Felix Bloch

Felix Bloch, a young Swiss physicist, is presented through two brief but telling observations of J. Robert Oppenheimer. First, a visit to Oppenheimer’s apartment in Zurich drew him into an impassioned conversation about America; later, Bloch reported that Oppenheimer no longer praised the Soviet Union so loudly. Together, the episodes make Bloch a witness to both a strong national attachment and a change in Oppenheimer’s political expression.

Identity and Encounters

Bloch enters the account as a young physicist who stopped by Oppenheimer’s apartment in Zurich. The book offers no extended biography of Bloch or detailed account of their relationship, but these encounters place him within Oppenheimer’s circle of scientific colleagues and show him attentive to the character revealed in everyday conversation.

The Navajo Rug and America

During the apartment visit, Bloch admired a beautiful Navajo rug that Oppenheimer had slung over his sofa. The object prompted a long, animated discourse on the merits of America. Bloch came away with no doubt about the intensity of Oppenheimer’s affection for his country, an attachment he described as especially apparent in that moment. The scene’s significance lies in its contrast: Oppenheimer was working hard on the difficult calculation of how stellar surfaces absorbed their internal radiation, yet among friends he tended to conceal such labor beneath an air of easy nonchalance and became animated when the subject turned to America.

A Later Political Observation

In November 1938, Bloch wrote to Isidor Isaac Rabi with greetings from Oppenheimer and remarked that Oppenheimer no longer praised the Soviet Union so loudly, calling this progress. The observation belongs to a period when friends had noticed that Oppenheimer was less loquacious about his political views, even as he continued to discuss politics privately with close associates. Bloch’s brief letter records a visible change in what Oppenheimer chose to say openly; set beside the Zurich conversation, it also distinguishes his pronounced affection for America from his increasingly restrained praise of the Soviet Union.