Capítulo 4
From Cosmic Rays to Blacklists
After the war, Frank eagerly returned to physics research, joining the University of Minnesota in 1947 to study cosmic rays. Using giant helium balloons developed by General Mills, Frank built cloud chambers to detect these mysterious particles from space. In a significant discovery, Frank found evidence that cosmic rays contained nuclei of all elements, not just protons as previously thought. This suggested they might originate from exploding stars-the stellar furnaces that created complex elements. Physicist and Nobel laureate Hans Bethe later praised Frank's "experimental ingenuity" and the new techniques he invented.
Frank's cosmic ray experiments led to remarkable adventures. During one expedition, he convinced the U.S. Navy to let his team use the USS Saipan aircraft carrier. After launching a balloon that came down in remote Cuban terrain, Frank and colleagues embarked on a twelve-mile trek through difficult landscape to retrieve their equipment. What began as a small group of physicists grew into a procession of thirty-three as local Cubans joined to help, offering machetes and guidance through steep canyons and slippery ridges.
While Frank was happily pursuing research and teaching, the FBI was tracking his every move. They had files on him dating back to 1941, noting his "alias" Frank Folsom. Though Frank hadn't been involved with the Communist Party since 1940, his advocacy for civilian control of atomic energy and opposition to military control made him suspect. When Frank received an invitation to lecture at Sweden's Royal Institute of Technology, the State Department refused to renew his passport.
Frank made a devastating error that would end his career when he lied about his Communist Party membership. After a Washington Times-Herald reporter called him about a forthcoming expose identifying him as "a card-carrying member of the Communist Party who worked on the Manhattan Project," Frank initially denied everything in anger and fear. The irony wasn't lost on him-he had recently written a paper about how lying was the worst thing anyone could do.
On June 3, 1949, Frank and Jackie received a summons to appear before the House Un-American Activities Committee. Knowing he'd have to tell the truth, Frank visited J.W. Buchta, head of the Minnesota physics department, and admitted his lie about Communist Party membership. He offered a letter of resignation as a courtesy, with the understanding it wouldn't be acted upon. However, while Frank was in Washington testifying, the University of Minnesota accepted his resignation.
When Frank and Jackie arrived in Washington for the hearing on June 14, 1949, Frank was accompanied by lawyer Clifford Durr while Jackie waited outside. Committee member Richard Nixon was present. Frank was questioned about his Communist Party membership numbers and repeatedly asked about the political affiliations of his associates. Frank consistently refused to discuss others' politics, stating: "I believe they have to be questioned on those themselves." A supportive letter from Major General Leslie Groves was read into the record, praising Frank's "indispensable" work on uranium isotope separation during atomic bomb development.
Despite being fired from Minnesota, Frank tried persistently to find another physics position. He'd hear that departments wanted him, only to receive rejection letters weeks later. Eventually, an FBI agent revealed the truth directly: "Well, don't you want an academic job? You have to cooperate." Unable to work in America, Frank received an offer from the Tata Institute in Bombay but was denied a passport.
Capítulo 5
The Rancher-Teacher
After being blacklisted from physics, Frank and his family retreated to a cabin in Blanco Basin, Colorado-a stark transition for the Jewish intellectual from Manhattan. Frank had discovered the property during a horseback ride with Bob Wilson in 1948 and purchased it as a summer place, never expecting it would become their permanent home. Despite missing physics terribly, Frank embraced ranching with characteristic determination.
The Oppenheimers were complete outsiders in rural Colorado. With only 3,000 people in the entire county and just five other families in Blanco Basin, the locals viewed them as aliens. Living at 8,000 feet on beautiful land "like the Swiss Alps," they struggled with harsh conditions-no electricity, minimal amenities, and winters where snow could last from October through April, six feet deep in places.
Frank and Jackie gradually taught themselves ranching through books and neighbors' advice. Despite their isolation, Frank remembered the ranch years primarily as "a wonderful time," though Jackie found it much harder-raising small children while tending cattle and dealing with Frank's volatile temperament. Their children, Michael and Judy, attended a one-room schoolhouse with sometimes just themselves as students. Frank helped build the "teacherage" and found them a teacher.
The FBI continued to harass Frank on the ranch, making regular visits that became so familiar that Mike and Judy came to recognize the agents. When the agents would call ahead to check road conditions, Jackie once declared, "I'll be damned if I'll feed them," though Frank eventually weakened and offered them hard-boiled eggs-prompting Mike to nickname them "the hard-boiled eggs" whenever he saw them approaching.
When a teaching position opened at Pagosa Springs High School, Frank seemed a natural fit, though he initially couldn't get hired for suspected political reasons. After overcoming credential hurdles, he began teaching general science, biology, chemistry, and physics to about a hundred students in 1957-introducing the school's first-ever physics course.
