The atomic age began 78 years ago today, on July 16, 1945, with the first-ever atomic bomb explosion, the Trinity Test near Alamogordo, New Mexico. This is how I described that momentous event in my novel The Oppenheimer Alternative:

Chapter 15

From The Oppenheimer Alternative by Robert J. Sawyer

I am sure that at the end of the world—in the last millisecond of the earth’s existence—the last human will see what we saw.

—George Kistiakowsky

At 5:29 on Monday morning, July 16, 1945, the one-minute-warning rocket twisted up into a predawn sky, adobe-pink to the east, stygian to the west.

“Lord, these affairs are hard on the heart,” Oppie said as much to himself as to the other men present—and then, tilting his head, conceded that there really had never before been such an affair. He gripped a rough-hewn oak beam with one hand, his fingers wraith-like. With his other hand he held the four-leaf clover Kitty had given him before he’d left for this test site, a place he himself had code-named “Trinity.” Although a trained botanist, his wife still felt there was luck in a mutant plant.

Thirty seconds later, four blood-red lights flashed on the console in front of Oppie in the concrete bunker ten thousand yards south of—a neologism, words shoved together like protons in a nucleus—“ground zero.” On his right a young physicist from Harvard stood by the knife switch that if opened would abort the test. The thing had its own momentum now, an electric timer ticking away; no one would go down in history as the individual who had set off the first atom bomb, but one man could still stop it.

The team at Los Alamos had come up with two different bomb designs. The first was a simple uranium-gun scheme deemed so foolproof that, as Leo Szilard had observed to Oppie, it didn’t require any testing. But Uranium-235, despite all efforts to efficiently separate it from U-238, was still available in such minuscule amounts that a second system was developed that instead used plutonium, which could be produced in comparatively large quantities. The alternative design required much more complex bomb hardware, and that was what they were about to test. Bob Serber had dubbed this spherical bomb type “Fat Man,” after the Sydney Greenstreet character in The Maltese Falcon. It used a revolutionary implosion system perfected—or so it had seemed until two days ago—by George Kistiakowsky. But a trial run early Saturday in the Pajarito Canyon, using a dummy Fat Man with a core of conventional explosives, had failed.

In the real Fat Man to be fired today, the plutonium core had been molded into a sphere the size of a softball. Surrounding it was a shell of thirty-two explosive castings called “lenses” because they’d been engineered so that the force of their explosions would be focused on the central sphere. With each lens detonating simultaneously, the spherical shockwave blowing inward should implode the core to tennis-ball size, forcing the plutonium into criticality. But the lenses in Saturday’s test bomb had apparently developed astigmatism.

Leslie Groves, military head of the Manhattan Project, and Vannevar Bush, in charge of the Office of Scientific Research and Development, and therefore its civilian head, had arrived as scheduled Saturday noon, and both were furious at the news.

Oppie tried to keep his cool in front of them—in front of everyone—but it finally all proved more than he could take. So much work, so much time, so near to success, but instead of a bloom of light, nettles in his fist. He’d broken down in front of Kistiakowsky, his tears the only moisture this desiccated area inauspiciously known as La Jornada del Muerto, The Workday of the Dead, had seen in weeks.

Kisty contended the failure was perhaps due to the use of substandard lenses, the best castings—free of significant bubbles and cracks—having been saved for the real thing, and he bet Oppie a month’s salary against ten dollars that everything would go fine today.

Late last night, Oppie, having recovered his composure enough to wax philosophic, had shared his own translation of a passage from the seven-hundred-stanza Bhagavad Gita with long-faced, bespectacled Vannevar Bush and visiting advisor I.I. Rabi, compact and trim, who had won last year’s Nobel Prize in physics:

“In sleep, in confusion, in the depths of shame,

“The good deeds a man has done before defend him.”

But rain, sheets of it, torrents, had begun at oh-two-hundred hours, the very heavens weeping.

Right now, Truman, Churchill, and Stalin were arriving at Potsdam, near Berlin, for the first Allied-leaders’ summit since the Nazi surrender. Truman desperately wanted a successful test so that he—the Commander in Chief, as Oppie had said, not some back-door sneak—could tell the Soviet premier that the Americans now had a working atomic bomb whose imminent use on Japan would surely end the Pacific war. The test had to go ahead now—but rain would drive radioactive particles down to the ground instead of letting them dissipate.

Groves loudly excoriated the meteorologist—who had, in fact, clearly warned the general days ago of the impending storm. Still, the man now felt the torrent would abate by dawn. Groves growled, “You’d better be right or I’ll have you hanged,” and he made the hapless soul sign his written forecast.

