Why did Oppenheimer poison his mentor? 23 details in the movie that are easily overlooked

Recently, the movie "Oppenheimer" is being released. The nearly three-hour movie tells the story of Oppenheimer from three aspects: his education, his participation in the development of the atomic bomb, and the political influence he suffered.

For such a biographical film, most people may have some questions after watching it: What was Oppenheimer like in the real world? Did he really poison his mentor? What stories are not shown in the movie? Today, let's go beyond the movie and take a look at the story of Oppenheimer in the real world.

01 Mushroom cloud with horns

The movie "Oppenheimer" opens with a nuclear explosion scene. Many people may have noticed that the round fireball of the nuclear explosion seems to have a "horn". This horn is a common phenomenon in real nuclear tests, but strictly speaking it does not come from the atomic bomb itself, but from the platform on which the atomic bomb is placed .

The picture is taken from the promotional video of "Oppenheimer"

The surface of a nuclear explosion fireball is over 20,000 degrees Celsius, and its light intensity is 100 times that of the sun's surface. These lights will quickly vaporize all nearby solids. In ground-based nuclear tests, atomic bombs are sometimes not actually placed on the ground, but on a small tower (as shown in the middle of the movie). In order to keep the tower stable, inclined cables are pulled from the top of the tower to the ground for support. These corners are the vaporizing cables.

The picture is taken from the promotional video of "Oppenheimer"

Physicists have conducted experiments and found that if the cable is painted black, it absorbs more light and the corners become more obvious. On the contrary, if the cable is wrapped with reflective paint or aluminum foil, the light absorbed is greatly reduced and the corners cannot be seen. And if it is an atomic bomb placed directly on the surface, exploded in the air, or underground, there will be no corners.

02Did Oppenheimer really poison his mentor?

In the movie, while studying at Cambridge University, Oppenheimer took a syringe and injected potassium cyanide (a highly toxic substance) into the apple of his mentor Patrick Blackett. In the real world, Oppenheimer did poison the apple, but the historical details are different from the movie.

Stills from the movie Oppenheimer

This historical incident occurred in the fall of 1925, when Oppenheimer fell into a very serious depression while studying in London. In fact, he liked his mentor Blackett and tried hard to seek his mentor's approval, but the mentor himself was an experimental physicist and arranged Oppenheimer to do experiments that he was not good at without thinking much. As a result, Oppenheimer poisoned an apple in extreme anxiety. He did not rush back to the scene to throw away the apple. Niels Bohr was not present at the time, and no one ate the apple, but the school still learned about it.

Oppenheimer himself confessed to his friends a few months later that "I used cyanide or something like that." However, this may be an exaggeration due to his mental instability . After all, if it was really a deadly poison, the consequences of being discovered should be far more serious. In fact, under the hard lobbying of Oppenheimer's parents, he was only punished with probation and was required to see a psychoanalyst regularly.

In the film, Oppenheimer later said in a conversation with his lover Jane Tulloch that he had been seeing a psychoanalyst for two years, referring to this experience and its aftermath. In history, there was indeed a psychoanalyst who gave the same advice as Jane.

03Is the dazzling light and shadow effect related to physics?

After Bohr's speech, the movie used a series of montages to show Oppenheimer's physical world. The good news is that those light spots, wavy lines and throwing cups are just pure visual effects, and they don't directly correspond to any advanced physics concepts related to the plot , so don't pay too much attention to them, just watch them for fun.

The picture is taken from the promotional video of "Oppenheimer"

Although there is no direct correspondence, there are some indirect connections if you look hard:

• The point-like objects could represent atoms or subatomic particles, or they could represent small particles of dust—one of Einstein's annus mirabilis papers was about the Brownian motion of dust.
• The fast jittering pattern of a linear object is close to an incompletely stable standing wave, which is often seen on an oscilloscope, but can also be considered to represent a quantum mechanical wave function or matter wave.

This movie is not a popular science film about physics, so don't pay too much attention to details like this. For example, the part where Oppenheimer talks about physics in Dutch is basically incoherent, because Nolan deleted many words from the original text in order to control the rhythm.