In this community of 850 people who worked mainly on ranches, Frank must have seemed like he "dropped in from Mars," as former student Stanley Fowler put it. Unlike other ranchers in overalls, Frank wore a tie (which he used to clean the blackboard), twitched and paced during lectures, and disappeared into storage rooms for cigarette breaks. Understanding his students' initial disinterest in science, he devised ingenious experiments to capture their attention-taking them to junkyards to disassemble carburetors and distributors, conducting dissections, and making abstract concepts tangible.
Frank's impact was transformative. His students began winning science fairs in Durango and at the state level. At one Colorado-Wyoming science fair, judge Albert Bartlett recalled most prizes going to Pagosa Springs students-many Hispanic and from "ordinary origins"-leaving Denver-area students stunned. As Frank's graduates entered college, word of their exceptional preparation spread.
In summer 1958, Frank moved the family to Boulder, partly to explore teaching opportunities at the University of Colorado. He helped develop the Physical Science Study Committee Physics Course as part of America's post-Sputnik response. His experiments made physics "come alive in the hands of students," according to David Hawkins. His students were devoted, including future Nobel laureate James Heckman, who still treasured his lab book forty-five years later, saying "We devoured the physics and we devoured the man."
Capítulo 6
A Library of Experiments
Frank thrived on teaching but had an ulterior motive: he hoped his work would help him gain entry to the University of Colorado. More than anything, he wanted to return to physics-designing experiments, tinkering with equipment, and making discoveries. His strategy worked, and he was offered a position as a research associate in 1959.
By 1961, Frank had sold parts of the ranch that needed constant attention and moved his family to Boulder. When he went up for tenure, anti-Communist members of the Board of Regents tried to block his appointment, but with support from department chair Wesley Brittin and letters from eminent physicists like Hans Bethe, George Gamow, and Victor Weisskopf, Frank was hired as associate professor in 1961 and became full professor in 1964.
Frank plunged back into research on elementary particles, putting together a "users' group" that studied particle tracks at Lawrence Berkeley Laboratory. His work attracted nearly a million dollars in grants. But physics had changed dramatically since the war. Once a haven for eccentric intellectuals who mixed art and philosophy with science, physics had become a high-status, conformist occupation focused on material gain.
As soon as Frank returned from his mountain exile, he began speaking out against the Vietnam War. He wrote letters to newspapers and Congress, urging alternatives to war and thanking Senator William Fulbright for his "courageous and wise" stand. Though Vietnam wasn't a nuclear war, Frank argued it was still very much a war "in the shadow of the H-bomb," with America's nuclear arsenal always available as a fallback.
At the University of Colorado, Frank transformed the introductory physics lab into a permanent "Library of Experiments" with over eighty demonstrations always available to students. Using mundane objects combined with sophisticated measuring equipment, he built ingenious demonstrations of physical principles.
Frank insisted on not having a lab manual because he thought it would be too confining. Instead, he worked with students one-on-one, encouraging questions. His enthusiasm was contagious, and he took pleasure in getting others to see interesting things in his demonstrations. When the University obtained funds for new laboratories, Frank designed large open spaces with inexpensive movable tables where students could see what others were doing.
Though his methods won national recognition with other universities calling regularly to learn about the lab, after Frank left Boulder, the "Library" didn't survive for long. But it wasn't the end-it was just the beginning. Frank was already thinking about bringing such a "library" to much larger audiences, believing it couldn't be done in an academic setting. In 1965, he received a Guggenheim fellowship and used it to visit science museums in Europe.
Capítulo 7
The Birth of the Exploratorium
Frank moved to San Francisco in 1967 with Jackie, determined to create his "woods of natural phenomena"-a place where people could reconnect with the physical world. He wrote a detailed "Rationale for a Science Museum," explaining that teaching science without props was like explaining swimming without letting a person near water. Students had become dangerously removed from their surroundings, with little experience of the natural world to build intuition.
In 1968, Frank discovered the Palace of Fine Arts-Bernard Maybeck's pseudo-Roman ruin from the 1915 Panama-Pacific Exposition that had just completed restoration. Despite being a stranger competing with local groups who wanted the space, Frank charmed his way into the right circles, winning over Scott Newhall (the Chronicle's editor) and his wife Ruth, who arranged meetings with Mayor Joseph Alioto and city supervisors.
By December 1968, Frank formed a nonprofit board including old friends like Wolfgang Panofsky and Nobel laureate Luis Alvarez. By May 1969, he secured a dollar-a-year lease on the Palace. The Exploratorium got put together like an old-fashioned barn raising, with Panofsky loaning pieces of an accelerator and helping scrounge materials from Stanford. "We both agreed that physics was grubby," Panofsky said, "and it shouldn't be pretty and under glass."
