BLP Conversations: David C. Cassidy & Dava Sobel

Welcome to the BLP Conversations series, featuring dialogues between people whose lifework, like BLP’s mission, explores the creative territory at the intersection of the arts and sciences, and has become a testament to how science and the humanities can join forces to educate and inspire. This online series is inspired by E.O. Wilson and Robert Hass, whose talk about the connections between science and the arts was published in our book The Poetic Species: A Conversation with Edward O. Wilson and Robert Hass.


In this conversation, David C. Cassidy, author of Beyond Uncertainty: Heisenberg, Quantum Physics, and the Bomb, and best–selling science writer Dava Sobel discuss the “quantum leap of creative imagination” it took to make the transition into writing historical science drama. Staged readings of their first plays—Cassidy’s Farm Hall, about captured German nuclear scientists at the end of World War II, and Sobel’s And the Sun Stood Still, about Nicolaus Copernicus—were presented before meetings of the American Physical Society.

Dava Sobel: I read the Copernicus story for the first time in early 1973, in the February issue of Sky & Telescope. His picture was on the cover and Edward Rosen’s article inside explained the circumstances of the long publication delay for De Revolutionibus Orbium Coelestium—until Rheticus arrived to overcome Copernicus’s hesitation. I was so struck by the effect of their conversations, and of course so curious to know what they’d said to each other.

Reconstructing the likely exchange in drama form seemed a good way to get at the essence of the arguments. I thought about the play for quite a while, and had been a theater major (for a few terms) in college. In 1973, I lacked the courage to attempt writing a play. But I never forgot the idea, and finally—about ten years ago—I worked up the will to try it.

David C. Cassidy: Farm Hall found me, rather than the reverse. I was in Washington, DC in 1992, shortly after the National Archives released the Farm Hall transcripts to the public. These are transcriptions of conversations among leading German nuclear scientists during a six-month period at the end of World War II when Allied authorities held the scientists captive at an English country manor, Farm Hall, near Cambridge. British intelligence agents secretly recorded the conversations and translated selected portions for their superiors, including the commanding general of the Manhattan Project.

I immediately recognized the 150 pages of conversations to be a play waiting to happen. During my overly ambitious early college years I had started out majoring in English as well as in math and physics. I also dabbled in creative writing. I soon dropped the first two subjects, but never lost an interest in physics or in writing. By 1992, I was a historian of physics and had recently published a biography of Heisenberg, one of the key figures at Farm Hall. But at that time the historical implications of these transcripts exerted a stronger pull on me than did their dramatic possibilities. Soon I was drawn into the historical controversy surrounding Michael Frayn’s Tony-award-winning play Copenhagen, which came to Broadway in 2000.

A decade later found me completing a series of three books related to twentieth-century physics history. I was looking for a new challenge, for something other than yet another book or paper in a field that, for me, was growing less interesting as it grew more esoteric. I had expected that by then someone would have already turned the Farm Hall transcripts into a play. Just at that moment, Brian Schwartz, director of the program Science and the Arts at the CUNY Graduate Center, suggested that I should take on the task. I knew the history, he argued, and, I surmised, I should be able to learn dramatic writing without much difficulty. (How wrong I was about that!) I also thought that since history and drama are usually about people in extraordinary situations, drama could be another medium through which to explore and express the themes that I had long sought to bring to the public. I took the plunge.

DS: As soon as you acknowledged the unexpected difficulty you encountered in the dramatic form, you opened another fruitful area for discussion. The process brought me to my knees. I had always been good, as a journalist, at selecting and shaping quotes from interviews to enliven news stories. I’d seen and read probably hundreds of plays—but without ever analyzing what made play dialogue so different from interesting conversation.

After I got to my third or fourth draft, I showed my script to Gerald Freedman, who was then dean of Drama at the University of North Carolina School of the Arts, where my son was a student. I’ll never forget Gerald’s comment, here reconstructed from memory: “You’ve written a book, not a play. It looks like a play, the way it’s arranged on the page, but it’s a book. The characters speak in whole sentences—whole paragraphs, in fact. If one asks a question, the other answers it. The dialogue is altogether too linear, too logical. People don’t talk that way. Even five hundred years ago, they didn’t talk that way.”

At the same time, he gave me the full force of his encouragement. A terrific criticism of a later draft concerned dialogue that sounded too “on the nose.” I needed to do less spelling out, more letting the audience figure out.

Gerald was also the one who pushed me to make a decision about Copernicus and Anna. When I was writing only a play (as opposed to a play inside a book), I kept waffling on the nature of their relationship. Were they really an item? Or just the victims of idle gossip? “You’ve got to bite the bullet,” Gerald said, “and make him fall in love with her. Otherwise there’s nothing at stake.”

