New Books Network Podcast: Jeremy Bernstein on Oppenheimer, Nuclear Weapons, and Proliferation

Episode Date: December 10, 2025
Guest: Jeremy Bernstein (archived 2007 lecture)
Host: New Books
Episode Theme: Exploring the life and legacy of J. Robert Oppenheimer, stories from the dawn of the atomic age, the technicalities and ethics of nuclear weapons, and the realities of global proliferation.

Overview

This episode features the late physicist and writer Jeremy Bernstein, revisiting a 2007 lecture on J. Robert Oppenheimer, the Manhattan Project, and the rise of nuclear arms. Bernstein, who was both a contemporary and a chronicler of many nuclear-age figures, shares insights from his personal interactions, technical explanations of nuclear weapon-making, and reflections on proliferation, enriched with anecdotes and memorable humor.

Key Discussion Points & Insights

1. Oppenheimer’s Genius and Los Alamos Culture

• Bernstein starts by debunking the myth that Los Alamos was overflowing with Nobel Prize winners; at the time, only three or four laureates were present, but many future recipients worked there (02:45).
• On Oppenheimer’s intellect:
  • “Oppenheimer was intellectually superior to everybody. He had the capacity of making instantaneous understanding of things... he had everything in his head.” (03:43, paraphrasing Hans Bethe)
• Anecdotes about Oppenheimer:
  • The “Added Cubit” lecture and the biblical reference to Matthew 6:27 (05:23).
  • Bernstein’s humorous exchange with Oppenheimer about the lecture title, with Oppenheimer noting Bernstein's rabbinical lineage (05:31).
  • Oppenheimer’s reaction at the Trinity test: “It worked and God did it work.” (07:06, Oppenheimer, as relayed by Frank Oppenheimer)

2. The Spread of Nuclear Weapons - A Satirical Song

• Interlude with Tom Lehrer’s song “Who’s Next?” satirizing the global spread of the bomb (08:30–09:32), underscoring the inherent absurdity and danger in nuclear proliferation.

3. The South African Nuclear Program: Lessons in Proliferation

• Key technical explanation: The difference between “fissionable” and “fissile” material, emphasizing the difficulty of enriching uranium to weapons-grade (11:11).
• South Africa uniquely built gun-type uranium bombs, making enough for six weapons before abandoning (12:04).
• On dismantling:
  • The process took four years, and uranium was partially repurposed for medical reactors, the rest placed under international supervision (13:30).
  • Notable involvement of A.Q. Khan, the Pakistani scientist who “opened a supermarket for selling nuclear material” (14:50).

4. Bernstein’s Personal Experience at Nuclear Weapons Tests

• Summer 1957 at Los Alamos: Bernstein receives “Q” clearance, reflecting on the oddities of security measures (16:08).
• At the Nevada Test Site:
  • Vivid recounting of witnessing a nuclear explosion:
    • “When I counted 10 and turned around, I saw a sight which can't get out of your mind... a livid fireball rising with colors of orange, red. A terrible, awesome, monstrous thing.” (21:56)
  • On the aftermath and the shock wave: “The shockwave at Hiroshima was 250 miles an hour and knocked over all the cooking stoves, which is what caused the firestorm in Hiroshima.” (23:42)
  • Reflects on the health impact on soldiers present at test sites and the government’s casual attitude (24:52).

5. Inside the Bomb Assembly Area

• Bernstein describes entering a facility with dozens of plutonium pits:
  • “All of them lined up on shelves enough to destroy a continent. I was, I remember, pretty shocked... Carson, observing this performance, picked one off the shelf and handed it to me, saying, 'don't drop this.' So I was holding this plutonium pit, which is a little bit warm to the touch, about the size and weight of a bowling ball.” (26:32)
• Brief literary aside about the surreal, almost mundane work environment: a technician filing explosives, a woman knitting beside him—at first doubted by fact-checkers, but confirmed later (28:18).