04This may be the book that helped Oppenheimer get out of depression

The historical opportunity for Oppenheimer to come out of depression was not Bohr's speech, but a trip to Corsica. Although it is not entirely certain what experience during the trip became the opportunity for Oppenheimer to come out of depression, it is generally speculated that he read Proust's "Remembrance of Things Past" . And meeting Bohr happened after Oppenheimer's trip.

What the movie shows but does not emphasize is that Oppenheimer was a sensitive and introspective literary youth throughout his life. Many years later, when he was in charge of the Institute for Advanced Study at Princeton, he introduced many literary critics and poets, including TS Eliot, the author of his beloved "The Waste Land" (although strictly speaking, his predecessor had already extended the invitation), despite the opposition of mathematicians in the institute.

Stills from the movie Oppenheimer

Oppenheimer really admired Bohr. Although Bohr was not the one who helped him get out of depression, nor the one who recommended him to Göttingen (that was Max Born), he was indeed the one who made him decide to give up experiments and focus on theory .

Oppenheimer and Bohr's first private meeting was in Rutherford's office. Bohr asked him, "How is your academic work going?" Oppenheimer replied, "I'm facing difficulties." So Bohr asked, "Is it in mathematics or physics?" Many years later, Oppenheimer would still sigh at what a profound question this was.

05 Oppenheimer's friend Rabbi and MRI

Isidor Rabi, who was on the same train with Oppenheimer, only played the role of Oppenheimer's lifelong friend and reminded him to eat in the movie (Oppenheimer in history was also extremely thin). In fact, Rabi himself was an outstanding physicist and won the 1944 Nobel Prize for discovering nuclear magnetic resonance - yes, the same nuclear magnetic resonance used in hospitals.

Stills from the movie Oppenheimer

In his later years, Rabi suffered from cancer, and the doctor used an MRI to examine him. The inside of the machine happened to be a reflective surface, so Rabi exclaimed, "I saw myself in that machine... I never thought that my research would turn out like this."

06 Oppenheimer’s teacher-student relationship

In the movie, the first student Oppenheimer accepted after returning to the United States was Lomanitz, and he explained the wave-particle duality to him. In reality, Lomanitz did not enroll until the early 1940s, but he was indeed pulled by Oppenheimer to participate in the Manhattan Project and was also one of the organizers of the left-wing labor union FAECT. After the war, he was one of the people who had the worst fate. He once fell into repairing railways for a living (there is a shot of him repairing railways in the latter part of the movie), but later he returned to academia. Oppenheimer's trial implicated many of his students and also affected the relationship between teachers and students.

07Early Black Hole Researchers

In the film, Oppenheimer tells the class that after a neutron star collapses, it will become a "dark star" - now you may know that he actually meant a "black hole". However, he only called this hypothetical celestial body a "dark star" at the time, and the term "black hole" would not be invented for decades.

Oppenheimer was one of the early black hole researchers. Throughout history, many researchers have approached the concept of black holes from different angles. The first person to describe a black hole mathematically was German physicist Karl Schwarzschild , who died of a disease contracted on the battlefield shortly after making this achievement in the trenches of World War I. Oppenheimer's starting point was different from Schwarzschild's, coming from the collapse of a neutron star rather than a direct deduction from general relativity.

08 Oppenheimer at the party

While flirting with a lady at a party, Oppenheimer said that solids cannot pass through each other because of quantum mechanics. To be precise, this is because of the Pauli exclusion principle of quantum mechanics: two fermions cannot be in the same quantum state. The electrons in atoms are fermions. Although the inside of atoms seems to be empty, if they are filled according to common sense, it means that too many electrons share the same quantum state, which is not allowed to happen. Therefore, atoms cannot be too close, and solid substances cannot pass through each other.

