Short History Of... - The Manhattan Project

Episode Date: June 15, 2025

The Manhattan Project was the codename for the US government’s top secret programme to develop the first atomic bomb. At the height of World War Two, America’s top scientists - such as Dr Robert Oppenheimer - raced against Nazi Germany to harness the power of nuclear fission, and ultimately end the war. But what is the story of the other scientists, soldiers and civilians who brought about the birth of the A-bomb? What role did Albert Einstein play in the project? And what were the consequences when the bomb was finally used? This is a Short History Of The Manhattan Project. A Noiser Production, written by Jo Furniss. With thanks to Dr Cameron Reed, a physicist, and the author of ‘Manhattan Project, The Story Of The Century.’ Get every episode of Short History Of a week early with Noiser+. You’ll also get ad-free listening, bonus material, and early access to shows across the Noiser network. Click the Noiser+ banner to get started. Or, if you’re on Spotify or Android, go to noiser.com/subscriptions. Learn more about your ad choices. Visit podcastchoices.com/adchoices

It is approaching 5 a.m. on the 16th of July 1945. A storm is passing over the desert of New Mexico and the United States of America. This barren area is known as Juanada del Muerto, or Dead Man's Root. But today, as lightning splits the sky, it is alive with activity. A man gets out of an army jeep and walks into a bunker. As he enters the room, he finds an atmosphere of tense excitement. They're here to conduct a test that has never been tried before.

And it's this man, Dr. Robert Oppenheimer, who is in charge. No one knows what to expect, not even Oppenheimer, but some of his team have taken bets on the possible outcomes. One, they will be blown to bits. Two, the experiment will be a humiliating dud. Or three, its success will change the course of history. At 5.10 a.m., a 20-minute countdown begins. The experiment is the culmination of years of work, undertaken by what is known as the Manhattan Project.

This location has been chosen because it is remote, flat, and there is usually very little wind. Three vital factors which prompted Oppenheimer to name this test site Trinity. He peers out through a peephole cut into the soil bank of the bunker. The shelter stands over five miles from ground zero, the actual site of the test, so Oppenheimer can barely see it. But he knows every detail. Out in the desert stands a 100-foot tower upon which rests a strange-looking ball. A metal globe about the height of a car, it is covered with black wires that loop between shiny nodes dotting its surface.

The cables connect to a control panel. This sphere is known as the gadget, a playful name given to the most dangerous object ever created by human hands. A red flare fires into the sky. It signals the five-minute warning. All around the vast test site, at observation posts placed at least ten miles from the gadget, the men and women working on the project will recognize this as the signal to lie down, arms over their heads, feet pointing towards ground zero. Oppenheimer wonders how many will be tempted to watch. How many will panic? A second flare arcs across the sky.

Two minutes. It is too late to turn back now. At least the weather forecast was correct. Crucially, the wind has dropped. Oppenheimer takes hold of a wooden post to steady himself. The last seconds tick down and then, finally, it is time. Everything turns white. Perhaps this is it. The end of the world. Then the horizon reappears.

And intense light unfurls a shimmering carpet across the desert. The sand turns gold, violet, blue. Around Oppenheimer there are cheers and applause, wild laughter. He watches as a ball of fire grows into a mushroom cloud, and then the sound of the explosion hits them. It is followed by a roar of hot wind. Oppenheimer closes his eyes. The test has worked. They have made an atomic bomb. they have made an atomic bomb.

But while the others celebrate, you can only think of a line from a Hindu holy text. Now I am become death, the destroyer of worlds. The Manhattan Project was the code name for the US government's top secret program to develop the first atomic bomb. It was a science experiment on an industrial scale, run with military precision at breakneck speed. At the height of World War II, the race was against Nazi Germany, whose scientists were also trying to harness the dangerous power of nuclear fission. The project has become synonymous with one man,

the physicist Dr. Robert Oppenheimer, the so-called father of the atomic bomb. But what is the story of the other scientists, soldiers and civilians who brought about the birth of the A-bomb? What role did Albert Einstein play in the project and what were the consequences when the bomb was finally used? I'm John Hopkins from the Noiser Network. this is a short history of the Manhattan Project. Far from being the work of just one team, the creation of an atomic weapon is the culmination of several centuries of scientific development. In 1789, a German chemist called Martin Klarprott examines a mineral taken from a silver mine

