Director Christopher Nolan assembled an all-star cast for his summer blockbuster “Oppenheimer,” a biopic about physicist J. Robert Oppenheimer and the creation of the Manhattan Project. The film, based in part on the definitive Oppenheimer biography “American Prometheus,” stars Cillian Murphy as the famed scientist.

Here is what the real people depicted in “Oppenheimer” actually looked like:

J. Robert Oppenheimer 

One of the 20th century’s great enigmas, J. Robert Oppenheimer (1904-1967) was born into a wealthy New York family. His pick as the head of the Manhattan Project was a risky one: He was a theoretical physicist, not a practical one, and he was well known for his eccentricities. But Oppenheimer transformed into a bureaucratic mastermind, deftly leading scientists and the military together at Los Alamos.

After the war, he was swept up in the nationwide panic over communism, and several key figures within the U.S. government accused him of being a Soviet spy. Some of his former colleagues turned on him in a 1954 hearing that would end in the revocation of his security clearance. After a lifelong habit of smoking up to five packs a day, Oppenheimer died of throat cancer in 1967. He is played by Cillian Murphy (“Peaky Blinders,” “Inception”) in “Oppenheimer.”

Kitty Oppenheimer 

Kitty Puening (1910-1972) was born in Germany and immigrated to the United States when she was a toddler. Described by friends and acquaintances as smart, mercurial and vivacious, Oppenheimer was her fourth husband. Her first marriage lasted just a year, and she soon became the common-law partner of Joseph Dallet Jr. a member of the Community Party. Bolstered by his convictions, Dallet left for Spain to fight in the Spanish Civil War. He died in combat in October 1937.

When Kitty met Oppenheimer at a party in Pasadena two years later, she was married to her third husband, Stewart Harrison. Kitty became pregnant with Oppenheimer’s child in 1940, and they asked Harrison to grant Kitty a divorce. The Oppenheimers had a son and daughter together. Kitty’s ties to the Communist Party were part of the evidence put forward by Oppenheimer’s detractors.

Kitty Oppenheimer is played by Emily Blunt (“A Quiet Place,” “Jungle Cruise”).

Jean Tatlock 

Described by some as the love of Oppenheimer’s life, Jean Tatlock (1914-1944) was a pioneering doctor in the Bay Area. She attended Stanford Medical School and became a clinical psychiatrist in her 20s. Her brilliance attracted Oppenheimer, who met her at a house party in Berkeley. The pair were on and off for years until Tatlock called their engagement off in 1939. 

Tatlock was found dead in her San Francisco apartment in 1944. She was just 29. You can read more about her fascinating life in our previous story. Tatlock is played by Florence Pugh (“Little Women,” “Midsommar”).

Ernest Lawrence

Long before Oppenheimer became a household name, Ernest Lawrence (1901-1958) was one of America’s most famous scientists. He joined the physics faculty at UC Berkeley in 1928 and, the next year, was joined there by Oppenheimer. Both in their 20s, they became close friends — Lawrence later named his son Robert in Oppie’s honor. While at Cal, Lawrence invented the cyclotron, which earned him a 1939 Nobel Prize.

However, their friendship soured, as the men butted heads about the future of nuclear weapons. After the war, Lawrence pushed for more government funding into nuclear research, and founded the Lawrence Livermore National Laboratory. The death knell for their friendship was when Lawrence reportedly discovered Oppenheimer was having an affair with Ruth Tolman, the wife of their friend and Caltech scientist Richard Tolman. 

The Lawrence Berkeley National Laboratory and the chemical element lawrencium are both named for Lawrence. He is played in the movie by Josh Hartnett (“Penny Dreadful,” “Pearl Harbor”). 

Lt. Gen. Leslie Groves

The military head of the Manhattan Project, Lt. Gen. Leslie Groves (1896-1970) was tasked with finding a scientist to lead the team in Los Alamos. Groves, who was the son of an Army chaplain, was the consummate military bureaucrat. His skill at building teams landed him in charge of both the construction of the Pentagon and the Manhattan Project during World War II.

On the day the bomb was dropped on Hiroshima, Groves called Oppenheimer from Washington to congratulate him. “I think one of the wisest things I ever did was when I selected the director of Los Alamos,” Groves said. When Oppenheimer said he wasn’t as sure, Groves replied, “Well, you know I’ve never concurred with those doubts.”

Groves is played by Matt Damon (“The Martian,” “The Last Duel”). 

Lewis Strauss

One of the villains of the Oppenheimer story is Lewis Strauss (1896-1974), the chair of the U.S. Atomic Energy Commission. Oppenheimer and Strauss conflicted in just about every way. While Strauss wanted the U.S. to maintain secrecy about their nuclear arsenal and develop ever more powerful hydrogen bombs, Oppenheimer objected to both. Oppenheimer, who was highly regarded and never afraid to embarrass someone he considered foolish, irritated Strauss constantly. 

Strauss got his revenge working with FBI director and professional paranoiac J. Edgar Hoover to look for Soviet sympathies in Oppenheimer’s life, which set into motion the security hearing that would revoke Oppenheimer’s top-secret clearance. Strauss is played by Robert Downey Jr. (“Iron Man,” “Dolittle”). 

