Winslow had a most peculiar expression on his face, as if he wished dearly that his companion had not interrupted with such a bizarre question… but he also craved Halley’s answer.

“It seems to me,” the young gallant said, “that the eccentric wanderings of such a body might pose a danger to us here.”

A startled voice came from elsewhere in the audience. “If the orbits aligned unfavourably—could a comet strike the Earth?”

“Nonsense.” Newton’s sharp reply cut them all off like a blade. “The Lord designed the heavens to His purpose; if it should come to pass that anything in them brings calamity to the Earth—as may have occurred at the Deluge—then it will likewise be the Lord’s will. We may conclude, therefore, that there is no need for diversion of a comet’s path.”

The gallant was brave indeed, for he pressed his point, even in the face of Newton’s displeasure. “But what of smaller threats? Have not natural disasters been ascribed to the influence of comets? If one should—”

“Enough of this.” The President of the Royal Society stood, glaring at Winslow’s guest. “Comets are mechanical bodies, obeying the laws of motion and universal gravitation; if they have any effect beyond that, it is beneficial, distributing vapors that fuel the processes of vegetation and putrefaction on Earth, and perhaps supplying the spiritous component of air. Your fears are foolish, and you will waste no more of our time with them.”

Sir Isaac Newton had a piercing eye; but so, too, did the young gallant. He stood, not breaking his gaze from the great man’s, and made a curt bow before exiting the room. Winslow murmured his apologies and followed.