in what is now the Czech Republic. Within this ore, known as pitch blend, Klarprrot discovers the oxide of a dense metallic element. He names it uranium after the newly discovered planet of Uranus. A century later, French physicist Henri Becquerel notes that uranium salts emit invisible rays of energy, or radiation. Building on his work, the scientist Marie Curie then pioneers research into what she and her husband Pierre call radioactivity. Curie's conclusion is that the process can occur inside an atom. A radical idea, as scientists had previously believed that atoms were the smallest units of matter. The word atom even comes from the Greek atomon,

which means something that cannot be divided. But at a laboratory in Cambridge in 1932, two physicists do just that. John Cockroft and Ernest Walton build a particle accelerator and split a lithium atom by bombarding its nucleus with protons until it splits into two helium nuclei. A few years later, in the late 1930s, chemists in Berlin go one step further and split uranium atoms. But it's their colleague, Dr. Lisa Meitner,

who interprets their unexpected results. As a Jewish woman, she has already fled to Sweden to get away from the anti-Semitic regime of the Nazi party. Now, in exile and working far from her colleague' lab, she helps to identify a new process they call nuclear fission. This means not just dividing a single atom, but creating a chain reaction. One neutron causes the nucleus of an atom to divide, which releases more neutrons that

cause other nuclei to divide, and so on. The process releases a massive amount of energy. At once, researchers recognize its potential, and not just for the production of power. Dr. Cameron Reed is a physicist and the author of several books including Manhattan Project, The Story of the Century. So there were research groups in Paris, Berlin, Rome, London, America that could have stumbled into that. And it was a quasi accidental discovery.

It was late 1938 in Berlin, Germany. So you know, you have Hitler in power. You're within a year of the start of World War II. It was a striking discovery. And so the fact that it released a lot of energy, millions of times the energy of a chemical reaction, and that it also emitted neutrons that could cause a chain reaction, was appreciated very quickly.

It only took a matter of weeks before people who were aware of this in fact began speculating that a bomb might be possible. One person who understands and fears the potential of nuclear fission is Albert Einstein. In 1938, the world's most famous living scientist is also in exile. A few years earlier, when Adolf Hitler and the Nazi party came to power in Germany, Einstein was on a visit to America. Due to his Jewish heritage and opposition to Nazi ideology, he decided not to go home. In fact, he would never return to Germany or Europe again.

Einstein is just one of hundreds of Jewish scholars forced to leave their homelands and look for refuge at institutions in America, Britain or other safe havens like Scandinavia. But though displaced, he keeps working. He follows the developments of two former colleagues, Leo Szilard, a Jewish physicist from Hungary, and Enrico Fermi, who fled fascist Italy because his wife was Jewish. They had already come up with a theoretical model for nuclear fission and patented it, but were beaten to a practical experiment by the scholars in Berlin.

These people would read each other's papers. Many of them had studied with each other and kept in contact. And there was a lot of communication, you know, within the community. And they'd visit each other's labs, they'd see each other at conferences, so they were well aware of what each other was working on. Based at the University of Chicago, Szilard and Fermi wanted to draw the attention of

the US President Franklin D. Roosevelt to their project and warn him that the technology is now in development in Germany. So they enlist the help of their illustrious colleague Albert Einstein. They were otherwise unknown refugee physicists. How do they get a letter to the president? And so the rationale was that, well, at least the president would recognize Einstein's name. He's going to take that seriously. And so Einstein didn't draft the letter himself.

These other guys did, but it was over his signature. There is a similar letter in Britain in the spring of 1940 by two refugee physicists in Birmingham. And this went up to the British Defense Ministry, but their memorandum was much more technically detailed and estimated critical masses and bomb yields. And it was really a draft of technicalities of making a bomb. And in that respect, it was much more detailed than the Einstein letter. And that started the British effort at the same time.

It's the same physics in Berlin or Washington or London, and so there was a number of efforts started up about that time going in parallel. A month after Einstein sends his letter to President Roosevelt, Germany invades Poland and Europe is once again at war. Titanic ship of dreams, the new podcast from the award-winning Noiza Network. Join me, Paul McGann, as we explore life and death on Titanic. I'll delve into my own family story following my great-uncle Jimmy as he tries to escape the engine room. We'll hear the harrowing tales of the victims and the testimonies of the lucky survivors.