Pauli (who does not appear in the film) was Oppenheimer's teacher. Although both were physicists with outstanding theoretical achievements and terrible experimental results, Pauli did not think highly of Oppenheimer. Once, Pauli said that Oppenheimer's " physics was like a sideline, and psychoanalysis was his main job ." Another time, Pauli attended Oppenheimer's seminar and kept interrupting. Finally, physicist Kramer couldn't help but say, "Shut up, Pauli. You can explain how wrong he is later."

Wolfgang Pauli, Image source: Wikipedia

By the way, at the party, Oppenheimer and Jan boasted that he had read all three volumes of Capital and summarized it as "ownership is theft", but Jan corrected him and said "property is theft". But in fact, this slogan was proposed by anarchist Proudhon in his book "What is Ownership?" in 1840, not from Capital. Marx himself later criticized this slogan, believing that it was self-contradictory, and the concept of "theft" itself presupposed the existence of property.

09 Lawrence, the physicist next door to Oppenheimer

Lawrence was Oppenheimer's friend at Berkeley, an outstanding physicist and Nobel Prize winner, but he had many political disagreements with Oppenheimer. He believed that although what happened in Europe deserved sympathy, it was not the Americans' business after all, and he had repeatedly advised Oppenheimer "as an excellent physicist, don't get involved in politics." In history, Lawrence really saw the laboratory blackboard with the words "supporting the Spanish Civil War rally", but Oppenheimer was not there at the time, and Lawrence, who was furious, took the blackboard eraser and wiped it off on the spot.

Lawrence in the movie, Image source: Still from the movie "Oppenheimer"

In fact, Lawrence himself was not a noble scientist who stayed away from politics. It was just that his political activities focused on school policies and funding. He was one of the best money-making scientists among his peers, and because of this, he did some dishonest things. He once hired Italian physicist and discoverer of neptunium Segrè with a monthly salary of $300, but when he learned that Segrè could not return to Italy and had to stay in the United States because of Mussolini's policies, he reduced his monthly salary to $116 .

However, when the University of California wanted to fire Segrè because of his nationality, Lawrence found a way to keep him by changing his position. Later, he used the same method to retain his student, Chinese female physicist Wu Jianxiong , and let her participate in the Manhattan Project.

10 The Real Leader of the Manhattan Project

Strictly speaking, Oppenheimer was not the leader of the Manhattan Project, but only the leader of Los Alamos National Laboratory. Los Alamos National Laboratory was responsible for designing the atomic bomb itself. In addition to this laboratory, the Manhattan Project also had many other locations such as the University of Chicago, Hanford, Oak Ridge (headquartered in Oak Ridge), each responsible for other links in the entire process of atomic bomb production.

If the Manhattan Project itself had a leader, yes, it was General Groves . From site selection to construction to material procurement to intelligence, he was the overall coordinator of the entire project. Even the name of the Manhattan Project was given by him.

General Groves in the movie. Image source: Still from the movie "Oppenheimer"

The choice of Oppenheimer as the head of Los Alamos National Laboratory was also controversial at the time. Oppenheimer had little administrative experience, had never won a Nobel Prize, and often participated in left-wing activities. But Groves firmly believed that the task of establishing a laboratory in a remote area required a person with a broad knowledge that no other physicist could match ; and Oppenheimer had a "vain ambition", which Groves believed was exactly the motivation needed to pursue the success of the project.

11The delivery address "exposed" the plan

When Groves found Oppenheimer, Oppenheimer claimed that every physicist knew what the Manhattan Project was. This statement was of course an exaggeration, but historically, as the Manhattan Project unfolded, many people did catch clues.

Feynman once said that the stationmaster at Princeton Railway Station probably knew something - the project team was worried that too many teachers and students buying one-way tickets from the small Princeton station would arouse suspicion, so they boarded the train from different stations, but all the equipment departed from Princeton Station. As a result, when he went to take the train, the stationmaster said to him, "So all these goods are yours!"

Another famous urban legend is that John Campbell, the editor of Astounding Science Fiction magazine at the time, found that his physicist subscribers had changed their addresses to New Mexico, so he inferred that there was some big project going on there. It is difficult to verify whether this legend is true or not, but in 1944, Astounding Science Fiction did publish a novel called "Dead Line", which described some content about the atomic bomb that surprised the researchers at Los Alamos National Laboratory, causing the FBI to suspect that someone had leaked the information and launched an investigation.

