The trademarks that made Oppenheimer, Oppenheimer

April 20, 2020

J. Robert Oppenheimer’s hat is seen here in 1946 resting on cyclotron pipes. Oppenheimer frequently wore this hat, the style of which known as porkpie.

By National Security Research Center staff

J. Robert Oppenheimer will forever be known as the father of the atomic bomb, but he has some less-scientific attributes that have become quintessential.

On what would’ve been his 116th birthday on April 22, we’re remembering a few of those distinctive trademarks.  

His hat

Oppenheimer often wore his brown hat (size 6 and 7/8, according to The New York Times) whether he was in Los Alamos, Washington, D.C., or Princeton, New Jersey.

Known as a porkpie hat, this style was most popular through the mid-1940s.


Oppenheimer smoked for most of his life and died in 1967 from throat cancer at the age of 62. 

One of Oppenheimer’s physics students in the late ‘30s at the University of California — Berkeley, Edward Gerjuoy, recalled that “the most distinctive feature of his lectures [was] his chain smoking. He spoke quite rapidly, and puffed equally rapidly. When one cigarette burned down to a fragment he no longer could hold, he extinguished it and lit another almost in a single motion.”

J. Robert Oppenheimer’s chair will soon be displayed in the National Security Research Center, the Lab’s classified library located in the National Security Sciences Building. The NSRC contains tens of millions of materials related to our nuclear history.


During the Manhattan Project era, Oppenheimer was known for hosting parties and informal gatherings at his Los Alamos home. He was often the center of attention — and making his signature drink.

Oppenheimer’s martini recipe was four ounces of gin and a dash of vermouth; the rim of the chilled glass was dipped in honey and lime juice. 

Pat Sherr, the wife of a Lab physicist, said, “He served the most delicious and coldest martinis.”

J. Robert Oppenheimer frequently hosted gatherings at his Los Alamos home, where he charmed guests with his stories and made his favorite version of a martini.

His charm

Beyond his scientific genius, Oppenheimer’s charm is widely noted. From the twinkle in his bright blue eyes to his witty remarks, Oppenheimer was said to always remember a name and never forget a face.

This charm coupled with his intelligence were perhaps what led to the respect and loyalty many had for Oppenheimer.

Scientist Robert Christy remembered when Oppenheimer asked Christy to join him at the secret Los Alamos Lab. “I said I would be delighted because like most of his students, I would more or less follow him to the ends of the earth.”