For America, World War II ended in a dark mirror image of the way our involvement began. The December 7th, 1941 attack on Pearl Harbor was an unannounced pre-emptive strike by Japan on a military base. America's August 6th, 1945 atomic bombing of Hiroshima, and the subsequent August 9th atomic bombing of Nagasaki, came at the end of an already long war. American bombers had torched many other cities in Japan previously; Hiroshima and Nagasaki were largely untouched by conventional bombs, instead slotted as targets for the first, and to date only, uses of nuclear weapons in anger.
Last year, Popular Science looked into our archives to see how we covered the bombings in 1945. On the shelves in August of that year, our issue contained an argument that bombardment with poison gas, a weapon of mass destruction, was needed to end the war. The September issue, published after the world knew of the unique bombs dropped on Japan, includes a statement by the editors entitled “Annihilation Bomb - Friend or Foe?” that notes just how unprecedented this explosion was:
Nine million pounds of ammonium nitrate exploded near Oppau, Germany, in 1921, causing serious damage four miles away. That was the greatest weight of manmade material ever known to have exploded at one time. The exploding charge in the annihilation bomb weighed only a few pounds, but its effects were so devastating that it almost wiped out a city spread over nearly seven square miles. Even so, Oppau and Hiroshima are scarcely comparable. In the kind of explosion that occurred at Oppau, materials such as steel have been torn into fragments, twisted and strewn over the countryside; at Hiroshima, steel appears to have been turned into gases.
The statement ended on an optimistic note, looking to the coming scientific age and the long task of turning the energy harnessed in the atom to peaceful purposes.
In “How Physics Drove the Design of the Atomic Bombs Dropped,” Smithsonian Magazine examines the science behind the first two atomic bombs, Little Boy and Fat Man, and the attempted but unsuccessful “Thin Man” design:
Oppenheimer at first placed his faith in a design codenamed Thin Man, a long, skinny gun-type bomb. It would fire a plug of radioactive material at a target made of the same stuff, so that the combined forces of compression and increased mass triggered the chain reaction that would lead to a fission explosion. As a hedge, another team was investigating an implosion bomb, which would compress a subcritical mass of material in a core surrounded by explosives. When the charges went off, the ball of material would get squeezed from the size of a grapefruit to that of a tennis ball, reaching critical mass and detonating the bomb.
To commemorate the occasion, The New Yorker put its August 1946 story “Hiroshima” online. Reporter John Hersey recounts six narratives of the day from people present in the city for the bombing. The full piece is worth reading in full. All of it is haunting; here is the opening of one narrative:
The Reverend Mr. Tanimoto got up at five o'clock that morning. He was alone in the parsonage, because for some time his wife had been commuting with their year-old baby to spend nights with a friend in Ushida, a suburb to the north. Of all the important cities of Japan, only two, Kyoto and Hiroshima, had not been visited in strength by B-san, or Mr. B, as the Japanese, with a mixture of respect and unhappy familiarity, called the B-29; and Mr. Tanimoto, like all his neighbors and friends, was almost sick with anxiety. He had heard uncomfortably detailed accounts of mass raids on Kure, Iwakuni, Tokuyama, and other nearby towns; he was sure Hiroshima's turn would come soon. He had slept badly the night before, because there had been several air-raid warnings. Hiroshima had been getting such warnings almost every night for weeks, for at that time the B-29s were using Lake Biwa, northeast of Hiroshima, as a rendez-vous point, and no matter what city the Americans planned to hit, the Super-fortresses streamed in over the coast near Hiroshima. The frequency of the warnings and the continued abstinence of Mr. B with respect to Hiroshima had made its citizens jittery; a rumor was going around that the Americans were saving something special for the city.