A female scientist who participated in the Manhattan Project later settled in China and took the Chinese name "Han Chun". She was at the University of Wisconsin at the time and had long wondered why the Van de Graaff accelerator at the university evaporated overnight, and even the physicists who used it disappeared soon after. Later, she received a job offer that only said it was related to the New Mexico War, and there was basically no other information. But when she ran to the library to borrow books about New Mexico, she found that the names of her missing colleagues all appeared on the library card, and she immediately understood what was going on.

12The world's first nuclear reactor was built in a stadium

Perhaps the most respected nuclear physicist in the United States during the war was Enrico Fermi. Fermi was Italian and won the 1938 Nobel Prize for discovering that bombarding atoms with neutrons could induce radioactivity, a discovery that was far more important to the atomic bomb than Einstein's mass-energy equation E=mc^2. He moved to the United States because of Mussolini's anti-Semitic policies and built the first nuclear reactor in history (a man-made sustainable chain reaction) in Chicago - Chicago Pile 1 .

Sketch of Chicago Pile 1. Image source: Wikipedia

In the movie, the nuclear reactor was placed in the basement of the University of Chicago Stadium, which is in line with historical facts. According to common sense, it seems very strange that such an important and confidential project was carried out in a place like a university stadium where people come and go, but there is actually an interesting historical coincidence behind it:

The University of Chicago was once a strong school in American football in its early years, and the stadium was built for this purpose, but later its strength declined and it welcomed a president who felt that college students' enthusiasm for sports was contrary to the academic spirit, so the team was disbanded at the end of 1939 and the stadium was idle. The nuclear reactor was originally planned to be built at another location, but the construction schedule there was delayed due to a strike, so the vacant stadium basement was used.

13 Women Scientists Who Worked on the Manhattan Project

Many female and minority scientists participated in the Manhattan Project, but only one person was mentioned by name in the movie, Lily Honig , who came to Los Alamos National Laboratory with her husband.

In the movie, she was asked if she could type. In history, she was indeed asked to take a typing test at the beginning, but she was soon assigned to the uranium chemistry project team. Later, the upper management felt that the radiation from uranium chemistry was too dangerous for women, so they transferred her to the explosive lens group where her husband was (in the movie, she mocked and said, "Your reproductive system is more exposed than mine." This refers to this matter). So when Kistyakowski was testing the atomic bomb detonation device, Lily also followed Oppenheimer and Groves to watch it - this was her project.

The so-called dynamite lens is the strange polyhedron that appears several times in the middle of the movie and needs to be pieced together. It is called dynamite because it is made of explosives, and it is called a lens because the purpose of these explosives is to focus all the energy of the explosion to the right place to detonate the atomic bomb, just like a lens can focus sunlight to a point.

The picture is taken from the promotional video of "Oppenheimer"

14How was the atomic bomb detonated?

The raw materials of atomic bombs are all naturally radioactive materials, which slowly release neutrons. Some neutrons will fly away directly, but others will hit other nearby atoms, breaking them apart (this is called fission), further producing more neutrons. Because naturally radioactive materials are too scattered, most of the neutrons will fly away, and the number of neutrons that can break other atoms is too small, so this reaction is unsustainable.

When the raw materials of an atomic bomb gather together, more and more neutrons will hit other atoms and further produce neutrons. When a new neutron is produced for every neutron consumed, it reaches the critical state. Many fictional works use the word "critical" to mean "the reactor is about to explode", but in fact the critical state is the state of normal operation of a nuclear reactor.

Nuclear weapons are not about criticality, but supercriticality : each neutron consumed produces more than one, and the reaction is getting faster and faster. Unfortunately, supercriticality alone is not enough to be used as a bomb. Nuclear reactions will release a lot of heat, which can easily blow up the raw materials that have not yet reacted, causing the reaction to abort. The result is enough to destroy several laboratories, but it is not enough to be used as an ultimate weapon.