I saw that ship sink and I saw that ship breaking off. Titanic Ship of Dreams. Listen wherever you get your podcasts. It takes Roosevelt several months to reply to Einstein. But when he writes back, it is with news that he has ordered a study of uranium. Roosevelt seemed to have an intuitive grasp that this could be really important and that even if it was very speculative to begin with, it can't be ignored. Because of course, Roosevelt was convinced, obviously, America was going to be in war

and the idea that any country that didn't have such a weapon could not possibly prevail against one that did. Einstein's old friend Leo Szilard attends the first meeting of the Advisory Committee on Uranium in Washington, D.C. on October 21, 1939. Einstein is invited, but declines. And although his letter influenced Roosevelt, it will be the end of Einstein's involvement with the project. Even so, the wheels are now in motion. The US government now funds Zillard and Fermi's project to develop a nuclear reactor. But the preparation of the necessary uranium poses a challenge.

The element itself is not rare. It is found naturally in rocks, soil and even water. But these are trace elements. For commercial quantities, it is necessary to extract the useful element from ore. This process of separating uranium, which can only happen atom by atom, is known as enrichment or purification. When it comes out of the ground, the ore contains two variant forms, uranium-235 and uranium-238. Only the former can be fissioned and therefore used for weapons.

And unfortunately for the scientists, less than 1% of the ore contains uranium-235. Early in 1941, however, a chemist called Glenn Seaborg working at the University of California in Berkeley finds that when uranium-238 is bombarded with particles and the resulting element is left to decay, it produces another, new element. At first, this is known simply as element 94. Until, following the convention of naming after planets, Seaborg calls it plutonium. Plutonium hardly exists in nature, but chemists can make it in the laboratory. They realize that it is fissile. In other words, it can be used to create nuclear fission. I guess the dilemma that's faced is, you have these two possibilities, enrichment and creating plutonium, both will be very difficult.

Nobody knows what might actually work in reality. We better do both. So that was the decision that was made to pursue both possibilities. Who knows what the Germans could be doing. Amid all this activity, the clock suddenly starts ticking louder. Early in the morning of December 7, 1941, two waves of Japanese fighter planes drop bombs and torpedoes on American warships in the US base of Pearl Harbor in Hawaii.

The attack kills over 2,400 US sailors, other military personnel and civilians, and drags the Pacific region into the Iranian committee. Ten days after Pearl Harbor, the US Army holds the first meeting of what will become known as the Manhattan Project, named after the Army headquarters in New York City. Its leader, General Leslie Groves, is in charge of the research, military capacity, and security around the development of the world's first atomic bomb. He must deliver all of this in secret, despite eventually employing a staff of scientists, soldiers, and civilians, numbering tens of thousands.

The responsibility for this is given to the army because they had a huge budget. And Groves' position at that time was that he was an engineer and he was in charge of all military construction within the country. So every munitions factory and fort and air base and airplane factory, he is organizing the contractors for. And his immediately preceding big project had been the construction of the Pentagon. So he knew all these contractors across the country that could take on big jobs and do them on

time and on budget and keep the appropriate secrecy. So he was really the driving force of this thing. The pieces of the puzzle Groves must assemble are spread far and wide, literally, in different parts of the country. First, they need to enrich uranium. At a new site in Oak Ridge, Tennessee, they pursue three different processes. To accommodate the huge numbers of staff, a new town springs up, with houses, homes, stores, schools, even theatres and parks. The population skyrockets, and in the early 40s, one specialist plant there claims to

be the largest building in the world. The work carried out at Oak Ridge is fundamental to the overall project, isolating the precious explosive core of the future bomb. They weren't efficient processes, they were quite inefficient, so you'd need tons of input material to get a few kilograms, ultimately, of the desired version of uranium. One method is to use an electromagnetic device called a calutron. This machinery is usually run by a team of scientists, but the war has led to a shortage of staff. So around 10,000 young women, mostly high school graduates, are trained up to do the

job. Though the purpose of their work is kept top secret even from them. The process of enriching uranium depends on vast quantities of the original uranium ore. Though there are mines in Colorado and Canada, by far the richest and most plentiful source lies in what is at the time the Belgian Congo. But how to get hold of materials from so far away during wartime? Here, General Groves has a stroke of luck.

