We must, then, try to remember Halley in context—not as a singular genius who emerged from a family of soap-boilers to discover a comet, but as a searching and broadly curious person who was also, like the rest of us, “a bubble on the tide of empire,” as Robert Penn Warren memorably put it.
That noted, Halley was brilliant. Here’s just one example of his use of lateral thinking, as discussed in John and Mary Gribbin’s book Out of the Shadow of a Giant: When asked to work out the acreage of land in every English county, Halley “took a large map of England, and cut out the largest complete circle he could from the map.” That circle equated to 69.33 miles in diameter. He then weighed both the circle and the complete map, concluding that since the map weighed four times more than the circle, the area of England was four times the area of the circle. His result was only 1 percent off from contemporary calculations.
Halley’s polymathic curiosity makes his list of accomplishments read like they’re out of a Jules Verne novel. He invented a kind of diving bell to go hunting for treasure in a sunken ship. He developed an early magnetic compass and made many important insights about Earth’s magnetic field. His writing on Earth’s hydrological cycle was tremendously influential. He translated the Arab astronomer al-Battānī’s tenth-century observations about eclipses, using al-Battānī’s work to establish that the moon’s orbit was speeding up. And he developed the first actuarial table, paving the way for the emergence of life insurance.
Halley also personally funded the publication of Newton’s three-volume Principia because England’s leading scientific institution, the Royal Society, “rashly spent all its publishing budget on a history of fish,” according to historian Julie Wakefield. Halley immediately understood the significance of the Principia, which is considered among the most important books in the history of science.* “Now we are truly admitted as table-guests of the Gods,” Halley said of the book. “No longer does error oppress doubtful mankind with its darkness.”
Of course, Halley’s ideas didn’t always hold up. Error still oppressed doubtful humankind （and still does）。 For example, partly based on Newton’s incorrect calculations of the moon’s density, Halley argued there was a second Earth inside of our Earth, with its own atmosphere and possibly its own inhabitants.
* * *
By the time Halley’s comet showed up in 1986, the scientific revolution’s approach to knowledge-building had proven so successful that even third graders like me knew about the layers of the earth. That day in the Ocala National Forest, my dad and I made a bench by nailing two-by-fours to sections of tree trunk. It wasn’t particularly challenging carpentry, but in my memory, at least, it took us most of the day. Then we started a fire, cooked some hot dogs, and waited for it to get properly dark—or as dark as Central Florida got in 1986.
I don’t know how to explain to you how important that bench was to me, how much it mattered that my dad and I had made something together. But that night, we sat next to each other on our bench, which just barely fit the two of us, and we passed the binoculars back and forth, looking at Halley’s comet, a white smudge in the blue-black sky.
My parents sold the cabin almost twenty years ago, but not long before they did, I spent a weekend there with Sarah. We’d just started dating. I walked her down to the bench, which was still there. Its fat legs were termite-ridden, and the two-by-fours were warped, but it still held our weight.
* * *
Halley’s comet is not a monolithic spherical miniplanet flying through space, as I imagined it to be. Instead, it is many rocks that have coalesced into a peanut-shaped mass—a “dirty snowball,” as the astronomer Fred Whipple put it. In total, Halley’s dirty snowball of a nucleus is nine miles long and five miles wide, but its tail of ionized gas and dust particles can extend more than sixty million miles through space. In 837 CE, when the comet was much closer to Earth than usual, its tail stretched across more than half of our sky. In 1910, as Mark Twain lay dying, Earth actually passed through the comet’s tail. People bought gas masks and anti-comet umbrellas to protect against the comet’s gases.
In fact, though, Halley poses no threat to us. It’s approximately the same size as the object that struck Earth sixty-six million years ago leading to the extinction of dinosaurs and many other species, but it’s not on a collision course with Earth. That noted, Halley’s comet will be more than five times closer to Earth in 2061 than it was in 1986. It’ll be brighter in the night sky than Jupiter, or any star. I’ll be eighty-three—if I’m lucky.
* * *
When you measure time in Halleys rather than years, history starts to look different. As the comet visited us in 1986, my dad brought home a personal computer—the first in our neighborhood. One Halley earlier, the first movie adaptation of Frankenstein was released. The Halley before that, Charles Darwin was aboard the HMS Beagle. The Halley before that, the United States wasn’t a country. The Halley before that, Louis XIV ruled France.
Put another way: In 2021, we are five human lifetimes removed from the building of the Taj Mahal, and two lifetimes removed from the abolition of slavery in the United States. History, like human life, is at once incredibly fast and agonizingly slow.
* * *
Very little of the future is predictable. That uncertainty terrifies me, just as it terrified those before me. As John Gribbin and Mary Gribbin write, “Comets were the archetypal unpredictable phenomenon, appearing entirely without warning, rousing superstitious awe in the eighteenth century to an even greater extent than eclipses.”
Of course, we still know almost nothing about what’s coming—neither for us as individuals nor for us as a species. Perhaps that’s why I find it so comforting that we do know when Halley will return, and that it will return, whether we are here to see it or not.
I give Halley’s comet four and a half stars.
OUR CAPACITY FOR WONDER
TOWARD THE END of F. Scott Fitzgerald’s novel The Great Gatsby, the narrator is sprawled out on a beach at night when he begins thinking about the moment Dutch sailors first saw what is now called New York. Fitzgerald writes, “For a transitory enchanted moment, man must have held his breath in the presence of this continent, compelled into an aesthetic contemplation he neither understood nor desired, face to face for the last time in history with something commensurate to his capacity for wonder.” It’s a hell of a sentence. A lot changed in Gatsby between the first manuscript and the finished book—in 1924, Fitzgerald’s publisher actually had galleys printed of the novel, then called Trimalchio, before Fitzgerald revised extensively and changed the title to The Great Gatsby. But in all of the editing and cutting and rearranging, that particular sentence never changed. Well, except that in one draft Fitzgerald misspelled the word aesthetic—but who hasn’t?
Gatsby took a circuitous route on its way to being one of the Great American Novels. The initial reviews weren’t great, and the book was widely considered to be inferior to Fitzgerald’s first novel, This Side of Paradise. In the New York Herald, Isabel Paterson wrote that Gatsby was “a book for the season only.” H. L. Mencken called it, “obviously unimportant” in the Chicago Tribune. The Dallas Morning News was especially brutal, writing, “One finishes The Great Gatsby with a feeling of regret, not for the fate of the people in the book, but for Mr. Fitzgerald. When This Side of Paradise was published, Mr. Fitzgerald was hailed as a young man of promise . . . but the promise, like so many, seems likely to go unfulfilled.” Yikes.