With $50,000 from the San Francisco Foundation, Frank, Jackie, and their son Mike began transforming the space. They coined the name "Exploratorium" because "museum" seemed too static. In late August, Frank simply opened the doors without an announcement. "We just watched what happened," he said. People started wandering in.
Frank compensated for his limited budget by doing everything cheaply, using all he'd learned from his years of experimenting, ranching, and teaching. The museum became a "weave" that knit the threads of Frank's life together, with early exhibits coming from every imaginable source. The acquisition process was "opportunistic" like biological evolution-some exhibits went extinct immediately, while others endured, like the "Touch the Spring" exhibit from Lockheed and the Abe Lincoln portrait from Bell Labs.
The most important early exhibit was the shop, located right next to the entrance. Frank insisted it remain visible, believing visitors should see and smell the creation process. Exhibits were built pragmatically robust-"Jeeps rather than Ferraris"-designed to withstand punishment but also to demonstrate natural limits. When staff tried to make exhibits unbreakable, Frank would say, "Let them break it. They learn something from that."
Capítulo 8
Art and Science: Two Sides of the Same Coin
Frank believed art and science were inseparable at the Exploratorium. As he put it, "One cannot truly understand nature without also discovering the ways in which it is related to human experience and feeling." The museum quickly became a magnet for artists, who brought installations that blurred the line between art and scientific demonstration.
Bob Miller, an artist experimenting with prisms and mirrors in a dingy North Beach apartment, was invited by Frank to bring his work to the Exploratorium. The result was the "Sun Painting"-a spectacular palette of pure colors extracted from sunlight that created otherworldly landscapes at the museum's entrance. True to the Exploratorium's philosophy of honesty, the sculpture only came alive when actual sunlight broke through San Francisco's fog-sometimes requiring endless patience from visitors, making the experience, as poet Muriel Rukeyser put it, "a good deal like real life."
The Exploratorium became a blank slate for innovative artists. Early exhibits included "Bathroom Window Optics" that created ghostly geometric light forms from Christmas tree lights filtered through textured glass. The "Cybernetic Serendipity" exhibition featured pieces that turned sound into ever-changing television images-entrancing even deaf children who could see their vocal efforts creating patterns.
Art had always been central to Frank's life. He carried his flute everywhere, encouraged staff to display their talents, and his home featured works including Picassos. His aesthetic sensibilities extended to everyday objects-he railed against vacuum cleaners that were "hard to steer," plastic-packaged batteries that made "that awful crinkly noise," and museums like the Guggenheim where visitors could walk only one way.
Frank believed aesthetics should be central to decision-making, not merely decorative. He lamented that Congress didn't visit art galleries for guidance on difficult matters, and that when money was tight, aesthetics was first sacrificed. He argued that places respecting arts made better decisions and "better things happen." If art were valued more, he wrote to David Rockefeller, "many of the things that now shock or degrade people's sensitivities would not be tolerated."
While science was territory people could acceptably avoid, art was "culture"-a realm where everyone was expected to feel at home. Yet museums often seemed unwelcoming: either musty mausoleums demanding reverence or antiseptic spaces requiring hushed appreciation. Most people viewed museums like churches or schools-places to be revered rather than enjoyed.
Frank's approach was radically different. With him, museums became adventure parks where one should race around, talk loudly, laugh, and touch things when guards weren't looking. At the Whitney Museum, he once posed as a Duane Hanson sculpture to see if visitors would poke him to determine if he was real.
Artists found the Exploratorium liberating. One remarked how his approach changed drastically after encountering the place-suddenly his work became about noticing things, experimenting like a scientist, and observing how people interact in public spaces.
Capítulo 9
The Sentimental Fruits of Science
During Frank's years on the ranch and at the University of Colorado, he spent considerable time trying to understand how science had somehow gone astray-either abdicating its proper role in society or being shoved out. His greatest concern wasn't weighing obvious positive contributions of science (like antibiotics) against sinister ones (like the atom bomb), but rather how scientific understanding could change the way people felt about themselves, nature, and each other.
Frank believed science's "sentimental fruits"-ways of thinking that could be applied to almost every realm of existence-were its most important contributions. He saw scientific principles reflected in social values: racial equality mirroring symmetry principles behind Einstein's relativity; tools for reconciling conflicts emerging from quantum mechanics; democracy and progress depending on accepting that everything constantly changes.
These ideas weren't unique to Frank-they connected him to intellectual predecessors like Bohr, Einstein, Schrodinger, and Max Born. Robert Oppenheimer expressed similar views, noting that "in the days of the founding of this republic, politics and science were of a piece" and that scientific discoveries "have changed the way men think of things outside its walls."