A Belgian man named Edgar Sengier is an engineer in charge of a uranium mine in the region and is well aware of the potential applications of his product. With Europe at war, he doesn't want the Nazis to get hold of his huge stockpile of uranium ore, so he ships half the entire reserve to a warehouse on Staten Island in New York. In September 1942, Groves sends a lieutenant to Sengier's New York office to explore the possibility of getting ore sent over from Africa. Sengier famously replies that he can have it right away. A thousand tons of it. He's been awaiting the call. There were very rich uranium mines in the Congo. And I think what probably was the main product

they were after was radium, you know, for luminous watch dials and that sort of thing. But the two often occur together. And it happened to be a very rich deposit of uranium ore, occur together and it happened to be a very rich deposit of uranium ore. 75% purity or something. You know, what a break for Groves because here's this stuff readily sitting in a warehouse in New York in drums marked uranium ore that he was able to buy. Groves buys the lot plus another 3,000 tons that's still waiting at the mine. So one problem down, but there are many other challenges to overcome. To build an atomic bomb, the scientists need to prove that nuclear fission will work as they expect and that they can control the process. To do that, they need a nuclear reactor.

It is December the 2nd, 1942. A young woman in a tweed jacket hurries through the cold morning at the University of Chicago. As a physicist, Dr. Leona Woods is more accustomed to academic lecture halls. But today, her footsteps crunch across the frozen grass of Stagg Field, where American football is played. In the past, she sometimes played squash in the courts tucked under the grandstand.

Now she works there. She clocks into the facility. Inside is a hive of activity with people bustling and machinery whirring. The squash courts have been taken over for a new purpose, a secret laboratory. In recent months workers have constructed a prototype nuclear reactor. It comprises 45,000 black graphite bricks, stacked up around 22,000 rods of uranium. These are arranged in a complicated lattice that rises 20 feet high. Dr. Woods joins almost 50 other scientists. Their leader, the Italian Dr. Enrico Fermi, approaches and asks Dr. Wood to prepare the

specialist equipment that she herself invented. She sits down in front of a bank of switches and counters, ready to record the feed from her boron trifluoride meters that will detect if the test today is successful. Fermi retreats to a viewing platform and orders everyone except a few men to leave the area around the reactor. One lone volunteer is ready to start the process of a nuclear chain reaction. Another team of three students stand on top of the device armed with buckets of cadmium solution. They are effectively firefighters, as the cadmium will absorb neutrons and slow down the reaction if it gets out of hand. At least that's the theory.

Though Dr. Fermi believes he can control the reaction, this is the first time the technology will be tested on this scale. With no radiation shield or cooling system, everyone here must simply trust in his calculations. Now he gives the word. The volunteer beside the hive slides out a cadmium rod from between the bricks. Everyone holds their breath. Dr. Woods busies herself with adjusting switches and scribbling readings. She can tell that inside the reactor, invisible to the naked eye, alchemy is taking place.

Finally, electrical meters start to click. The sound rises to a buzzing hum. Dr. Woods shows Dr. Fermi her findings. Deep inside the graphite structure, a chain reaction is underway. Leaving Dr. Woods to her work, Fermi orders an operator to send a coded telegram to the rest of the Manhattan Project team. As the paper spews from the machine at the other end, it reads, the Italian navigator has landed in the new world. Nobody had ever built a reactor before.

It operated at less power than a flashlight battery, like half a watt. You couldn't light a light bulb with this thing. But it did demonstrate that the theory was correct, that a chain reaction could be created and controlled in such a way as to synthesize plutonium ultimately, that that would have to be scaled up. To me it's remarkable that his first reactor produced about half a watt of power. Within two years that scaled up to three reactors, each running at 250 million watts to get the scale of production.

You know, it's like going from a paper airplane to a 787 in two years, you know, it's remarkable. In order to create the amount of power needed for the Manhattan Project, they need a much larger reactor. Groves orders a new facility to be built in Hanford in Washington state, alongside the Columbia River. Here, the focus is on the synthesis of plutonium, while the other super-site at Oak Ridge in Tennessee works on uranium. He initially considered putting both of these in Tennessee, but then decided that, well,

we have two very different processes here. If there's a catastrophe at one of them, it could wipe out the whole thing. And it helped with secrecy in the sense that if somebody had been employed in Tennessee but left, they would not be considered for the site in Washington and vice versa. So it could help them keep things compartmentalized, as he called it. With construction underway, Groves is still putting together his dream team of academics. Around this time, he meets the man who will become known as the father of the atomic bomb.

