Category Archive: Physics

The Scientist qua Scientist Has a Duty to Advocate and Act

Don Howard

The new AAAS web site on climate change, “What We Know,” asserts: “As scientists, it is not our role to tell people what they should do or must believe about the rising threat of climate change. But we consider it to be our responsibility as professionals to ensure, to the best of our ability, that people understand what we know.” Am I the only one dismayed by this strong disavowal of any responsibility on the part of climate scientists beyond informing the public? Of course I understand the complicated politics of climate change and the complicated political environment in which an organization like AAAS operates. Still, I think that this is an evasion of responsibility.

Contrast the AAAS stance with the so-called “Franck Report,” a remarkable document drawn up by refugee German physicist James Franck and colleagues at the University of Chicago’s “Metallurgical Laboratory” (part of the Manhattan Project) in the spring of 1945 in a vain effort to dissuade the US government from using the atomic bomb in a surprise attack on a civilian target. They started from the premise that the scientist qua scientist has a responsibility to advise and advocate, not just inform, arguing that their technical expertise entailed an obligation to act:

“The scientists on this project do not presume to speak authoritatively on problems of national and international policy. However, we found ourselves, by the force of events, during the last five years, in the position of a small group of citizens cognizant of a grave danger for the safety of this country as well as for the future of all the other nations, of which the rest of mankind is unaware. We therefore feel it is our duty to urge that the political problems, arising from the mastering of nuclear power, be recognized in all their gravity, and that appropriate steps be taken for their study and the preparation of necessary decisions.”

James Franck. Director of the Manhattan Project's Metallurgical Laboratory at the University of Chicago and primary author of the "Frank Report."

James Franck. Director of the Manhattan Project’s Metallurgical Laboratory at the University of Chicago and primary author of the “Franck Report.”

I have long thought that the Franck Report is a model for how the scientist’s citizen responsibility should be understood. At the time, the view among the signatories to the Franck Report stood in stark contrast to J. Robert Oppenheimer’s definition of the scientist’s responsibility being only to provide technical answers to technical questions. Oppenheimer wrote: “We didn’t think that being scientists especially qualified us as to how to answer this question of how the bombs should be used” (Jungk 1958, 186).


J. Robert Oppenheimer Director of the Manhattan Project

J. Robert Oppenheimer
Director of the Manhattan Project

The key argument advanced by Franck and colleagues was, again, that it was precisely their distinctive technical expertise that entailed a moral “duty . . . to urge that the political problems . . . be recognized in all their gravity.” Of course they also urged their colleagues to inform the public so as to enable broader citizen participation in the debate about atomic weapons, a sentiment that eventuated in the creation of the Federation of American Scientists and the Bulletin of the Atomic Scientists. The key point, however, was the link between distinctive expertise and the obligation to act. Obvious institutional and professional pressures rightly enforce a boundary between science and advocacy in the scientist’s day-to-day work. Even the cause of political advocacy requires a solid empirical and logical foundation for that action. But that there might be extraordinary circumstances in which the boundary between science and advocacy must be crossed seems equally obvious. And one is hard pressed to find principled reasons for objecting to that conclusion. Surely there is no easy argument leading from scientific objectivity to a disavowal of any such obligations.

Much of the Franck report was written by Eugene Rabinowitch, who went on to become a major figure in the Pugwash movement, the leader of which, Joseph Rotblat, was awarded the 1995 Nobel Peace Prize for his exemplary efforts in promoting international communication and understanding among nuclear scientists from around the world during the worst of the Cold War. The seemingly omnipresent Leo Szilard also played a significant role in drafting the report, and since 1974 the American Physical Society has given an annual Leo Szilard Lectureship Award to honor physicists who “promote the use of physics to benefit society.” Is it ironic that the 2007 winner was NASA atmospheric physicist James E. Hansen who has become controversial in the climate science community precisely because he decided to urge action on climate change?

