The team assembled to create the atom bomb debated whether the explosion might be so powerful that it would ignite the atmosphere and destroy life on earth.

This is one of the facts about the build-up to, and eventual explosion of, the first nuclear weapon, revealed by eye-witnesses in interviews with the Atomic Heritage Foundation.

Business Insider reports that for years, a team of the world’s greatest scientists, lead by J Robert Oppenheimer, worked to make the bomb a reality.

Codenamed the Manhattan Project, this large-scale research and development program pumped millions of dollars into new research centres like the bomb-building lab at Los Alamos, New Mexico, and the fissionable material production centre at Hanford, Washington.

Ironically, the very conditions that had once impeded technological development became beneficial – lots of wide open unpopulated federal land where dangerous experiments could be conducted in secret, including the detonation of the first nuclear bomb.

When top scientists and military chiefs assembled in the desert near Socorro, New Mexico, to watch the first ever nuclear explosion on July 16, 1945, many were nervous. No one, after all, knew for sure what would happen.

Elsie McMillan recalls her husband, physicist Edwin McMillan’s, mindset before the test:

“We know that there are three possibilities. One, that we will all be blown to bits, if it is more powerful than we expect. If this happens, you and the world will be immediately told. Two, it may be a complete dud. If this happens, you will also be told. Third, it may as we hope be a success. We pray without loss of any lives.

“In this case, there will be a broadcast to the world with a plausible explanation for the noise and the tremendous flash of light which will appear in the sky,” she said in an interview with the nonprofit the Atomic Heritage Foundation (AHF), which has collected many eyewitness accounts of the day.

The bomb was nicknamed ‘Gadget’, took three years to make, and was detonated at a site Oppenheimer had named Trinity, after a poem by 17th century English writer, John Donne.

“There was a countdown by Sam Allison, the first time in my life I ever heard anyone count backwards,” recalled physicist Marvin Wilkening, who watched the explosion from a shelter about 20 miles (32 km) away with top scientists and military chiefs.

“We used welder’s glass in front of our eyes, and covered all our skin. When the countdown ended, it was like being close to an old-fashioned photo flashbulb.”

Brigadier General Thomas F. Farrellwas astonished by how “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. It was that beauty the great poets dream about but describe most poorly and inadequately.”

Others were horrified by its potential for destruction.

“It was the most shocking, enormous explosion that I had ever seen. I was about twenty miles (32km) away from the site. We were supposed to keep our eyes closed for the first ten seconds because of ultraviolet radiations,” recalled William Spindel, a member of the Special Engineer Detachment.

“I estimated that at twenty miles (32 km) away, the explosion traveling at the speed of sound would take about a minute to reach me. It was the most intimidating minute I have ever spent.

“Seeing the terrible ball, growing and growing, enormous colours. What kind of blast could it be when it finally got to me? Fortunately, it wasn’t that great because I’m still here.”

Roger Rasmussen, another member of the Special Engineer Detachment said this:

“We stood up and looked into this black abyss ahead of us. There was this beautiful colour of the bomb, gorgeous. The colours were roving in and out of our visual range of course. The neutrons and gamma rays and all that went by with the first flash while we were down. There we stood, gawking at this.”

When asked to describe his reaction to the first explosion, Oppenheimer quoted a verse from the Baghavad Gita:

“Now I am become Death, the destroyer of worlds.”

A suitably ominous quote for the first-ever nuclear bomb explosion, but not likely to rival Neil Armstrong’s “one small step for [a] man, one giant leap for mankind”.

[source:businessinsider]