“Stakes” turned out to be the crucial new concept. It seems so obvious now, but at the time…

You and I have approached the playwriting challenge from opposite situations. You started with actual transcripts that you molded into dramatic form. I had the freedom to create the content of lost conversations. I think we could talk about those processes. I’m curious, for example, which task strikes you as the more difficult?

While I was working on my play, I “gave thanks” every morning that Michael Frayn and Tom Stoppard hadn’t gotten to Copernicus first. I’d be very interested to hear what it was like writing Farm Hall after Copenhagen.

DC: I think what stands out for both of us are the hurdles we had to overcome in making the leap into playwriting. I did have the advantage of beginning with the transcripts, since they already look like a play and contain much useful dialogue. But, as you indicated, that doesn’t mean they are a play. I learned this once before when I naively asked some students to act out a selection from Galileo’s Dialogue Concerning the Two Chief World Systems. Even their most heroic efforts were to no avail.

While the transcripts did provide starting points for situations, some pithy dialogue, and a general plot, they also imposed constraints that required a difficult balancing act between fact and fiction. Looking back, I don’t think I could have picked a more difficult subject for my first play. For me, the most difficult aspect was indeed the role of imagination: how far could I allow my imagination to wander from the actual events in order to create a viable play? I had spent years as a historian trying to get the facts straight and the quotations verbatim. Drama seemed to demand just the reverse.

Fortunately, Teri Black and the New York theater company Break A Leg Productions offered me wonderful help and much-needed encouragement from the very start. One of their main suggestions was that I find a dramaturge to help me develop the script. I am very grateful that the then-head of the Drama department at Hofstra University where I teach, Jean Dobie Giebel, a noted director and dramaturge, was kindly willing to take on the challenge. I also did a lot of reading about drama and drama history, and I read many important plays and viewed relevant films. I also benefitted greatly from a drama course with the award-winning playwright Laura Maria Censabella.

As a former physicist, I was surprised to learn from my reading that Western drama is still founded upon the insights presented by Aristotle long ago in his Poetics. Aristotle confirmed for me what I was already beginning to suspect: historical drama must remain fair to history, even as it diverges from it. Drama cannot contradict what happened, but it can extrapolate from the actual events and characters what must or could or should have happened. This made a lot of sense to me. One dramatist later remarked, “That’s why they call it theater, not history.”

Although you were thankful that Frayn or Stoppard had not gotten to Copernicus before you did, I was quite grateful that Frayn’s Copenhagen had already brought the issues of Heisenberg and the atomic bomb before the public. Far from being a hindrance, his play convinced me that audiences would be interested in a historical play with science in it—if it is done right. Moreover, his work enabled me to create my play as a kind of sequel to Copenhagen, for those familiar with it. Farm Hall takes place four years later, at the end of the war during the months before and after the dropping of the atomic bombs on Japan. So, in a way, it brings to a climax the issues surrounding German research and the scientists’ work for their government in that period. However, I was careful not to rely on Copenhagen, since it is now about fifteen years later. For those in the audience familiar with the play, I had the characters briefly recall with a bit of irony the events depicted in Frayn’s play. Judging from audience reactions so far, including physicists, the difficult historical aspects of Farm Hall seem to be working.

DS: Actors from the Boulder Ensemble Theatre Company turned out a performance that thrilled me. Most of these same actors had joined me last fall in a week-long workshop to improve the script. I had sought out a workshop situation because I knew that the play, as originally published in my book, A More Perfect Heaven, lacked dramatic energy. It worked well enough in the book—to help readers understand the seeming insanity of proposing a moving earth in the sixteenth century, as well as to lend dimension to the character of Copernicus, who left only a handful of letters on personal matters. The script also worked reasonably well as a staged reading, but I feared it would fall flat in a fully staged production, and I couldn’t identify what changes would give it the boost it needed. The published script called for six characters: Copernicus, of course, plus Rheticus (the young genius from Wittenberg who visits him and convinces him to publish), the Bishop (Copernicus’s superior), Giese (the Bishop of the neighboring diocese who is Copernicus’s best friend), Anna (the housekeeper), and Franz (a fictional character I inserted as the Bishop’s acolyte). At the first evening’s read-through in Boulder, director Stephen Weitz suggested to me that Franz didn’t belong in the play. I had invented him as a foil to move along parts of the action, but Stephen argued that Franz exerted no influence on Copernicus, and raised issues that diverted attention from the story’s essence: “If you get rid of him and rewrite around him, everything will come together. You’ll see.” I stayed up much too late several nights that week in the effort to “kill Franz,” but the result proved Stephen right. On my own, I’m sure I would never have identified Franz as the problem. Now I’m finally happy with the script.