Edward Teller

Edward Teller (1908-2003) was the brilliant, obstinate scientist who eventually earned the moniker “the father of the hydrogen bomb.” Born in Hungary, Teller was recruited for the theoretical physics division at Los Alamos. He became obsessed with the possibility of a hydrogen bomb, but other scientists believed the idea was a fantasy. Angry at this rejection and upset he was passed over as the director of the division, Teller refused to do the calculations he had been recruited for. 

In a note to Groves after Teller announced his one-man strike, Oppenheimer said Teller was “quite unsuited for this responsibility.” Ultimately, Oppenheimer believed Teller’s intellect was still more valuable kept within the walls of Los Alamos. He told Teller he could work on the hydrogen concept. During the Trinity test, Teller was one of the few men who disobeyed the orders to lie face down; instead, he watched the blast straight on while wearing protective eyewear.

After the war, Teller returned to Los Alamos when President Harry Truman approved the nation’s hydrogen bomb project. Teller was instrumental in the creation of the first H-bomb detonated at Enewetak Atoll in 1952. Teller also helped found the Lawrence Livermore National Laboratory with Ernest Lawrence and served as a physics professor at UC Berkeley. He died in Stanford, California, at the age of 95. Teller is played by Benny Safdie (“Licorice Pizza,” “Are You There God? It’s Me, Margaret”). 

Richard Feynman 

Few men involved with the Manhattan Project had lives as colorful as Richard Feynman (1918-1988). Feynman was not yet 25 when he was recruited to work in Los Alamos — he didn’t even have a graduate degree. But the Queens man with a thick New York accent and a devilish grin was an undeniable genius. He also loved pranks. He was known for sneaking into the facility — something that could have easily gotten him shot — and used to crack safe combinations where his colleagues stored top-secret material. 

In 1965, he won the Nobel Prize in Physics, and he became a household name thanks to his bestselling memoir “Surely You’re Joking, Mr. Feynman!” He is played by Jack Quaid (“The Boys,” “Logan Lucky”).

Isidor Rabi

Isidor Rabi (1898-1988) met young Robert Oppenheimer when the men were students in Leipzig. The two had much in common: They were both Jewish scientists who had grown up in New York, although Oppie was the son of privilege and Rabi had grown up in poverty. Along with being professional colleagues, they were close friends, and Rabi had a reputation for being one of the only people unafraid to challenge Oppie. 

Rabi was working at the Massachusetts Institute of Technology’s radiation lab when Oppenheimer asked him to be the deputy director of the Manhattan Project. Rabi turned him down, but he did agree to be a consultant, and he traveled to Los Alamos on occasion. Before the war was even over, Rabi won a Nobel Prize in physics; some of Rabi’s research was later used to create modern MRI machines.

Rabi and Oppie remained friends until Oppenheimer’s death. “We were friends until his last day,” Rabi said. “I enjoyed the things about him that some people disliked.”

He is played by David Krumholtz (“White House Plumbers,” “The Deuce”).

Werner Heisenberg

Oppenheimer’s counterpart in Nazi Germany was Werner Heisenberg (1901-1976). As the Manhattan Project was getting off the ground, American scientists feared they were far behind the Nazis’ nuclear program. Luckily for them, Heisenberg was nowhere near the creation of an atomic bomb. Despite being a Nobel Prize winner, Heisenberg never got close to unlocking nuclear fission; when he learned of Hiroshima while in an English prison camp, he expressed astonishment that the Americans could create such a weapon at all.

Heisenberg is played by Matthias Schweighofer (“Hinterland,” “Army of the Dead”). 

Frank Oppenheimer 

Frank Oppenheimer, the younger brother of Robert, also had his life torn apart by Cold War paranoia. A brilliant scientist in his own right, Frank Oppenheimer (1912-1985) joined the American Communist Party in the 1930s. Although he left it several years later, after the war he was ordered in front of the House Un-American Activities Committee. As a result of the Red Scare fervor, he was forced to resign his teaching job at the University of Minnesota. He moved to a cattle ranch in Colorado. There, he was able to get a job teaching again — at a high school. 

In the 1960s, Oppenheimer decided he wanted to open a kid-friendly science museum. He found its home in San Francisco, and there he opened the Exploratorium in 1969. He was a constant presence at the museum until his death in Sausalito in 1985. He is played by Dylan Arnold (“You,” “Halloween”).

Boris Pash

Boris Pash (1900-1995) was born in San Francisco to a highly religious family. His father, a Russian Orthodox priest, took teenage Pash with him to fight in Russia against the Bolsheviks in 1916. Pash fought there until 1920 and then returned home to the United States after it was clear the Bolsheviks had won the revolution. Pash joined the U.S. Army and was eventually appointed the chief of counterintelligence for the Ninth Corps stationed at the Presidio.  

In that role, he was ordered to investigate possible security breaches at the Berkeley radiation lab, which the government was increasingly worried had been compromised by Soviet spies. Pash interrogated Oppenheimer and was the person responsible for having Jean Tatlock’s phone bugged. Groves reassigned Pash to the Alsos Mission in Europe, which was the counterintelligence operation to determine how far along the Nazis’ nuclear program was. Pash is played by Casey Affleck (“Manchester by the Sea,” “Interstellar”).