How the atomic bomb appeared in the middle of a paradise – 07/21/2023 – Science

No one knows how many times physicist Robert Oppenheimer drove up the road from Santa Fe to Los Alamos. Under the blue sky, you travel between tortuous hills, you look at the bottom of precipices, sweeping landscapes are continually revealed. This is one of the most scenic stretches of New Mexico. Oppenheimer hoped the view would inspire his fellow scientists.

Los Alamos is a paradise and, at the same time, the place where the first weapon of mass extermination in history was developed. In the midst of this natural idyll, Oppenheimer directed the Manhattan Project, with which American President Franklin D. Roosevelt intended to win the race against Adolf Hitler’s Germany for the first atomic bomb.

For the military research project, the New York scientist of Jewish origin assembled a “spectacular collection of brilliant minds, the likes of which have never been seen before,” reports Heather McClenahan, director of the local Historical Museum. Among them were Nobel Prize winners in Physics Enrico Fermi, Niels Bohr and Hans Bethe.

In all, around 6,000 scientists and their families lived on the project’s premises — in addition to more than 125,000 employees in laboratories and production units spread across the country. However, it was to distant New Mexico that all currents converged, more precisely to the imposing building of Los Alamos Ranch School, a prestigious elite school, specially evacuated for this purpose in 1943.

As the central idea of ​​the project was developed in the neighborhood of Manhattan, in New York, it received the official title of “Manhattan Engineering District”, but later the denomination “Manhattan Project” was established.

Almost as expensive as a trip to the moon

In the wood-paneled main auditorium that served as a dining hall and meeting room, William Hudgens, one of Oppenheimer’s staff chemists, recalls wistfully more than 70 years later: “Everyone knew each other, there were no hierarchies.” During lunch, you could happen to end up, by chance, sitting next to the “super nice” project leader, whom everyone called “Oppi”.

The average age of the team was 26 years old. Hudgens remembers lots of parties and alcohol. However, at the same time, the atmosphere was very tense and the workload was enormous. “We were all very worried that the Germans would beat us to the bomb that would decide the war.”

The Manhattan Project was a top priority for the US government, with virtually unlimited resources. What began in 1940 with a budget of $6,000 grew to $2 billion within five years.

McClenahan reckons this was “the most expensive research project since the moon landing.” In addition to its centralizing function, however, Los Alamos had another, decisive purpose, as “a foundry for the project’s weapons”, emphasizes the museum director.

His goal was to prepare a nuclear weapon based on all available scientific data on uranium enrichment and the chemical purification of plutonium. For in the Manhattan Project, both the uranium bomb and the plutonium bomb were developed in parallel.

discreet memorial

On July 16, 1945, everything was ready to test the new weapon. The chosen one was the plutonium bomb, which was the more complicated of the two. The uranium bomb remained untested, as there was not enough enriched uranium for a second bomb.

The test area was the White Sands Missile Range, located over 300 kilometers from Los Alamos. At the time, 60 ranchers had to turn over their land to the US Army, says public relations adviser Lisa Blevin. She is the tour guide for the gigantic terrain, totaling 8,300 square kilometers, which the US Armed Forces only open to visitors once a year.

A 45-minute drive takes the group, made up mostly of physics and chemistry students from Los Alamos, to the site of the explosion. Only a slight depression of the terrain suggests a crater. From the security fences hang unkempt photos of the explosion, and a kind of obelisk commemorates the historic moment. Blevin confirms that the level of radiation there is ten times higher than normal, while noting that this radioactive load is lower than what you are exposed to during a four-hour flight.

German physics student Max comments, “I don’t like atomic weapons.” In his opinion, it would have been better not to build the bomb. On the other hand, it was good that the Cold War was “de-escalated” by the weapon. After all, there was no war between countries that had “nuclear possibilities”, concludes the 24-year-old.

deep doubts

On that day in the summer of 1945, physicist Oppenheimer and General Leslie R. Groves, general manager of the project, watched the test from a safe distance. Eyewitnesses would highlight the beauty radiated by the atomic mushroom and the luminosity of the explosion.

Just a month later, the US military dropped bombs on the cities of Hiroshima and Nagasaki, Japan. Many of the Manhattan Project scientists were startled to hear the news over the radio. Some had doubted until the last moment that the warheads would even work.

At the Los Alamos labs, “the prevailing feeling was one of relief, but there were no big celebrations,” recalls 90-year-old Hudgens. “We had no desire to celebrate something that had killed so many people.”

However, “the bombing saved millions of other lives by shortening the Second World War”, he says, adding that he is certain that many of the other scientists participating share this vision. For the chemist, this job was “a rare opportunity, and the best thing that could have happened in my life”. After all, that bomb changed the world, says Hudgens.

Robert Oppenheimer’s assessment was different. Now he had blood on his hands, he would later tell President Harry S. Truman during a White House talk. Deep doubts would accompany the scientist until his death, in 1967, aged 62.