UC Berkeley News


Libretto takes liberties with fundamental physics
Professor's technical concerns fall on deaf ears

| 22 September 2005

Berkeley physicist Marvin Cohen, by his own account only a "sporadic" operagoer, finds himself these days passionately interested in John Adams's Doctor Atomic — the opening lines of which, he says, misrepresent the physics of bomb making.

Marvin Cohen
Marvin Cohen

Cohen, head of the American Physical Society, is pleased that Doctor Atomic is about a complex — not mad — physicist. Still, he's unsatisfied with the chorus's first words: "Matter can neither be created nor destroyed, but only altered in form/Energy can be neither created nor destroyed, but only altered in form.")

Cohen first heard this declaration, set to music, at a discussion and sneak preview last fall at the San Francisco Opera, an event to which several physicists had been invited. When the demonstration ended, he recalls, "my hand flew up immediately. I noted that 2005 had been designated the World Year of Physics, celebrating the 100th anniversary of Einstein's year of great discoveries, including E=mc2." That formula shows that "matter can be changed into energy. Even more important, given the opera's theme, that's how you make an atomic bomb: You destroy a little bit of matter and turn it into a huge amount of energy."

The words in the libretto, Cohen emphasized, "are what science believed in the 19th century — and they're no longer considered to be true."

Leaving San Francisco that day, Cohen "just assumed" that composer John Adams and director/librettist Peter Sellars would change the offending lines. "I'm so used to being listened to," he shrugs. "It's one of the faults of the professor role."

Although San Francisco Opera administrators indicated that they understood his point, Sellers and Adams made no changes — and Cohen soon found himself reading the libretto in its entirety in search of a passage that set the physics straight. "The closest thing I found was a line near the end, in which a Manhattan project scientist refers to their work 'in the loss of mass.' "

Close, but no cigar. "By itself," he says, "those words are obscure and incomplete — because mass is not lost; it's just turned into energy. Mass and energy are different forms of the same 'thing,' which is conserved."

The frustrated physicist also reviewed government documents that Sellars had mined (along with lines from Baudelaire, Muriel Rukeyser, and the Bagavagita) to create the libretto. The offending lines in the opening, he found, come from a 1945 document, "Atomic Energy for Military Purposes," also known as the Smyth Report. What it goes on to say (and the libretto omits) is that the immutability of energy and matter, once a scientific axiom, has indeed been disproved: "It is now known…that matter can be converted into energy and energy into matter."

Sellers and Adams, though concerned with doing justice to the story of Oppenheimer and the bomb (Adams has called it "the Gotterdammerung of American culture"), were not to be persuaded, not even when Cohen, in his words, "dropped my own atomic bomb" — an extra phrase he suggested be slipped in, after the assertion that mass and energy are immutable: "But this is no longer true."

As a professor of condensed-matter theoretical physics, Cohen has argued hard for a Doctor Atomic tweak even though, as an amateur clarinetist, he's uneasy with his role in the matter of the libretto. "I've got a feeling for how artists feel," he says. There's the famous story, he recalls, of the emperor telling Mozart that his opera had too many notes, to which the composer retorted that, on the contrary, it had "just the right number of notes."

"I never thought I'd be on the other side," Cohen says. "I always identified with Mozart."