The Bulletin of the Atomic Scientists, perhaps best known for maintaining a Doomsday Clock for humanity, this week published the story of the Nagasaki mission, as told by Frederick L. Ashworth, the operations officer in command of the Fat Man bomb on board the plane. Ashworth recounts the harrowing, mishap-filled flight:
“Hey, Commander, Ashworth, Dick.” Barnes called him first by rank, then last name, then first name, with increasing terror. “Hey, we got something wrong here. We got a red light going off like the bomb is going to explode right now. Armed, it's armed. Fully armed, look at this. Can you take a look, what is going on with this?” A red light that had been blinking steadily suddenly sped up, flashing a dire warning. Ashworth said he shook himself awake. “Are you sure? Oh my God.” He saw the red light. “There is something … do you have the blueprints? This bomb can pre-detonate if we drop below a predetermined level. What's our altitude? Where are the blueprints?” Barnes and Ashworth unrolled the blueprints and started checking. They took the casing off the bomb, and scrutinized the switches. After 10 tense minutes, they saw the problem. Two switches had been reversed, a mistake in the arming process. Barnes flipped the two tiny switches into their proper positions and the red light stopped blinking.
Japan, surrendered and rebuilt after World War II, became a staunch American ally. To honor America's bicentennial, Japanese bonsai master Masaru Yamaki donated a bonsai pine to Washington's National Arboretum in 1976. The 390-year-old tree, it turns out, was less than two miles from Ground Zero in Hiroshima, and survived the blast by being up against a wall. The Washington Post has the full story.
The Cold War and the prospect of global nuclear annihilation dominated thought in the decades since the blast. No country has used an atomic weapon in anger since the war, though their spread still remains a paramount concern. Yesterday, President Obama gave a speech at American University to make the case for a deal, negotiated with Iran, designed to curtail the development of an Iranian nuclear weapon. No country since the United States has used a nuclear weapon in war.
There have been a bunch of nuclear tests since then, though. Here's a video timeline of every nuclear test since the first, at the Trinity Site in New Mexico in July 1945:
In “Seven decades after Hiroshima, is there still a nuclear taboo?, William Burr and Jeffrey Kimball look at the long history of the weapons' non-use. They note that, while the United States hasn't used a nuclear weapon again, policy makers and military planners sometimes still allude to the arsenal and threaten its use.
The likelihood of deliberate nuclear use by the United States faded as the nuclear taboo became central to the worldview of policymakers, but nuclear threats remained in the playbook of top officials. During the 1991 Persian Gulf War, senior members in President George H. W. Bush's administration declared that nuclear weapons were “taboo” and “unusable” and that employing them would cause Washington to “lose the moral high ground,” among other considerations. Nevertheless, other officials floated implicit warnings that could be construed as nuclear threats. Chairman of the Joint Chiefs of Staff Colin Powell, for example, declared that if the Iraqis used chemical or biological weapons, the American people would require “vengeance,” and said that they “have the means to extract it.”
American public opinion is also moving away from support for the past bombings. From Pew:
In 1945, a Gallup poll immediately after the bombing found that 85% of Americans approved of using the new atomic weapon on Japanese cities. In 1991, according to a Detroit Free Press survey conducted in both Japan and the U.S., 63% of Americans said the atomic bomb attacks on Japan were a justified means of ending the war, while only 29% thought the action was unjustified. At the same time, only 29% of Japanese said the bombing was justified, while 64% thought it was unwarranted. But a 2015 Pew Research Center survey finds that the share of Americans who believe the use of nuclear weapons was justified is now 56%, with 34% saying it was not. In Japan, only 14% say the bombing was justified, versus 79% who say it was not.
Reflections on the bombing extend not just to policy makers and the general public, but to craft brewers and artists. For the 70th anniversary of Hiroshima, the United Kingdom's Hardknott Brewery made a “Nuclear Sunset” beer. Inspired by a Japanese wheat beer and made as much in connection to the nuclear energy industry as the nuclear weapons, perhaps its orange peel, orange juice coriander and nutmeg notes add a moment of peace to contemplation about nuclear power.
My favorite meditation on the topic instead comes in infographic form. Made by Matthew Lucas, the three infographics are shaped to match a blast, a targeting reticle, and an atom. Built from a timeline of bomb development, a list of atomic casualties, and bomb development sites, that capture the scale of the effort that went into unleashing such a weapon on the world, and the scale of the harm done.