Audience Q&A: Contemporary Proliferation, Iran, and Terror Threats

Iran’s Nuclear Ambitions

• On Iran’s enrichment efforts:
  • “I am quite certain that they’re working to get it... their cascade makes lightly enriched uranium... But once you have [4%], to go from 4% to 90% is much easier.” (29:22)
  • Notes Israel’s likely red lines: “I don’t think they'll let the Iranians have a weapon. I mean, look what they did in Syria a few weeks ago. They flattened what was presumably the beginning of a reactor.” (31:27)

Israel’s Nuclear Arsenal

• What is known (and unknown):
  • “They must have several hundred. I think they were self-produced. The French helped out in the beginning... They probably have boosted nuclear weapons.” (31:01)

Ease of Nuclear Weaponization

• On technical challenges:
  • “Making a crude weapon… the North Koreans tested the device and they got a half a kiloton. Now, everybody said, well, that's a crude weapon. Well, I like to think of it in terms of rider trucks... a 500 kiloton nuclear explosion is a very serious matter.” (32:47–33:59)
  • Uranium-based bombs described as “pretty straightforward to make a workable nuclear weapon.” (33:59)

Dirty Bombs and Terrorist Threats

• Clarifies what a “dirty bomb” is:
  • “What a dirty bomb is is that somebody goes into a hospital and gets a bunch of radioactive waste and sticks a high explosive around it... But that's not a nuclear weapon.” (37:32)
  • Suggests the main risk is from fissile material theft and states: “If a very well organized terrorist organization could buy the fissile material, then they could probably assemble it into a weapon.” (38:35)

State vs. Non-State Proliferation

• To build a “real” nuclear weapon requires a nation-state’s resources, but assembled bombs are plausible if fissile material is acquired illicitly (38:45–39:33).
• “There's a lot of this stuff floating around. I mean the Russians have tons and tons of fissile stuff. And how well is that guarded?” (39:33)

Proliferation Outlook

• Bernstein’s prediction for the next 50 years:
  • “In terms of proliferation, I think it's worrisome because a lot of crazy countries are now talking about getting nuclear weapons.” (36:32)
  • Finds North Korean partial disarmament encouraging, but is pessimistic overall, especially regarding Iran and the irrelevance of sanctions (36:32–37:32).

Memorable Quotes & Notable Moments

• On Oppenheimer:
  • “He was always the smartest boy in the class. And this lasted throughout his entire life.” (04:32)
• On witnessing a nuclear blast:
  • “A sight which can't get out of your mind. Current horizon was a livid fireball rising with colors of orange, red. A terrible, awesome, monstrous thing.” (21:56)
• On proliferation and ease of weapon-making:
  • “Making a crude weapon… it's pretty straightforward to make a workable nuclear weapon. And I don't think you have to have a lot of great technical skills.” (33:59)
• On Iran:
  • “They have to be stopped. Although I don't know how to do that. I think that the Israelis will do it.” (29:59)

Additional Insights and Ironies

• The “Plumbob” anecdote:
  • U.S. nuclear testers may have unintentionally launched the first human-made object into outer space—a manhole cover propelled by a test blast (41:28).
• The surreal juxtaposition:
  • Everyday life amid extinction-level tools: “This guy found this high explosion. She's knitting. It looked like a sweater... What a metaphor, man.” (28:21)

Timestamps for Key Segments

• Oppenheimer and Los Alamos: 02:45–07:14
• Tom Lehrer’s satirical nuclear song: 08:30–09:32
• The South African nuclear program explained: 09:59–14:50
• Bernstein’s experience at Los Alamos and test site: 16:04–26:32
• Nuclear test witness, blast description: 21:56
• Audience Q&A on proliferation, Iran, Israel, dirty bombs: 29:20–41:28
• Manhole cover in space; ending anecdote: 41:28–42:37

Tone and Style

Bernstein blends technical clarity, dry wit, and gentle self-deprecation, illuminating the moral complexity and persistent dangers posed by nuclear weapons:

“It's a very jolly way to end one of the most downrous of all the species. Thank you very much.” (42:37)

For listeners curious about the human stories behind nuclear arms, the psychology of scientists, and the ongoing challenges of global armament, this episode is a sobering, insightful, and surprisingly entertaining journey through history and technical detail.