That distinctive expertise entails an obligation to act is, in other settings, a principle to which we all assent. An EMT, even when off duty, is expected to help a heart attack victim precisely because he or she has knowledge, skills, and experience not common among the general public. Why should we not think about scientists and engineers as intellectual first responders?

Physicists, at least, seem to have assimilated within their professional culture a clear understanding that specialist expertise sometimes entails an obligation to take political action. That fact will, no doubt, surprise many who stereotype physics as the paradigm of a morally and politically disengaged discipline. There are many examples from other disciplines of scientists who have gone so far as to risk their careers to speak out in service to a higher good, including climate scientists like Michael Mann, who recently defended the scientist’s obligation to speak up in a blunt op-ed in the New York Times, “If You See Something, Say Something”). The question remains, why, nonetheless, the technical community has, for the most part, followed the lead of Oppenheimer, not Franck, when, in fact, our very identity as scientists does, sometimes, entail a moral obligation “to tell people what they should do” about the most compelling problems confronting our nation and our world.


Jungk, Robert (1958). Brighter than a Thousand Suns: A Personal History of the Atomic Scientists. New York: Harcourt, Brace and Company.

Nuclear Options: What Is Not in the Interim Agreement with Iran

Don Howard

No one wants war with Iran over its nuclear ambitions. But the euphoria over the EU3+3 interim agreement with Iran, as well as many of the political attacks on the agreement, obscure core technical issues that should be fundamental to any assessment of what has really been achieved. There is no denying that much has been gained by way of Iran’s agreeing temporarily to cease uranium enrichment beyond the 5% level necessary for energy production and its agreeing to on-site inspections at its Fordow and Natanz facilities. But important questions remain about what is not included in the interim agreement. Here are four issues that should be more prominent in the debate:

1. The Interim Agreement Mandates No Reduction in Iran’s Capability for Uranium Enrichment. Iran agrees to cease uranium enrichment beyond the 5% level necessary for energy production and not to expand or enhance its uranium enrichment capabilities, for the duration of the interim agreement. Moreover, Iran agrees to dilute half of its 20%-enriched uranium hexaflouride (UF6) to a 5% level and to convert the remaining half to uranium oxide (UO2) for use in making fuel for its Terhran research reactor. But Iran has not agreed to any permanent reduction of its capability for uranium enrichment, a capability that significantly exceeds what is necessary for energy production. It is hoped that a yet-to-be-negotiated, long-term agreement will include a reduction in that capability. But the interim agreement requires no such reduction. At any moment, Iran could resume enrichment to bomb-grade levels. Moreover, the UF6 that is to be converted to UO2 can be reconverted to UF6 and then further enriched.

Arak Heavy Water Reactor

Arak Heavy Water Reactor

2. The Interim Agreement Requires No Inspections at the Arak (IR-40) Heavy Water Reactor. As explained in a helpful recent article by Jeremy Bernstein, the Arak reactor is central to any evaluation of Iran’s nuclear ambitions. It is not designed as a reactor for power generation. Though Iran says that the reactor will be used to produce medical isotopes, its most plausible purpose is to be a breeder reactor for the production of plutonium, which is the other standard fuel for atomic weapons that rely upon the process of nuclear fission (as with the North Korean bomb). It was Iran’s refusal to allow on-site inspections at the Arak reactor that stalled the talks a couple of weeks ago when France demanded more access to Arak. The new interim agreement does require Iran to provide to the International Atomic Energy Agency (IAEA) an updated “Design Information Questionnaire” regarding the Arak reactor, it stipulates that there will be no “further advances of [Iran’s] activities at Arak, it obligates Iran to take “steps to agree with the IAEA on conclusion of the Safeguards Approach for the reactor at Arak” (whatever that means), and Iran agrees to do no reprocessing of spent fuel (the main purpose of which would be to extract plutonium) and not to construct reprocessing facilities. But the interim agreement does not obligate Iran to allow on-site inspections at Arak. Inspections are stipulated for the Fordow and Natanz uranium enrichment facilities, but not at Arak. Iran’s intransigence on this point should give us pause as we try to determine the real purpose of that reactor. If plutonium production is the goal, then our obsession with Iran’s uranium enrichment capability could be distracting us from a more serious threat. A quick route to an Iranian atomic bomb could well be via plutonium produced at Arak. And, at present, Iran has agreed to no degradation of this potential plutonium production capability.