DC: At one level, historical science writing and playwriting appear to have a lot in common. Both tell a story, both have a theme or point that they pursue, both attempt to engage the reader, both require some science exposition for non-scientists, and both (history at least sometimes) entail character development through actions and motives. But on a deeper level they differ widely in the nature of their aims and methods. History of science, as I pursue it, attempts to reveal what happened, why it happened, and what it means for us today. This requires some creativity, and one can write with considerable passion, but in the end it is a rational story intended to engage readers’ rational faculties.

I have learned that playwriting is, instead, primarily about emotion, even when it deals with science. The characters and the story are driven by motives and emotions. Scientists often do get emotional about their work and activities, but the standard trajectory of conflict, crisis, climax, conclusion—that forms the backbone of drama—is usually absent from history. I also became more aware that a play’s primary purpose is to entertain rather than to inform or teach, and, as such, it must evoke an emotional reaction from the audience, even if it is a negative reaction. The difficulty I have is that the necessary emotional material is not usually available in the historical record. This again requires a quantum leap of creative imagination that, in the end, must be fair to history and not contradict the science or the essential facts.

Another important difference I have noticed is that historical science writing is usually a solitary affair, involving a single researcher working and writing alone. Playwriting, in contrast, is from the start a thoroughly social process. Perhaps that is because the latter is so much more an appeal to the heart than to the head.

Balancing all of the many elements that must go into a successful play, while trying to stay true to the real characters and events, has been for me a great challenge, but also a great enjoyment.

DS: The only similarity I found between playwriting and my usual nonfiction is the effort to bring a scientist to the attention of non-scientists. That effort entailed a long period of research to familiarize myself with the scientist’s work and the world that surrounded it. Everything else felt different, especially making up dialogue for characters out of history. As a journalist, I was so averse to putting words in Copernicus’s mouth that I sacrificed the drama of his situation in several early drafts. It took a long time, many rewrites, and the urging of a director to convince me that it was okay—that indeed it was necessary—for Copernicus the character to be in a loving relationship with his housekeeper.

Another difference I discovered was the absence of science explication. I found I couldn’t make the characters explain things to one another without making the action come to a halt. It was more important to show Copernicus and Rheticus conversing as two mathematicians who spoke the same language, throwing around words like “epicycle” and “armillary sphere,” than it was to try explaining those concepts in dialogue.

My early scripts were too logical, too linear. The characters spoke in full sentences, even full paragraphs, listening to one another and responding to each other’s questions. Again, it took a long time before I could make one character interrupt or ignore any of the others.

The exercise of writing a book around the play proceeded in a much more straightforward fashion.

DC: A lot of my science historical work has been twofold: first, explorations of how seemingly ordinary people endowed with considerable talent in science were able to achieve their great scientific breakthroughs; second, most of the people I have dealt with lived during the twentieth century, a century of great scientific and human upheaval, and I wanted to explore how and why these otherwise ordinary people reacted as they did to the enormous moral, political, and personal challenges to science and humanity during that century. I also wanted to bring what I learned to general educated audiences as well as to working scholars and scientists. Through much research and writing, I was able to recreate a fairly accurate rational understanding of how they saw themselves and their world and their own actions, and how we in hindsight see them. Playwriting, in contrast, offers an entirely different, emotional perspective from which to explore these same issues and to reveal the human aspects behind them, while at the same time engaging a broad audience in an entirely different way.

DS: Plays reach a different non-science audience. I’ve been surprised to see how eager theatergoers are to view science on stage. Brecht’s Galileo has dominated the field for far too long. Many exciting science stories are now emerging in play form. Plays make great interdisciplinary vehicles for university theater departments, where I think they will succeed in spreading a greater interest in—and appreciation of—science and scientists.

If there’s a misfit, it concerns staging inventions. I made up a Copernicus “world machine” that allowed for planetarium lighting effects. I thought scene and lighting designers would have fun creating the machine, and audiences would enjoy the idea of “riding” in a concept. Unfortunately, many people who read my play assume that Copernicus really did build such a device. I am certain he did not.


Read more about the productions of Farm Hall and And the Sun Stood Still.


David C. Cassidy is the author of Beyond Uncertainty: Heisenberg, Quantum Physics, and the Bomb; A Short History of Physics in the American Century; J. Robert Oppenheimer and the American Century; and Einstein and Our World. He is the recipient of the Abraham Pais Prize for History of Physics from the American Physical Society, the Science Writing Award from the American Institute of Physics, the Pfizer Award from the History of Science Society, and an honorary doctorate from Purdue University. Dr. Cassidy is a Professor of Natural Sciences at Hofstra University and resides in Bay Shore, New York.


Dava Sobel, the Jacobson Visiting Nonfiction Writer at Smith College, is a former New York Times science reporter and a best–selling author of science for the general public. Her books include Longitude, Galileo’s Daughter, The Planets, and most recently A More Perfect Heaven.