Pacific: The Ocean of the Future. Simon Winchester

the coming days. The Times triple-decker front-page headline on the morning after intimated, at least among the editors, an early degree of sobriety, verging on disappointment. “Blast Force Seems Less Than Expected,” it read, and the lead paragraph’s obligatory description of the bomb’s initial dazzling flash as “ten times brighter than the sun” was followed by a cautionary “but,” and by the news that of the seventy-three ships moored inside the atoll, only two had actually been sunk. The paper may have been a little hasty, because actually five went down: two old American destroyers, two transport ships, and, eventually, the graceful Japanese cruiser Sakawa, which had been seriously damaged and which foundered as she was being towed from her anchorage. She nearly dragged the towing tug down with her, though panicking crewmen cut the towline with acetylene torches in the nick of time.

      Aside from being the first atomic bomb detonation ever seen publicly, the Able shot is now probably best remembered for what it failed to do—and because some of the failures were positive, and confirmed what Admiral Blandy had reassured everyone days beforehand: “The bomb will not start a chain-reaction in the water converting it all to gas and letting the ships on all the oceans drop down to the bottom. It will not blow out the bottom of the sea and let all the water run down the hole. It will not destroy gravity.” It didn’t set fire to any of Bikini’s palm trees, either.

But it also didn’t do what was hoped for. It didn’t seem to stir much agitation among the immense fleet arrayed around the drop zone. It damaged generally only rather small ships that were very close to the explosion’s center. It failed to sink the USS Nevada; it failed to sink the enormous Japanese battleship Nagato—a fate that many had hoped for, since Nagato had been Admiral Yamamoto’s flagship during the raid on Pearl Harbor, and her destruction would have been rich in retributive symmetry. It also failed to sink the former German pocket battleship Prinz Eugen, which was at the time a commissioned ship of the U.S. Navy, having been claimed as a war prize and been brought all the way to Bikini from Wilhelmshaven by a German American crew.6

      The bomb also didn’t do as much damage to the animals that had been posted onto some of the ships as stand-ins for crewmen. There were goats in gun turrets, rats at the radar screens, pigs on the poop decks, mice by the mainmast, and rodents by the score just about everywhere. Three quarters of them survived, for a while, some of the goats chewing away unconcernedly while all hell was breaking out about them. Two celebrated survivors, Pig 311 and Goat 315, remained so healthy for so long that they were brought to Washington, DC, and put on display at the zoo.

      The second reason for the Able shot’s historic importance is more technical, and has whispers of the macabre. For the plutonium in the core of the weapon, which had been manufactured in August of the previous year, had already been involved in no fewer than two fatal accidents at the nuclear program headquarters at Los Alamos.

      The components of the core, when kept apart from each other, were not especially dangerous—but when pressed together, and under certain circumstances, they could go “prompt critical,” as the phrase has it, and release sudden immense amounts of radiation. This is what had happened to this particular core, twice. First, on August 21, a physicist named Harry Daghlian dropped a tungsten carbide brick onto the core, causing it to go critical and douse Daghlian with enough radiation to kill him four weeks later.

      The more notorious second incident took place in 1946, the following May. A flamboyant Los Alamos experimenter named Louis Slotin was carefully turning the blade of a screwdriver to lever the two nickel-plated sphere halves apart, and then move them closer to each other to measure the increasing radiation—“tickling the dragon’s tail,” as it was called. During this delicate process something startled him—in the feature film made of the event, it was the breaking of a dropped teacup—and he jerked the screwdriver, causing the hemispheres suddenly to close on each other. There was a blinding blue flash of Cherenkov radiation, and all the Geiger counters in the room went promptly off scale. Slotin stood up and shoved the top hemisphere onto the floor, ending the criticality and, with it, the radiation burst. But in doing so, he received a formidable dose of neutron and gamma radiation on his hand, and he calculated within hours that he was soon going to die. He was exactly right; and he did so, in intense pain, nine days later.

      From then on, as a consequence of these two deaths, the twin half spheres of plutonium, with their shields of nickel and beryllium, became collectively known as the Demon Core. It was this very core that would become the operational heart of the Able shot. One could imagine the physicists just wanting to use it up, to explode it and take it out of their tiny inventory of plutonium bomb charges. But given its sorry history, the superstitious might well say that the use of the Demon Core guaranteed that the Able shot was doomed, either to cause more accidents or to be a failure.

      In the end the only certain “casualty” of the first Crossroads bomb was the captain of the plane that dropped it, who banged his lip when the shock wave struck his departing B-29. What otherwise haunted Able was not disaster, but indeed, a certain sense of failure.

      For it also largely failed to impress. Few of the UN observers sent to monitor the event were captivated. A Soviet professor, Simon Alexandrov, gave a very Russian shrug of his shoulders and, using a locution more modern than he knew, declared the bomb “not so much.” A Brazilian said it was “so-so.” A New York congressman said he felt the heat wave, but agreed with others aboard the observers’ ship that the eighteen-mile distance to the drop zone had somewhat reduced the spectacle. Weathermen said the humid air had also deadened the sound and heat radiation. Newspapers in the United States photographed the mothers of the pilot and bombardier who’d dropped the weapon. These two bespectacled ladies, gathered in La Crosse, Wisconsin, appeared curiously unmoved. Only after the weapon had exploded did they say their boys must surely have enjoyed their adventure.

      It was beginning to look as though the Bikinians had been turfed out of their home for nothing. But then came the second of the Crossroads tests, the Baker shot, on July 25. This was a far greater spectacle—at first a supposed success, in a military and a public relations sense. Yet it was also, in some other ways, a disaster—the first, as it happened, of several.

      Able had been an air-dropped bomb. Baker, which was also designed to measure the effect of atomic weapons on the waiting congregation of capital ships, was by contrast to be exploded underwater. The official explanation for Able’s signal failure to sink as many ships as expected was that most of its damage had been done above the vessels’ waterlines. Baker would, by contrast, do its damage to underwater hulls rather than above-water superstructures. As a ship killer, it should have been more effective.

      Indeed, it was—both effective and spectacular-looking enough to be, for a while, the poster child, quite literally, of the atomic age. The bomb was suspended ninety feet down in the water, inside a concrete container held by steel cables from the underside of an old landing craft. So confident was Admiral Blandy that this shot would be a success that he summoned Juda, the Bikinian leader, over from Rongerik to view it. Blandy didn’t imagine Juda would show up, but when he did, and boarded the navy observation vessel, he told his hosts he was looking forward to the explosion, and he hoped that once it was done with, he would be able to bring his people home. It was the wishful thinking of the truest naïf.

      The weapon was duly exploded at 8:35 a.m. and provided the watchers with a spectacle they would never forget. With a gigantic whoosh, it suddenly created at first a mile-wide glass-bubble sphere of water and steam and condensate and crushed coral and mud that thundered out of the mirror-calm blue of the lagoon, and out of which erupted, at fantastic speed, a perfectly symmetrical hollow column, a mile high, of millions of tons of near-white water and seafloor sand topped by a ragged cloud of spray and coral debris—and which, caught by cameras as it fell slowly back into the lagoon, remains today one of the iconic images of the time. To those enthralled by matters atomic—and many young Americans especially were utterly captivated—it was to be the perfect wall poster, to be set alongside a pouting Brigitte Bardot and Marilyn Monroe laughing at her billowing dress. The mushroom cloud had already become something of a cartoonable cliché: that there was none produced after the Baker shot—subsea detonations produce much more of a crown-shaped,