History: At 08:15:02 on August 6th, 1945, Bob Lewis, co-pilot on the US B-29 bomber Enola Gay, scribbled quickly into the plane's log: "There will be a short intermission while we bomb our target". Exactly 15 seconds later the world changed forever. The first nuclear weapon - codenamed Little Boy - was dropped into the freezing skies above Hiroshima in Japan, writes Richard Aldous
Forty-five seconds after that, the bomb detonated with immediate cataclysmic effect. In the first billionth of a second, the temperature reached 60 million degrees. A 1,000mph (160km/hr) wind instantaneously spread the heat across the city in a blinding flash of light. Then came the fallout of radiation. Of a population of 300,000, barely a third survived.
Hiroshima was bombed 60 years ago today. It continues to hold a tight grip on our imaginations. Bombs have become a detestable part of contemporary life, recently claiming Irish victims in London and Turkey. Suicide bombers, shoe bombers, cluster bombs, missiles so sophisticated they can follow street directions: this is the modern world we inhabit. Yet for all that, the events of Hiroshima retain their power to overwhelm and disturb. For this was not just a bomb, it was The Bomb. Within a generation it would have the capacity to annihilate humankind many times over. Hiroshima is the stuff of nightmares because, as Enola Gay's tail gunner, Bob Caron, said afterwards, it gave us "a peep into hell".
The story of Hiroshima is told in these two new books published to coincide with the anniversary. Stephen Walker focuses on the critical three weeks between the first atomic test explosion in New Mexico and the dropping of the bomb. Shockwave is a stunning book, among the most immediate and thrilling works of history I have ever read. To read the account of the flight to Hiroshima is almost to be on the Enola Gay with Little Boy juddering ominously in the bomb bay. Walker is a filmmaker, and he brings a director's eye for pace, character and colour to this book so that the reading experience is almost a visual one.
Take, for example, the moment when the bomb is armed, less than 90 minutes from the target. We find Morris Jeppson, the weapon test officer, alone in the bomb bay holding his red five-pin arming plugs, fleetingly wondering whether or not he should toss them away and let the bomb fall as a dud. Of course, he doesn't, but, as so often in this book, Walker conveys the drama of the moment as an individual weighs in the balance the strictures of his own conscience and his duty to the flag. "He was the last man to touch the bomb," writes Walker dramatically.
As we approach the moment of detonation, Walker escalates the minute-by-minute tension by skilfully juxtaposing what's going on in the B-29 bomber with the lives of unsuspecting characters on the ground below. When the bomb finally hits, he allows the grim facts to speak for themselves. "In that first half hour after the bomb fell, Hiroshima's identity as a city effectively ceased to exist," he concludes. "The bomb overwhelmed everything and everyone in a single devastating, unparalleled blow."
Three hours later the crew of the Enola Gay touched down on Tinian in the Pacific to a hero's welcome and party for all the base ("Jitterbug contest, food galore and free beer", announced the poster). Paul Tibbets, captain of the Enola Gay, said afterwards that "Nobody in my airplane ever had the least emotional problem or lost a night's sleep over the Hiroshima mission".
Others were less convinced. "There was nothing but death in that cloud," the assistant engineer, Robert Shumard, remembered. "All those Japanese souls ascending to Heaven." It is a comment that suggests more than one restless night.
Shockwave magnificently captures the chilling drama of those 21 days. Those who read it and want to set the story in its broader context will be well-served by Before the Fall-Out. Diana Preston, who worked for the UK Atomic Energy Authority, takes the story back to Marie Curie at the turn of the century, following the twists and turns as the power of the split atom moved inexorably from scientific inquiry to awesome weapon. "The destructive flash that seared Hiroshima into history," she writes, "was the culmination of 50 years of scientific creativity and . . . political and military turmoil."
Preston's is as much the story of modern physics as politics, and her book comes alive when dealing with the brilliant, highly strung scientists. She neatly evokes the freezing Birmingham lab where two refugees, Otto Frisch and Rudolph Peierls, worked out that a chain reaction could last long enough to cause a catastrophic explosion. The result was the famous 1940 Frisch-Peierls memorandum on the construction of a superbomb that "will kill everybody within a strip estimated to be several miles long". The memorandum started its own chain reaction from Birmingham to London to Washington, leading directly to the Manhattan Project and that first atomic test explosion (to the strains through a tannoy, Walker tells us, of Tchaikovsky's Serenade for Strings).
It is details such as this last one that in the end will draw most readers to Stephen Walker's Shockwave. He captures the sense of what it was like to be there that day, August 6th, 1945. Bob Lewis, the co-pilot, summed it up when he returned to his log after that short intermission. "My God," he wrote, "what have we done?"
Richard Aldous teaches international history at UCD. His Macmillan, Eisenhower and the Cold War was published in May by Four Courts Press
Shockwave: The Countdown to Hiroshima. By Stephen Walker, John Murray, 352pp. £20
Before the Fall-Out: The Human Chain Reaction from Marie Curie to Hiroshima. By Diana Preston, Doubleday, 438pp. £20