Perhaps the most obvious "sentimental fruit" of science is its effect on fear. Frank had experienced this firsthand as a child with a bronze figurine of a dog to which he attached rituals that had to be followed precisely or bad things would happen. The day he realized the dog was powerless and the rituals meaningless, he experienced enormous relief. Science had freed him from superstition, a lesson he never forgot.
Another "sentimental fruit" that mitigates fear is science's revelation of cosmic unity-the knowledge that nature isn't as complex as once thought. Newton's discovery that apples fall for the same reason planets orbit the sun connected heaven and earth. Darwin's theory showed we're all part of one vast family tree, related not just to each other but to all living things, erasing biological bases for class and racial distinctions.
Perhaps most surprising among the "sentimental fruits" was symmetry as the guiding force behind natural laws-the idea that fundamental truths are those that don't change, no matter what. In physics, symmetry describes a change that doesn't change anything, like rotating a snowflake 60 degrees.
These symmetries extend to human fairness. If you divide a resource into equal parts, it shouldn't matter who gets which piece-the outcome is symmetrical. The same applies to the Golden Rule. Frank believed understanding such symmetries could guide society creation, revealing that race, nationality, appearance, and economic status make no fundamental difference.
Capítulo 10
A Legacy That Ripples Outward
By 1981, the Exploratorium had begun to gain recognition. Frank's personal life had changed dramatically when his wife Jackie died of cancer in March 1980. He was devastated by her loss, and for months kept her belongings around the house, often speaking about how much he missed her.
Then unexpectedly, after returning from a trip to Colorado, Frank announced he had remarried. His new bride was Milly Danielson, an old friend from Boulder who Frank told his son Mike felt like a "continuum" with Jackie. Warm and tough, Milly was a social activist who welcomed Frank's eccentric circle and brought new elements into his life, including a grand piano.
Frank wielded absolute power at the Exploratorium while maintaining a paradoxical anarchy. Staff described following him like "grabbing onto a rope and being dragged along in the dust." Unpredictable and childlike, he could be dismissive or mean, but also joyous and uncommonly kind. Despite his eccentricities-disappearing without notice, meddling in every detail from lost-and-found boxes to exhibit labels-Frank had a genius for making people feel they had influence.
The Exploratorium thrived on chaos and open-endedness. Frank delighted when visitors used exhibits in unintended ways-girls letting their hair stream up in the Bernoulli Blower's air current, kids cooling their bellies with it. Whether discoveries were "right" didn't matter as much as their authenticity.
Frank's administrative decisions were based on idealistic rather than practical considerations. When board members later accused him of being a poor administrator, he agonized over what "administer" meant, ultimately deciding it meant literally to minister to people-a one-on-one affair. His management style involved wandering through the shop like "a happy cloud," asking people "Whatcha doin'?" and having personal conversations.
Frank's unconventional approach to running the Exploratorium created tensions with the board of directors, who increasingly wanted more business-like management. Despite the museum's success and stellar reputation, the board grew concerned about financial stability. Frank resisted appointing a successor, believing the staff could carry on without him. When forced to implement an admission charge due to financial pressures, he insisted that anyone under eighteen could enter free and that a ticket bought a six-month pass with unlimited visits.
The crisis came to a head in 1983 when the board told Frank he should remain the "conceptual and inspirational" leader while day-to-day management should go to someone else-a suggestion he found unthinkable and deeply hurtful. That same year, his beloved dog Orestes died in a car fire, and Frank was diagnosed with terminal lung cancer following an earlier battle with lymphoma.
Frank spent his final weeks at home, with family around him as visitors streamed in to say goodbye. He approached death like a scientist-fully conscious of the process and focused on "noticing"-discussing the physical sensations he was experiencing as "just another phenomenon." On February 3, 1985, Frank died at home.
Frank's influence continues to spread like a wave rather than a momentary splash. The Exploratorium has influenced 90 percent of U.S. science museums and 70 percent of museums worldwide, with spinoffs in cities from Beijing to Rio de Janeiro, from Moscow to Saudi Arabia. Nearly twenty-five years after Frank's death, roughly thirty staff members from his era were still working at the Exploratorium-a testament to the family character the place retains.
In his 1960 speech to the graduating class of Pagosa Springs High School, Frank Oppenheimer shared his philosophy for living a meaningful existence. He expressed gratitude for his rich life, explaining that fulfillment comes from "continually taking things seriously-but not too personally." He concluded by encouraging graduates to intervene for justice when opportunities arise, and to become deeply involved in things they find important: "I recommend that you be willing to become deeply involved in lots and lots of things and that you let yourself, perhaps even force yourself, to do the things that you think are important and that you can take seriously." This approach, he promised, would lead to gratitude for having lived and eagerness for more of the same, even in the face of adversity.