Robert Oppenheimer is a theoretical physicist who was born in New York, partly educated in Germany and is now working at the University of California in Berkeley. A tall, thin, chain smoker with bright blue eyes, he is not only a brilliant scientist but a polymath. A man who reads poetry and who has learned several languages in order to appreciate literature in its original form. Though not the most senior scientist that Groves meets in his search for a team, he shows a breadth of knowledge and a level of ambition that impresses the general. Soon he's helping make key decisions.

So there is research going on in New York and Chicago and Berkeley, various places, and so Oppenheimer suggested that you need to centralize this work because it's being duplicated in a lot of universities and you really need a centralized lab where all these people can get together and yes it would have to be remote and secret, but you need to coordinate this work. And so I guess you could say the rest is history and Groves picked Oppenheimer to run this. The centralized location is a place called Los Alamos in New Mexico. Nearby is an area known as Jornada del Muerto, or Dead Man's Route. Remote, flat, and almost uninhabited.

In other words, a perfect test site for an A-bomb. If they ever get that far. It's just out in the middle of nowhere. And there had been a wilderness boys' school there, which they appropriated because it had some buildings to use for housing. But basically, they had to build this lab from scratch. So you have places like Harvard shipping our cyclotrons to Los Alamos to be reassembled and brought into working condition.

So to go from that, you know, within a couple of years to probably what was one of the best equipped research labs in the world. I guess it shows you how serious they were about what was going on. So now uranium-235 is being produced at Oak Ridge, Tennessee. Plutonium is being synthesized in Hanford, Washington and at Los Alamos, Oppenheimer and his thousands-strong team work on bomb design. They discover that two different devices will be required to accommodate the contrasting properties of uranium and plutonium.

The uranium bomb is relatively simple. Shaped like the barrel of a gun, it holds uranium at the end of a tube and a conventional explosion inside the cylinder will trigger the chain reaction that leads to an explosion. The simplicity of the uranium bomb was that they were very confident it would work. And they had only enough U-235 for one bomb at that point. And it was going to be weeks and weeks before they had more. So they were confident that one would work.

But in the plutonium bomber, you've got this implosion technique. They had done hundreds of test implosion experiments. But basically, you're trying to arrange explosives to blow inwards symmetrically with chunks of explosives, all within a microsecond of each other. So it was a very tricky job for the electronics people to get this to work. And they felt they just, they were so uncertain about whether that would work, they felt they had to test it. And the plutonium production was ramping up in Hanford

and so they had enough to be able to spare for a test and have enough left for an actual bomb. and have enough left for an actual bomb. The complexity of the device requires experts from multiple fields of study. Scientists and civilians, all working together in the remote heat of the New Mexico desert. There is a lot of civilian folks at Los Alamos, not just the engineers, but chemists and metallurgists to cast them into relevant shapes. There was a lot of electronics people, a lot of what would now be called computer programmers.

That whole division of people were doing calculations of simulations of, okay, what can we expect from this thing? How much energy should it release? How much destruction would it cause? So there was a large nascent computing effort at Los Alamos. They had meteorologists on staff that were predicting the weather as the test approached. So all kinds of things you wouldn't initially think would be part of a nuclear physics lab. As the months pass, the war drags on.

Some at Los Alamos fear that, despite all their efforts, they will be too late to produce a weapon in time to change the course of the conflict. Or even worse, the Germans will get there first. The Nazis could produce an atomic bomb and hold the world hostage with just the threat of a nuclear strike. Also, the Germans had a head start. It is already seven years since their scientists first carried out nuclear fission in a laboratory in Berlin. The Germans simply did not get very far.

I think there's various reasons. They had a reactor development program, but it involved only a couple hundred people. They never achieved an operating reactor, unlike Fermi. And you'd think the Germans would be organized about such a thing. In fact, they were rather disorganized. So there wasn't a personality like Groves with that intense organization and making the upper levels of the government come to realize how significant this could be. Apparently, Hitler had been briefed on it, but at a very speculative level. You know, I think it's

been estimated that the amount that the Germans spent on their program wasn't even a thousandth of the Manhattan Project. In fact, it will eventually cost the United States over $2 billion to fund the Manhattan Project. It will also depend on the brilliant minds of many of the European and Jewish scientists who have taken refuge in the United States. But for now, staff at all the sites are working against the clock to produce the core materials, uranium and plutonium, and the devices needed to turn them into weapons.

