July 16, 1945: Trinity Blast Opens Atomic Age

[Oracle]

1945: The first atomic bomb is tested successfully at the Alamogordo Bombing and Gunnery Range in a remote section of desert near Los Alamos, New Mexico. The instant the bomb detonated at 5:30 a.m. that Monday, the atomic age was born, and the world changed forever.

The Trinity test, as it was known, was the culmination of the American effort to win the race against Germany (and, ultimately, the Soviet Union) in building an atomic bomb. A mere three weeks after the test, the United States used atomic bombs to destroy the Japanese cities of Hiroshima and Nagasaki.

But prior to the 16th, none of those involved in the project knew if they had built a devastating new weapon or a spectacular dud.

With gallows humor, the Los Alamos physicists got up a betting pool on the possible yield of the bomb. Estimates ranged from zero to as high as 45,000 tons of TNT. Enrico Fermi, who won the Nobel Prize for Physics in 1938 for his work on nuclear fission, offered side odds on the bomb destroying all life on the planet.

J. Robert Oppenheimer, scientific director of the Manhattan Project, was under no illusions about what he and his fellow physicists had wrought. The effects of the blast, the equivalent of 20,000 tons of TNT, moved the intellectual Oppenheimer to quote from the Bhagavad Gita: "If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one. Now I am become Death, destroyer of worlds."

More prosaically, Dr. Kenneth Bainbridge, site director of the Trinity test, said: "Now we are all sons-of-bitches."

The scientists and military men who were at the Trinity site when the detonation occurred were staggered by what they saw. T. F. Farrell, a brigadier general on the staff of Major Gen. Leslie Groves, the Manhattan Project's military commander, wrote:

The effects could well be called unprecedented, magnificent, beautiful, stupendous and terrifying. No man-made phenomenon of such tremendous power had ever occurred before. The lighting effects beggared description. The whole country was lighted by a searing light with the intensity many times that of the midday sun. It was golden, purple, violet, gray and blue. It lighted every peak, crevasse and ridge of the nearby mountain range with a clarity and beauty that cannot be described but must be seen to be imagined.

The blast, which sent a mushroom cloud boiling 38,000 feet into the sky, was both visible and audible for hundreds of miles around. The heat generated at the blast point was described as being 10,000 times hotter than the surface of the sun. Even at 10 miles removed from ground zero, witnesses said the resulting heat wave was like standing directly in front of a roaring fireplace.

While Oppenheimer said he never regretted helping develop the bomb, he did have second thoughts about the way the United States used it against Japan. Lamont Lansing's book, Day of Trinity, quotes Oppenheimer, then near the end of his life:

As for how we used it, I understand why it happened and appreciate with what nobility those men with whom I'd worked made their decision. But I do not have the feeling that it was done right. The ultimatum to Japan was full of pious platitudes"¦. Our government should have acted with more foresight and clarity in telling the world and Japan what the bomb meant.

Wired

 

[W.G.Ewald]

J. Robert Oppenheimer, scientific director of the Manhattan Project, was under no illusions about what he and his fellow physicists had wrought.

Manhattan Project - Wikipedia, the free encyclopedia

The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army Corps of Engineers. The Army component of the project was designated the Manhattan District; "Manhattan" gradually superseded the official codename, "Development of Substitute Materials", for the entire project. Along the way, the Manhattan Project absorbed its earlier British counterpart, Tube Alloys.

The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion (roughly equivalent to $25.8 billion as of 2012[1]). Over 90% of the cost was for building factories and producing the fissionable materials, with less than 10% for development and production of the weapons. Research and production took place at more than 30 sites, some secret, across the United States, the United Kingdom and Canada. Two types of atomic bomb were developed during the war. A relatively simple gun-type fission weapon was made using uranium-235, an isotope that makes up only 0.7 percent of natural uranium. Since it is chemically identical to the main isotope, uranium-238, and has almost the same mass, it proved difficult to separate. Three methods were employed for uranium enrichment: electromagnetic, gaseous and thermal. Most of this work was performed at Oak Ridge, Tennessee.

In parallel with the work on uranium was an effort to produce plutonium. Reactors were constructed at Hanford, Washington, in which uranium was irradiated and transmuted into plutonium. The plutonium was then chemically separated from the uranium. The gun-type design proved impractical to use with plutonium so a more complex implosion-type weapon was developed in a concerted design and construction effort at the project's weapons research and design laboratory in Los Alamos, New Mexico. The first nuclear device ever detonated was an implosion-type bomb at the Trinity test, conducted at New Mexico's Alamogordo Bombing and Gunnery Range on 16 July 1945. Little Boy, a gun-type weapon, and the implosion-type Fat Man were used in the atomic bombings of Hiroshima and Nagasaki, respectively.