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”). 

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”).

Robert Serber 

Robert Serber (1909-1997) was a postdoctoral fellow at the University of Michigan in 1934 when he attended a guest lecture by Oppenheimer. The professor’s brilliance was so unforgettable, Serber packed his bags and transferred immediately to UC Berkeley to study under him. The two became fast, lifelong friends. When Serber was ready for an associate professorship, Oppenheimer advocated for him. Department chair Raymond Birge, however, wrote that “one Jew in the department is enough.” (Oppenheimer was Jewish, as was Serber.)

Serber accompanied Oppenheimer to Los Alamos and was later one of the first Americans to inspect the bomb sites at Hiroshima and Nagasaki. He is played by Michael Angarano (“I’m Dying Up Here,” “The Knick”).

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”).