In April 1945, President Franklin D. Roosevelt dies of a cerebral hemorrhage while still in office. His vice president, Harry Truman, takes the oath of allegiance the following day and only then learns about the existence of the project, such as the level of secrecy. In his diary that night he writes about a weapon great enough to destroy the whole world. He also notes that the Germans probably don't have the resources to develop it, but the Russians might. The Nazis are now close to defeat, and before the month is out, Hitler commits suicide in his Berlin bunker. A week later, Germany surrenders. The war in Europe is over. But Japan vows to fight on.

Reluctant to abandon its project of expansion into resource-rich parts of Southeast Asia and the Pacific, it also fears the occupation and loss of cultural independence that could follow should it surrender. As summer approaches, the threat to the United States from across the Pacific remains active. There is no let up for Groves and Oppenheimer at Los Alamos. By the summer of 1945, they had enough of this variant of uranium for just one bomb. This must be one of the few times in military history where a significant new weapon is deployed

without a full-scale test beforehand. The first test was really Hiroshima. In July 1945, the one and only uranium bomb is loaded onto a ship for transport across the ocean to the United States bases in the Pacific. On the very same day, Oppenheimer decides that conditions are right to test the second type of weapon. for transport across the ocean to the United States bases in the Pacific. On the very same day, Oppenheimer decides that conditions are right to test the second type of weapon. Plutonium production has been more efficient, so they have enough for a trial run of the more complex device.

It will become known as the Trinity Test. In the desert outside Los Alamos, a 100-foot tower is constructed. A sphere containing the plutonium, the so-called gadget, is hoisted onto the platform, and Oppenheimer takes up position in a bunker. Groves is present, as is Fermi, who built the first nuclear reactor. Various personnel at outposts outside a 10-mile exclusion zone make observations. Military aircraft circle to take readings. At 5.30 a.m. on July 16, the world's first atomic bomb is unleashed.

The tower holding the gadget is incinerated. The sandy ground around the device is turned into a sheet of green glass. Witnesses as far as 200 miles away see a flash. After the test, a press release is issued, simply stating that a considerable amount of explosive had been detonated without loss of life or limb. The people of Oval were taking bets on whether or not this thing would work. They were taking bets on how much energy it would yield. And so the bets were going from everything from zero to a hundred kilotons.

And apparently Enrico Fermi alarmed all his colleagues by speculating they could set fire to the atmosphere, which was a total red herring. But I guess it shows you the mindset they were under at the time. Even Oppenheimer himself underestimated the power of the weapon. In the event, the plutonium bomb releases the equivalent of 21 kilotons of TNT. It is hotter than the surface of the weapon. In the event the plutonium bomb releases the equivalent of 21 kilotons of TNT. It is hotter than the surface of the Sun. The Trinity test of the plutonium weapon is a success and the uranium device is already on its way across the Pacific. But there are those, even among the scientists, who start to have their doubts about using the weapon against civilians. Under pressure to give the Japanese a warning, on July 26, President Truman issues a notice,

the Potsdam Declaration, in which he calls for them to stand down. In addition, leaflets are dropped over Japan, alerting civilians about the most destructive explosion ever known to man. But the Americans do not categorically spell out that they have a nuclear weapon in their arsenal. When the Japanese ignore the Potsdam Declaration, the US decide to go ahead with the plan to bomb its mainland. They had identified about half a dozen Japanese cities that had not been bombed,

that had geography that would let them, you know, test the effects of the bombs were large enough. Hiroshima was a big army base, Japanese army base. So they didn't just drop these things willy-nilly on somebody. They had a list of about half a dozen potentials and Hiroshima, Nagasaki, Kokura were at the top three. And Nagasaki, I think there's some morbid irony here

in the history, Nagasaki was where the torpedoes used at Pearl Harbor had been made. It's 2.45 in the morning of August the 6th, 1945, on Tinian Island in the Pacific Ocean, around 1400 miles south of the coast of Japan. After completing his final checks, Colonel Paul Tibbets is cleared for takeoff. He accelerates his plane down the runway and up into the endless black of the night sky. The Propeller plane is a B-29 Superfortress, modified especially for this mission. The usual armor and guns have been stripped off, otherwise given today's 5-ton payload, it would barely get off the ground.