Then, just before 3:00 a.m., Groves got on the phone to the Governor of New Mexico, a servant rousting the sixty-six-year-old from bed. Oppie heard only the general’s side of the conversation: he told the governor, who was learning of the imminent test for the first time, that he should be prepared to “invoke martial law come dawn if the thing does more damage than we anticipate.”

Oppenheimer and the rest stepped outside, leaving only the person manning the abort switch. Groves, Teller, Feynman, and Fermi—the Italian navigator himself, who had moved to Los Alamos from Chicago last year—were scattered along with many more men at three of the cardinal points; the general had insisted on dispersal of the team so that if something did go wrong at least some essential personnel might survive.

At 5:29:50—with a mere ten seconds to go—a final warning gong sounded, an Oriental instrument signaling looming American triumph. Oppie took his piece of #10 welder’s glass from his pocket. “Five!” said a male voice over the external loudspeaker. “Four!” Oppie found his lungs paralyzed. “Three!” His heart, though, was pounding hard enough to shake his whole body. “Two!” He held the deep-amber glass up, his blue eyes reflecting back at him as green—“One!” —the same green, he realized with a start, as Jean Tatlock’s.

Light! Fierce. Pure. Blinding.

The cruel brightness, immediately unbearable, kept increasing. Silent light, holy light—not a sound to it yet but an intensity no one on earth had ever before experienced. For the first time, humans were doing what only the stars themselves had previously wrought, converting matter directly into energy, Einstein’s E=mc² graduating from mere textbook formula into a devastating weapon.

The dome of blinding light grew and grew; Oppie estimated it was now a mile, now two, now three in diameter. And the color, which had started as pure white, then yellow, then a cacophony of hues, had now settled on an actinic purple, a radiant bruise on the firmament.

And then the light rose up—by God, yes, on a giant stalk, the hemisphere being pushed higher and higher, hell meeting heaven. Oppie hadn’t expected that; no one had. It looked for all the world like an incandescent parasol, a mushroom of flame, miles tall.

And, at last, a thunderous crack! as the sound of the explosion hit them. Hands flew up to ears; eyes that had endured the brightness behind opaque glass winced at the volume. Oppie had done the math in advance: he knew it was therefore now twenty-five seconds after the timer had reached zero, but it felt like many minutes.

Next came the blast’s scalding wind. Robert, incredibly, managed to keep erect; the more substantial Kisty, off to one side, was blown over but soon picked himself up and pushed against the gale to make it over to his boss. “You owe me ten bucks!” he shouted, his balding head split by a wide grin as he slapped Oppie on the back.

Oppie pulled out his wallet only to find it empty. “You’ll have to wait!” he shouted.

Someone else was making his way over to him: Ken Bainbridge, the test-site director, with a serpent-like mouth. “Now we’re all sons of bitches!” he yelled over the roar.

Yes, thought Oppie. We surely are. We’ve changed the world, won the war, and thrown down a marker in time: the whole, vast past was prologue; everything henceforth is part of a new epoch, a new period, a new era. The previous eras had been named for the ever-more-sophisticated animal life that had emerged in them: Paleozoic, Mesozoic, Cenozoic. But this new one had as its hallmark not unbridled biology but harnessed devastation.

The crowd around him was jubilant. Everyone was going to want to speak to him, he knew: to shake his hand, to offer congratulations, to share their views. But he needed a moment of peace as the weapon to end all war continued to assault the very sky in front of him. Oppie stepped away, walking sideways, keeping his eyes, no longer requiring the protective glass, on the great bulbous apparition.

Now …

Such a devilish thing! There were still afterimages, true, but there was also, superimposed in Oppie’s mind, a conjured city centered at ground zero, ceasing to be, incinerating into nothingness.

Now I am …

Robert’s primary education, at Felix Adler’s Ethical Culture School—the abstract made concrete, that school of philosophy given brownstone-and-mortar reality—had elevated his thinking, and Hindu mysticism had given him insights few of his Western contemporaries shared.

Now I am become Death …

Oppie had studied Sanskrit under the great Arthur Ryder so he could read the Bhagavad Gita in the original, and he thought as easily in that Hindu tongue as he did in English … or French, or German, or Dutch. He suspected that whatever language he used shaped his thoughts: German, with its compound nouns, was appropriate to the unification of physical forces; English, with its heavy freight of adjectives, was about one thing modifying another.

But Hindi—the Gita—was about deep connections, and its words, those terrible, portentous words, erupted in his consciousness as the towering maelstrom continued to roil the sky.

Now I am become Death, the destroyer of worlds.