Did Oppenheimer quote the Bhagavad Gita after the Trinity test?

Question

There is an often repeated story that Robert Oppenheimer, one of the leaders of the Manhattan Project, quoted the Bhagavad Gita after witnessing the first nuclear test.

One version of the story is told here:

Robert Oppenheimer, the scientist who directed the Manhattan Project that built the two atomic bombs dropped on Hiroshima and Nagasaki in August 1945, remained morally ambivalent about his role in the entire matter. He summed up the effect the first experimental test, code named Trinity, of an atom bomb had on him; he said, “Now I am become Death, the destroyer of worlds”, a rough translation of a verse from the Hindu scripture, the Bhagavad Gita.

I recently saw this tweet claiming he did not (the tweet is a photo but the source is from the letters pages of the London Review of Books) in 2018 and, in full, says:

Thomas Jones repeats the story that Robert Oppenheimer quoted the Bhagavad Gita after witnessing the first successful nuclear weapons test in New Mexico: ‘I am become Death, destroyer of worlds.’ I once had the chance to ask his brother, Frank, who was standing next to him at the time, what Oppie’s actual words were. Frank’s recollection was that he said: ‘I guess it worked.’

Jeremy Bernstein New York

So did he say the quote after the test?

Answer 1

No.

In the 1965 documentary "The Decision to Drop the Bomb", Oppenheimer described the moments after the bomb's explosion:

We knew the world would not be the same. A few people laughed, a few people cried. Most people were silent. I remembered the line from the Hindu scripture, the Bhagavad Gita; Vishnu is trying to persuade the Prince that he should do his duty and, to impress him, takes on his multi-armed form and says, 'Now I am become Death, the destroyer of worlds.' I suppose we all thought that, one way or another.

In the book Brighter Than a Thousand Suns: A Personal History of the Atomic Scientists, written based on first-hand interviews with the Manhattan Project scientists and others, it is noted that Oppenheimer initially recalled (but again, did not say) a different quote from the Bhagavad Gita, before recalling the famous "destroyer of worlds" quote:

If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one...

Both sources agree that Oppenheimer remembered the quote, but didn't actually say it out loud.