July 16, 1945
The Trinity Test had been firmly established for 4:00 a.m. Monday, July 16, but an intense rainstorm caused the test to be postponed for approximately one and a half hours. the countdown began at 5:10 and at 5:29:45 a.m. the bomb was detonated.
"My first impression of the explosion was the very intense flash of light, and a sensation of heat on the parts of my body that were exposed. although I did not look directly towards the object, I had the impression that suddenly the countryside became brighter than full daylight. I subsequently looked in the direction of the explosion through the dark glass and could see something that looked like a conglomeration of flames that promptly started rising. after a few seconds the rising flames lost their brightness and appeared as a huge pillar of smoke with an expanded head like a gigantic mushroom that rose rapidly beyond the clouds, probably to a height on the order of 30,000 feet. after reaching full height, the smoke stayed stationary for a while before the wind started dispersing it." – Enrico Fermi
"It looked like a giant magnesium flare which kept on for what seemed a whole minute but was actually one or two seconds. the white ball grew and after a few seconds became clouded with dust whipped up by the explosion from the ground and rose and left behind a black trail of dust particles. the rise, though it seemed slow, took place at a velocity of 120 meters per second. after more than half a minute, the flame died down and the ball, which had •been a brilliant white, became a dull purple. it continued to rise and spread at the same time and finally broke through and rose above the clouds which were 15,000 feet above the ground. it could be distinguished from the clouds by its color and could be followed to a height of 40,000 feet above the ground." – Hans Bethe
"After I threw my last switch I ran out to take a look and realized the shock wave hadn't arrived yet. I ducked behind an earth mound. Even then I had the impression that this thing had gone really big. It was just terrific." – Joe McKibben, the man who detonated the bomb
"The shot was truly awe-inspiring. most experiences in life can be comprehended by prior experiences but the atom bomb did not fit into any preconception possessed by anybody. the most startling feature was the intense light." – Norris Bradbury
"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 countryside was lighted by a searing light with the intensity many 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. seconds after the explosion came, first, the air blast pressing hard against the people, to be followed almost immediately by the strong, sustained awesome roar which warned of doomsday and made us feel we puny things were blasphemous to dare tamper with forces heretofore reserved for the almighty." – Brigadier General Farrell, Grove's Deputy
"The long-hairs have let it get away from them." – observer at site
"It was like the grand finale of a mighty symphony of the elements. fascinating and terrifying, uplifting and crushing, ominous, devastating, full of great promise and great foreboding. - William L. Laurence, New York Times
"The grand, indeed almost cataclysmic proportion of the explosion produced a kind of solemnity in everyone's behavior immediately afterwards. there was a restrained applause, but more a hushed murmuring bordering on reverence as the event commented upon." – Ernest O. Lawrence
"The tension in the room let up and all started congratulating each other. all the pent-up emotions were released in those few minutes and all seemed to sense immediately that the explosion had far exceeded the most optimistic expectations hopes of the expectations and wildest scientists." – Major General Leslie R. Groves
"Then it came. the blinding light like no other light one had ever seen. the trees illuminated, leaping out. the mountains flashing into life. later, the long slow rumble. something had happened, all right, for good or ill. – observer from Campaña Hill, 20 miles away
"It was not only that we had achieved success with the bomb, but that everyone--scientists, military officers, and engineers - realized we had been personal participants and eyewitnesses to a major milestone in the world's history. – Major General Leslie R. Groves
"Operated on this morning. diagnosis is not yet complete but results seem satisfactory and already exceed expectations. Local press release necessary as interest extends a great distance. Dr. Groves pleased. He returns tomorrow. I will keep you posted." – 1st coded message about Trinity Test to Secretary of War Stimson at Potsdam
"Doctor has just returned most enthusiastic and confident that the Little Boy is as husky as his big brother. The light in his eyes discernible from here to highold and I could hear his screams from here to my farm. – a 2nd coded message about Trinity Test to Secretary of War Stimson at Potsdam
"I am become death, the destroyer of worlds. – J. Robert Oppenheimer repeating an ancient Hindu quotation
Three weeks after the trinity test, on August 6, 1945, the first combat atomic bomb-- a uranium-based device-was dropped on Hiroshima, Japan with devastating effect. sixty percent of the city was destroyed, were 28,000 civilians killed, 37,000 wounded, and 13,000 declared missing, far exceeding the expectations of the American forces.
On August 9, a plutonium-based bomb similar to that tested at Trinity site was dropped on Nagasaki, Japan. its blast completely destroyed an area one mile in diameter and caused almost 75,000 casualties.
On August 14, the Japanese surrendered and World War II came to an end.