50 years ago occurred the greatest flexing of nuclear might ever conducted by the United States. 'Castle Bravo' was the largest of the highly photogenic 'Castle' series of atomic tests conducted in the Bikini Atoll. It was intended to be a 6 megaton blast but apparent differences in the actual versus modeled behavior of the forces unleashed by that design brought the energy of that blast to 15 megatons, the largest of any US test. It would not be surpassed until the detonation of a Soviet behemoth whose 50 megatons seared the arctic island of Novaya Zemlya on October 30 1961.
To me it was something beyond an atomic test, it was a kind of miracle in the middle of the ocean, weapons testing elevated to grand performance art. It was the human race defiantly shaking its fist on a massive scale, the power of Man tapping the energy of the all its Gods from the ancient nature spirits of pagan times to the later apocalyptic Christian tradition. It was a demonstration of what scientific knowledge and technology could do, a terrible searing sword slashing across the heavens. Such audacious acts were the product of the mid 20th century, a time of grand dreams and the affluence to pursue some of them, a time when we dared to dream big and were not afraid to act on some of those schemes. A decade later such bravado would be channeled to bring Humanity to space and in another decade to the Moon itself. The radio convulsions from these tests were the largest and furthest spread signals ever created by Humanity and now are spreading across the universe. Indeed if there was one thing I would make sure an alien visitor saw of the works of Man, among the great accomplishments and works of art I would play a video of the Castle Bravo test. That would tell them a lot about us, perhaps too much.
This test took place at the first light of dawn, March 1 1954. The initial flash lit up the surrounding cumulus clouds, dimming as the spherical fireball grew like an expanding star, momentarily darkened revealing brilliant round spots scattered across it. The expanding hemisphere of energy brightened from the top until it was too bright to dare behold. Cloud formations were lit from hundreds of miles away, the intervening atmosphere reddening the light to the pure crimsons of sunrises. Clouds near the growing fireball evaporated and retreated as they made way for this astonishing event in their midst. The perfectly circular shock wave spreading from its base tore the surface of the sea to frothy mist, shining like snow in the pitiless dazzling radiance of the still growing hemisphere of light. The shock wave grew as a sharply defined widening circle. After engulfing 5 km of the lower atmosphere the interior convection currents of the great dome of incandescence began to assert themselves, rising and leaving behind shapeless 'fire falls' plunging into the hissing ocean as if being poured from the steel mills of the gods. The fireball transformed into the head of the developing mushroom cloud, slowly rolling inwardly upon itself at the bottom to rise again through the center atop a column of superheated air. The ocean below convulsed to fill the new two kilometer (mile and a half) wide depression beneath it.
To embellish a bit of the oldest story in the world, the 'Epic of Gilgamesh':
'With the first light of dawn the gods of the abyss rose up; the seven judges of hell raised their torches, lighting the land with their livid flame. A stupor of despair went up to heaven when the god of the storm turned darkness to daylight, when he smashed the land like a cup. The tempest raged, gathering fury as it went, it poured over the people like the tides of battle; a man could not see his brother nor the people be seen from heaven. Even the gods were terrified, they fled to the highest heaven, they crouched against the walls, cowering like curs. The very Queen of Heaven cried out like a woman in travail.'
The vast fiery mass rose as a dome of golden searing heat, steadily bringing forth cooler billows like those of great thunderheads, reddening as they rolled out from the apex and down the sides to expose yet more rising sunlike brilliance. The brilliant miles wide mushroom crown continued its toroidal circulation up it's center drawing up from below a great column, the 'mushroom' quickly towering well over the clouds. The interior glow steadily shone through greater layers of all three states of water as steam, upthrown spray, and even layers of ice cloud were carried to extreme altitudes.
Layer after layer of surrounding moist air brought forth a series of flattened stacked rings of crowning clouds materializing and growing like heavenly adornments, stretching upwards as if recoiling from the blazing apparition in their midst. The still incandescent rising cloud pushed its way higher than the tallest mountain 50 seconds after detonation. As it did so layer upon layer of transluscent gossamer topping appeared, was pushed up and distorted. Almost jellyfish like in its smoothly organic contours, the last glowing light of the power of the stars released on Earth shone through these ice cap clouds in a diffused ethereal radiance.
After a minute had passed the cloud climbed to 50 thousand feet, by three minutes 100,000 feet. (about 19 miles, or 30 km) The base of the mushroom actually climbed above 50 thousand feet, with a 100 km (62 mile) wide crown stretching out to soon settle downwind and rain death upon the world below. Although the weather was becoming unfavorable for the desired dispersal of the plume to 'empty' stretches of the ocean, the test was ordered to proceed anyway. The unexpected power of the blast marooned the firing crew in their sealed bunkers for awhile, alarmed by the water pressure surge causing pipes to burst and making them briefly worry their bunker had been submerged! Observation ships were covered with 2 inches of highly radioactive dust., their crews ordered to lower decks to reduce exposure. Sadly, modern safety measures were generally not provided to servicemen in subsequent cleanup efforts, with later devastating health consequences. Over vast parts of the Pacific, Marshallese islanders were exposed, over a hundred critically. The Japanese fishing vessel '5th Lucky Dragon' was heavily dusted with fallout from the wandering blast plume, all crewmen severely exposed and one dying of the effects of exposure.
Atomic weapons were developed to do with one aircraft (or missile) what a thousand planes were required to do as the destruction of entire cities became part of the conduct of the Second World War. They were initially treated as merely a high yield explosive, despite initial indications of the terrible effects of radiation from atomic blasts. Castle Bravo marked our mass realization of the terrible price we paid for the creation of these weapons, the hidden clause of our contract with the Devil. The very images and knowledge of what such power could inflict on environments and to people has served as a warning which many people have in their own ways acted upon. A full scale nuclear war involving thousands of detonations between the superpowers has become quite unlikely thanks to attention paid to its consequences, although regional conflicts and terrorist actions seem ominously likely to sear themselves into the collective psyche in the uncertain times ahead. Once something is invented, it is almost never uninvented and knowledge of this power can only spread, however gradually. Whatever the ultimate consequences, the fact that we have delved into the mysteries of existence to our ends gives us not only more power but more responsibility than we have ever had to contemplate.
Much information on atomic tests can be found in the Nuclear Weapons Archive , from which some of the above facts are referenced.