Military

75 years ago, the Trinity atomic bomb test changed the world forever

75 years ago, the Trinity atom...
Trinity milliseconds after the explosion
Trinity milliseconds after the explosion
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The Trinity Test was the first detonation of an atomic weapon
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The Trinity Test was the first detonation of an atomic weapon
The Gadget assembled
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The Gadget assembled
Los Alamos during the Manhattan project
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Los Alamos during the Manhattan project
Trinity base camp
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Trinity base camp
Trinity milliseconds after the explosion
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Trinity milliseconds after the explosion
The Trinity shot tower
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The Trinity shot tower
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July 16 marks the 75th anniversary of the first detonation of an atomic bomb. Now famous as the Trinity Test, the giant explosion was the culmination of the ultra-secret Manhattan project and would within weeks lead to the end of the Second World War and usher in the Atomic Age.

On July 16, 1945, at 5:29 AM, the predawn darkness on what was then the United States Army Air Force (USAAF) Alamogordo Bombing and Gunnery Range in the Jornada del Muerto desert about 35 miles southeast of Socorro, New Mexico, was suddenly lit up with the light of a thousand suns. As a collection of the world's leading scientists looked on from a safe distance, an ordinary-looking steel tower vanished in a fraction of a second as the world's first plutonium bomb instantaneously converted matter into energy.

That day was the sharp end of three years of hard work carried out in a boomtown that is now the Los Alamos National Laboratory. Back then it had a population of 6,000 living in a collection of mud streets and hastily erected wooden buildings with just five bathtubs, and it was the center of the Manhattan project – the highly secret Allied effort to build the atomic bomb.

Los Alamos during the Manhattan project
Los Alamos during the Manhattan project

It began life originally as a British weapons project, but with the British Isles under constant German bomber attack, and every factory turned over to cranking out conventional weapons, it was decided to pool Britain's efforts with America's, resulting in the Manhattan project coming to life in June 1942.

Today, weapon development is highly evolutionary, building on the work that has been done by others going back decades, if not centuries, but the Manhattan project was about as close to starting from scratch as one can imagine. When the project began under the leadership of Brigadier General Leslie R. Groves and physicist J. Robert Oppenheimer, they were working almost entirely on theoretical work and a few laboratory experiments. To give an idea of how far they had to go, in those days, there was only enough plutonium in the world to cover the head of a pin – nowhere near enough to build a bomb, even if they were sure it could be done.

Fast forward to 1945 and the physicists and engineers at Los Alamos had produced two prototype nuclear devices. One was a simple design that worked by an explosive charge in a tube that slammed two plugs of uranium-235 together, resulting in a critical mass that set off a chain reaction as the uranium atoms burst apart, spewing out neutrons that split more uranium atoms in a cascade of destruction.

Trinity base camp
Trinity base camp

The uranium bomb was so simple that the scientists didn't feel it necessary to test it, but the second bomb, called the Gadget, was much more sophisticated. The Gadget used the man-made radioactive element plutonium instead of uranium. Instead of a simple tube, the plutonium was formed into a near-solid sphere surrounded by explosives, a web of detonators, and acoustic lenses to make sure the resulting explosive wave imploded the plutonium sphere correctly to start the chain reaction.

Some sort of test would be needed to make certain that the plutonium bomb, which was subsequently used against the Japanese city of Nagasaki, would work. At first, the idea was to do a low-power explosion, but Oppenheimer opted for a full-scale test, which was code-named "Trinity."

By May, a 100-foot tall steel tower was set up at the Alamogordo site along with a base for 160 people, which swelled to 450 on the day of the test. Because of the high level of secrecy, the US Army accidentally bombed the area twice.

The Trinity shot tower
The Trinity shot tower

Like a Hollywood spectacle where the big scene means destroying the set, the test could only be done once. The Manhattan team set up cameras and instruments, including a lead-lined tank, to make sure that every millisecond of the test and every scrap of data was recorded. As the scheduled test time loomed, atop the tower and shrouded in tarps, the globe-like Gadget was assembled by seven men and the intricate networks of wires were connected to the detonators. Then the entire bomb was sealed inside a steel container called Jumbo that would prevent the plutonium from scattering if the test proved a dud.

As if there wasn't enough tension, there were also a string of electrical storms passing through the area, raising the prospect of the tower being hit by lightning.

About 10,000 yards away from the tower, shelters were set up. Among the Army personnel and the civilian scientists and technicians were Groves, Oppenheimer, and VIPs Richard Tolman, Vannevar Bush, James Conant, Brigadier General Thomas F. Farrell, Charles Lauritsen, Isidor Isaac Rabi, Sir Geoffrey Taylor, and Sir James Chadwick.

The Gadget assembled
The Gadget assembled

While waiting for the explosions, the scientists took dollar bets on how big the yield from the bomb would be. Edward Teller took 45,000 tons of TNT, Oppenheimer bet 3,000 tons, Rabi bet 18,000 tons, Hans Bethe had 8,000 tons, and Enrico Fermi took side bets on incinerating the state of New Mexico or the entire planet.