Tibbits soon has them cruising at an altitude of 36,000 feet. Their only on-board defense is a tail gunner, though they are accompanied by two other B-29s who can provide cover if necessary. Slowly the sun comes up across the Pacific. The aircraft's lightweight silver plating gleams, its name picked out in black capitals just under Tibbet's window at his request. Enola Gay, after his mother. After six hours, the crew spot the islands of Japan rising before them. Their target is the city of Hiroshima. As they approach, two weapons experts clamber down into the bomb bay

to make the final activation of the device. It is code-named Little Boy, even though the black cylinder contains the biggest explosive ever deployed in combat. Bombardier Tom Farabee shouts that he has visual confirmation of the target, a distinctive T-shaped bridge over the river Ota. Tibbets instructs his crew to put on protective goggles. The hatch opens and little boy drops into the air. As one of the men makes the sign of a cross, Tibbets puts the B-29 into a sharp 155 degree turn.

The crew are thrown side to side until their pilot straightens up and gives the engine full thrust, putting as much distance as possible between them and the explosion. No one knows if the blast will tear the aircraft to shreds. Someone shouts aloud, 1000, 2000, counting the seconds of little boy's descent. 3000, 4000. Radar operator Jacob Besar tracks the bomb with more accuracy on his screen. It is still falling. Will it detonate or not?

Enola Gay roars through the air. They keep counting. 30,000. 40,000. The bomb must be a dud. Then, ten miles and forty-three seconds later, the sky turns white. Moments later, the aircraft jerks in the shock wave. It jolts again from an aftershock. Warning lights and alarms sound, but Tibbets keeps his shaking hands on the stick and flies on. In the tail gun position, Staff Sergeant George Caron raises his camera and snaps a photograph of a purple mushroom cloud boiling upwards into

the morning sky. The Hiroshima mission was regarded as a textbook mission. Not all of the crew had been briefed on it. Once they got into flight, then the pilot would describe, okay, this is the first atomic bombs in history. So a lot of the ordinary crew members were only told their final mission when they were in flight. These were all experienced combat crews.

A lot of them had been in missions in Europe. And so they knew as soon as this thing went off and they witnessed it that this was much more destructive than any ordinary bomb. One bomb was taking out all square miles of the city. In fact, one of the crew members was keeping a diary. He recorded that when he witnessed the bomb, he wrote, my God, what have we done? So this was an experienced combat crew member. So they must have had an immediate sense that this was something very different. This was changing the world. An estimated 80,000 people die in the immediate blast. Almost a third of the population of

Hiroshima. Many are killed by a fireball that is hotter than the sun, while others suffer flash burns from a blast wave over two miles in diameter. Thousands more die as buildings collapse and glass shatters. Three days later, the plutonium-fuelled bomb called Fat Man is dropped too. This time, however, the mission is less straightforward. The weather is bad, the fuel gauges play up, and cloud cover prevents the bombardier from getting a visual on Kokura, the target city.

With fuel running perilously low, they drop the payload when there is a small break in the clouds over Nagasaki. They barely manage to get back to the US airbase in Okinawa. They barely managed to get back to the US airbase in Okinawa. The plutonium weapon is more powerful, but thanks to shelter provided by the city's hilly topography and the fact that the bomb detonates over a less densely populated industrial zone, the number of casualties is about half of those in Hiroshima. Nevertheless, the death toll climbs steadily after the bombings. People succumb to physical injuries like burns. Deaths from radiation sickness

peak about three weeks later. In the longer term, people starve due to the destruction of vital infrastructure. The death toll is higher than even the bombs makers had foreseen. Oppenheimer is quoted as warning that 20,000 could die, but some estimates put the total number at 10 times that amount. They must have known this was going to create immense casualties. You couldn't avoid it. So you So, you know, you read some of the memoirs of these people and there's often a sense of mixed

feelings that, well, you know, pride in that they had contributed something to the end of the war. They had used their experience and knowledge to contribute to this thing and it worked. And they could take pride in this immense accomplishment, but at the same time they've been involved in this horrendous thing. The Japanese surrender six days after the second attack. The following year, President Truman signs the Atomic Energy Act, which puts the nuclear program into civilian control. The Manhattan Project itself is closed in 1947, but dealing with what it leaves behind takes rather longer.