The core problem that Los Alamos National Laboratory needs to solve is:

• First, how to make the originally scattered nuclear materials gather together at the moment of receiving the command, and change from subcritical to supercritical ;
• Second, how to consume all the consumable raw materials and complete all the fissions that can be carried out before the supercritical atomic bomb blows itself apart, thus releasing as much energy as possible .

There were two options under consideration: a gun-type method , where one piece of material is shot into another like a bullet; and an implosion method , where a ring of explosives explodes around it to create an explosive lens and squeeze the material to the desired density. Neither method can react all of the material for the atomic bomb, and the actual amount that can react is uncertain (which is why there are bets on the power of nuclear tests). The "Trinity Test" (the nuclear test in the film, referred to as the "Trinity Test") and the Fat Man bomb used implosion, while the Little Boy bomb used a gun-type method. Several other detonation methods were developed after the war.

15Will an atomic bomb ignite the atmosphere?

Discussions did occur about whether the atomic bomb would cause an atmospheric detonation.

In 1942, Taylor calculated that the explosion temperature of an atomic bomb would exceed that of the sun and could cause nuclear fusion in the atmosphere. Some physicists immediately thought that he had made a mistake, but many people still had doubts. In order to confirm whether this calculation was correct, Oppenheimer did go to someone - but the person he found was not Einstein, but Arthur Compton, the director of the Chicago group and Nobel Prize winner. Oppenheimer and Einstein did know each other, but the two conversations in the film were all fictional.

Stills from the movie Oppenheimer

The Manhattan Project eventually produced a secret report stating that this scenario was unlikely to occur , but some scientists were still concerned that the probability of "igniting the atmosphere" was not zero. Compton himself had always had doubts in his mind. Harvard President and chemist Conant said that when he saw the flash of the Trinity test explosion was much brighter and longer than expected, he really thought for a moment that the atmosphere had been ignited by them.

Later, this secret report was proven to be correct, otherwise we would not be here.

But mistakes do happen from time to time in nuclear weapons research, and occasionally with serious consequences. For example, on March 1, 1954, the hydrogen bomb code-named "Bravo" was tested. The yield was originally thought to be 5 million tons, but it was actually 14.8 million tons, causing many civilians who were thought to be in a safe area to be exposed to radiation. This was because the researchers originally thought that lithium 7 was inert, but it actually reacted at the temperature of the hydrogen bomb.

16Does the physicist’s bet really exist?

In the film, Fermi opened a betting table before the "Trinity Nuclear Test" and asked the scientists present to bet on the explosive equivalent of the nuclear test. This betting table also existed in history, but it was not opened by Fermi.

In the gambling game in history, Taylor was the most optimistic, betting on the largest equivalent of 45,000 tons, so when he went to watch the nuclear test, he wore gloves, sunglasses and sunscreen (unlike in the movie, he wore uniformly distributed welding goggles on top of his sunglasses). Oppenheimer himself chose the second-to-last pessimistic option of 300 tons. Rabi came late, and when he arrived, only 18,000 tons was left. In the end, he won (the official calculation at the time was 18,600 tons, and later recalculated it to be around 25,000 tons, both of which were the closest to him).

Stills from the movie Oppenheimer

Although Fermi did not make this bet, he made another bet - whether the atmosphere would actually ignite, and if so, whether it would destroy the entire state or the entire earth. Several guards were frightened by his bet and applied for leave.

What the film didn't show was another famous thing Fermi did during the nuclear explosion: he threw some pieces of paper into the air to see how far the shock wave of the explosion blew them away to estimate the equivalent of the atomic bomb. This is an example of the so-called Fermi estimate: using a very simple method to estimate the order of magnitude of a complex problem. Fermi's result at the time was 10,000 tons, which was very good for an estimate, but still slightly insufficient for a bet - if it was really 10,000 tons, the winner of the bet should have chosen Hans Bethe, who chose 8,000 tons.

17 The Goof Shot of the Countdown

There was a countdown clock next to the scene where Kistiakowski was about to press the button to stop it, made using a set of Nixie tubes.