When the bomb went off, few actually saw the explosion. Most did as they were ordered and turned their backs. Others, like Teller, saw it using goggles and suntan lotion for protection. Meanwhile, a young Richard Feynman reasoned that the only real danger from the bomb at that distance was from hard ultraviolet rays, so he sat in an Army truck and watched from behind the protective glass windscreen, making him the only one to see the test with the naked eye.

We knew the world would not be the same. A few people laughed, a few people cried. Most people were silent.
Robert Oppenheimer

The Gadget detonated as planned, releasing a yield of 22 kilotons. The tower was vaporized, and a 5-foot-deep crater was blasted out of the desert floor, which was converted into glass by the tremendous heat flash, creating a new mineral called trinitite. Above the site, the first atomic mushroom cloud turned golden, purple, violet, gray and blue, rising 7.5 miles into the sky as a pair of B-29 bombers circled to record the event at a distance. On the ground, the observers felt a wave of heat like the open door of an oven.

The Trinity Test was the first detonation of an atomic weapon
The Trinity Test was the first detonation of an atomic weapon

"We knew the world would not be the same," said Oppenheimer in a 1965 interview. "A few people laughed, a few people cried. Most people were silent. I remembered the line from the Hindu scripture, the Bhagavad Gita; Vishnu is trying to persuade the Prince that he should do his duty and, to impress him, takes on his multi-armed form and says, 'Now I am become Death, the destroyer of worlds.' I suppose we all thought that, one way or another."

Today, the Trinity Site is a National Historic Landmark marked by a simple lava-rock plinth bearing a plaque that reads, "Trinity Site Where the World's First Nuclear Device Was Exploded on July 16, 1945."

As to what became known as the Bomb (with a capital B), it went on to end World War II and became the centerpiece of the Cold War, reshaping our world forever.

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9 comments
FB36
I for 1, think that, nuclear weapons is what really prevents WW3 & NOT really humanity became peaceful (after doing 2 WWs)!

Also, I for 1, think that, nuclear energy is a really useful tech to have for humanity, in many ways!
But it still needs technological advancements (obviously)!
My point is, some technological advancements require a very long time to really improve/mature
& just because it has any shortcomings in present time, does NOT really mean we should give up on that tech!
ikegami
The Jumbo was not used during the Trinity test. It would have been way too heavy to hoist up the tower.
Signguy
Like giving a 3 yr. old a sharp knife & telling him to be careful.
Cryptonoetic
The development and use of the atomic bomb saved between 20 and 40 million Japanese lives that would have had to be taken in a conventional war of occupation having the goal of unconditional surrender. The work of those great scientists and engineers was hardly edifying from a humanistic perspective, but by immediately ending the war it ultimately proved to be a compassionate work that saved the lives of tens of millions of Japanese as well as over a million allied casualties. In the vein of "God created men equal, Colt made them equal", these terrifying weapons have since kept the world from descending into another global conflict. In the immortal words of WHOPPER, "The only way to win is not to play at all."
Catweazle
Well said FB36.
joe46
@FB36 I agree 100%
toni24
There is mounting evidence that Nazi Germany actually beat America to the punch on the atomic bomb. Previous arguments that germany did not have the infrastructure necessary to produce the Uranium 235 needed for a critical mass bomb has been refuted by historical l records discovered recently. In 1942 Enrico Fermi suggested a better disign, one that did not require nearly 11kg of U235 for detonation, he suggested a hollow cored design that used Li6 and Deuterium in the core to boost the Neutron supply so that only 159 to 299 grams of U235 would be sufficient and produce the same effects as the Hiroshima and Nagasaki bombs, whch weighed nearly 5 tons. This recent evidence indicated that this was the path that Germany followed. Look it up. Type Nazi A bob in your search engine.
Of course the Allies could not afford to let world know how close the race really was. So they confiscated every bit of material and evidence they could find. Our Government would do this, they have not changed ,just look at how deceitful they are now
a.l.
And in reply to Toni24:

Not not is there no evidence that the Germans were close to building a fission bomb, but it’s well documented that, while the Nazis had great faith in engineering, they had little in pure science (sound familiar?), especially theoretical physics, which they derided as “Jewish science,” leading them to expel many of their best physicists in the years leading up to the start of the war.

There may be no better gauge of the state of Germany’s stillborn nuclear program than the incident described by Thomas Powers in his excellent history of that effort, “Heisenberg’s War,” in which German physicists, who’d been captured by the British and held incommunicado in a country manor house following Germany’s surrender, were allowed to hear the news of the Americans’ dropping of their “Little Boy” bomb on Hiroshima. The Germans were incredulous, not believing that the U.S. or any nation could have achieved a working fission bomb in the “mere” three and a half years since America declared war on the Axis. They knew, moreover, the their own government’s limited finances and resources and it’s inability to construct the massive facilities necessary to produce an adequate amount of fissile material and place it where it would not be subject to Allied bombing raids or saboteurs.

No one knew better the state of German nuclear research than those German scientists. Their disbelief at the American achievement is the most succinct and eloquent disabuse of any revisionist notions that Nazi Germany could have, or would have, produced a bomb.
alm
asian lives matter: no more nuking, mass bombing, agent organge spraying, enslaving, colonizing, terminating etc of asian lives