Vast amounts of waste were created by the rapid production of radioactive material, with huge tanks used to store it. of radioactive material, with huge tanks used to store it. In the heat of the race to end the war, dealing with these pollutants was put off until later. The complicated cleanup process is ongoing today, one that some estimates claim will cost more than the original venture. But though the Manhattan Project is over, Oppenheimer and his team have let a genie out of the bottle. The US spent billions of dollars to set up industrial-scale nuclear facilities. Despite the end of the war, the reactors keep running, the laboratories keep researching.

The United States wins the race to develop an atomic bomb, but they cannot keep guard over the technology forever. Oppenheimer had perhaps hoped that that could be controlled, but the Russians had spies at Los Alamos. They were well aware of what was going on. Stalin was well aware of what was going on and in fact instructed his own scientists to begin work. And they had some sketches of the design

of the Trinity weapon. So after the end of the war, the Russians got their own reactor operating within about a year, and it took them only four years to reproduce the work. Then of course, any country that would have fancied itself as a world power would have felt they'd have to have their own nuclear weapons program.

So within a few years you have Russia, Britain, France, China beginning to pursue these things. By the 1950s, the ideological opposition between America and Russia has never been more stark, but both now possess atomic weapons. Geopolitical tension ramps up and mistrust grows as both sides fear that the other could be the first to push the button and launch a nuclear strike. Neither superpower can act, held in the stalemate of what becomes known as mutually assured destruction. For his part, Oppenheimer falls out of favor in the aftermath of the war. Telling the media that he feels he has blood on his hands, he becomes unpopular with the White House. In an atmosphere of anti-communist hysteria, his enemies drag up historic connections to left-wing politics

and use those to sideline him. But other scientists continue his work. Though their roles have evolved, all three of the main Manhattan Project sites, Oak Ridge in Tennessee, Hanford in Washington, and Los Alamos in New Mexico, are still working today. The American model of large-scale government-funded research projects carried out by teams of scientists sets a precedent that continues to be known as big science. Prior to the war there were no federal research grants, or maybe very limited. There was no national institutes of health or national labs. It was all university-based stuff, and obviously there was no space program.

So that set the template for big science projects like Apollo and the internet, national laboratories and National Science Foundation and all of these really changed the relationship between science and government. They saw that sort of thing hadn't existed previously. With the war that precipitated it now almost out of living memory, it's no easier to balance the ledger of the Manhattan Project. Though it put an end to a bloody conflict that would have doubtless cost many more lives, by dropping just two bombs it caused the deaths of around 200,000 Japanese civilians.

And while the work of the Manhattan Project led to developments in nuclear power, medicine and other applications, the debate around whether the dawn of the nuclear age is a positive for mankind continues to divide opinion. It changed the world. So suddenly you have a weapon now that could take out a large city with a single blow. Oppenheimer likened it to two scorpions trapped in a bottle. Each can destroy the other, but only at the cost of themselves. So I guess it's changed the strategic landscape, you know, just so radically, and it changed how science and government and the military interact.

Once it became a huge military-industrial complex, it's far beyond his control. And I guess all of the proliferation and the politics were born on the day of the Trinity test. And I guess all of the proliferation on the politics were born on the day of the Trinity Test. Next time on Short History of... We'll bring you a short history of the Spanish Flu. What sort of impact did the Spanish influenza pandemic have on wider society? Surely a virus that kills so many people, you know, a quarter of a million people in Britain, 675,000 in the United States, 400,000 in France, 50 to 100 million people worldwide.

Surely people would have remembered that and recorded and built memorials to it. No, none of that happened. It's virtually impossible to find a contemporary memorial to the dead of the Spanish flu. But then the next question you have to ask yourself, well, how different is that really to what we see today with Covid-19? We've lived through the biggest pandemic in a century, but now five years later I get the impression that nobody wants to talk or think about it.

That's next time. If you can't wait a week until the next episode, you can listen to it right away by subscribing to Noiza Plus. Head to www.noiza.com forward slash subscriptions for more information.