The picture is taken from the promotional video of "Oppenheimer"

But in fact, the digital tube was not invented until 1955, so the Manhattan Project did not have the opportunity to use it. The one used in the movie seems to be the Soviet-made IN-14, which was not available until the 1970s.

18 Did Nolan really detonate an atomic bomb?

By now, many people know that Nolan claimed that CG is not needed for shooting nuclear explosions, so there is a joke that he detonated an atomic bomb to shoot the "Trinity Nuclear Test". In fact, mushroom clouds are not unique to atomic bombs, but are caused by atmospheric effects. As long as the explosion in the atmosphere is large enough, mushroom clouds can be produced. But it is indeed not easy to create mushroom cloud effects with non-nuclear explosives. In fact, this scene uses a variety of different explosive materials to detonate separately and then superimpose them to artificially create the visual effect of mushroom clouds.

Movie poster of Oppenheimer

19 The atomic bomb nearly sank into the ocean

The atomic bomb did not actually leave Los Alamos on a truck, that would have been too dangerous. The mechanical parts and nuclear materials for the atomic bomb were shipped to Tinian in batches and then assembled into the atomic bomb on the island. The raw materials for "Little Boy" were transported by the Indonesian heavy cruiser Annapolis, which was discovered and sunk by a Japanese submarine when it left Tinian. The U.S. Navy learned of its sinking four days later, and hundreds of sailors died from sun exposure, dehydration and shark attacks due to lack of rescue, which became a major scandal at the end of the war. I wonder how history would have been rewritten if the ship had been sunk while transporting the raw materials for the atomic bomb.

20 Feynman, the “drummer without a name”

Physicist Richard Feynman appears several times throughout the film, but he rarely speaks and no one calls him by name. How do we know it's him? Because he brings his tambourine with him almost every time he appears. Photos of Feynman playing the tambourine often appear in books about him and are well known, so people who know him know it's him at a glance.

Richard Feynman in the real world, image source: ysfine.com

Feynman taught himself to play drums in Los Alamos. In his autobiography, he said it was too boring to watch movies there. But there was a school here (the movie also mentioned the school), and there were a few drums in the school, so he played them for fun. But at that time, he didn't play the bongos in the famous photo later. He learned to play bongos after the war.

21 Cross out Kyoto, not because of honeymoon

After the success of the Trinity test, it was necessary to decide on the target city for dropping the atomic bomb on Japan. Nolan's script originally had the Secretary of War simply cross Kyoto off the list, but actor James Remar told him that one of the reasons the Secretary excluded Kyoto was because he had spent his honeymoon in Kyoto, so this part of the play was added. Unfortunately, Remar was wrong, and historians have found no evidence that he and his wife had ever been to Kyoto. According to historical records, he really only crossed out Kyoto because of its historical and cultural value .

22 V2 Rockets and airplanes?

When Borden described to Oppenheimer the scene of the Nazi V2 rockets he saw as a pilot, the screen showed a series of V2 rockets slowly overtaking the aircraft. In fact, the cruising altitude of the V2 rocket was several times that of the aircraft in World War II, and the speed was also several times, and it would not launch so many at a time, so this scene was either Borden's exaggeration or Oppenheimer's misunderstanding. If V2 was replaced with V1, it would be much more credible.

23 On Oppenheimer's Rehabilitation

Oppenheimer was not truly vindicated until December 16, 2022, when the trial that disbarred him was found to be unjust. Although there were some moves in the 1960s that amounted to a rehabilitation of his reputation, the trial itself was not mentioned, including the scene at the end of the film where he receives the Fermi Award. Fermi himself died in 1954, and the US government established the award in his name in 1956. The film shows him reconciling with Lawrence and Taylor and others when he receives the award, but historically Lawrence had been dead for several years at that time.

Planning and production

Author: Fang Gang, a popular science writer

Review丨Wang Hongpeng, Associate Researcher, China Science and Technology Museum

Planning丨Xu Lai

Editor: Cui Yinghao