3. The Interim Agreement Does Not Address the Question of Weapons Delivery Systems. Iran is a technically sophisticated nation that has made impressive advances in missile technology in recent years. Much of this missile technology was borrowed from earlier Russian and Korean models. But the new, solid-fuel, Sejil-2 rocket, which was first tested five years ago, is an original Iranian design. It has an impressive, 2,000-km range with a 750 kg payload capacity and anti-radar coatings. The Sejil-2 could put a nuclear warhead on a target as far away as Cairo, Athens, or Kiev. Moreover, Iran has been making gains in its guidance technology.

That we should be paying attention to Iranian weapons delivery capabilities was made clear when, two days after the announcement of the interim agreement, Brigadier General Hossein Salami, the Lieutenant Commander of the Iranian Revolutionary Guard Corps IRGC), announced that Iran’s indigenous ballistic missile capability had recently achieved a “near zero” margin of error in targeting accuracy.

That it was General Salami who made the announcement about advances in Iranian ballistic missile technology reminds us of a political, not technical, issue that has also received insufficient attention in the public debate about the interim agreement. The question is, “Who is really in control?” The interim agreement was negotiated by Iranian Foreign Minister Mohammed Javad Zarif on behalf of the government of President Hassan Rouhani. But the Revolutionary Guard functions as almost a shadow government, with considerable independent authority. And much of the most impressive Iranian ballistic missile research and development has been conducted in facilities under IRGC control, such as the IRGC missile base at Bid Kaneh, where a mysterious explosion during a missile test in November 2011 killed General Hassan Tehrani Moqaddam, who was the head of the IRGC’s “Arms and Military Equipment Self-Sufficiency Program.”

4. The Interim Agreement Does Not Address Aspects of Nuclear Weapons Technology Aside from the Production of Fissile Materials. Nothing in the interim agreement restricts Iran’s ability to continue developing other technologies essential to nuclear weapons production, such as timing circuitry, detonators, and refined conventional explosives techniques involved in the assembly of a critical mass of fissile material. It is perhaps not well and widely enough understood that some of the bigger technical challenges for a nation seeking nuclear weapons lie not in the production of fissile material but in areas such as these. Consider the basic design of a plutonium bomb of the kind dropped on Nagasaki. A critical mass of plutonium is achieved by compressing the plutonium with a spherical blast wave from spherical shell of conventional explosives. The precise shaping of those conventional explosive charges and their precise, simultaneous detonation are among the most difficult technical challenges in bomb design and manufacture. By contrast, while enriching uranium and breeding plutonium require a major technical infrastructure, the physical, chemical, and engineering processes involved are widely understood and, in principle, not all that difficult to achieve. But the interim agreement places no obstacles in the way of research and development on these other aspects of nuclear weapons design. Iran is free to pursue such research as vigorously as it will and to produce a fully functional nuclear weapon awaiting only the insertion of the fissile material.

An assessment of what has been achieved with the interim agreement depends crucially upon a prior assessment of Iran’s goals with respect to nuclear weapons capability. If Iran’s aim had been to produce nuclear weapons as soon as possible, then the interim agreement at least slows down progress toward that goal. But another view is that Iran’s aim all along has been to develop the basic technical infrastructure for the rapid production of bomb-grade fissile material for use if and when it chooses. If that is Iran’s aim, then the interim agreement achieves much less by way of delaying progress to the goal.

We have to wait and see how the interim agreement works. But the celebration of seeming progress on the diplomatic front must be tempered by a clear understanding of the technical issues that are not addressed in the interim agreement, issues that must be the focus of any, longer term, follow-on agreement. Should there be no progress on enrichment capabilities, the Arak reactor, delivery systems, and the fundamentals of bomb design, then options other than diplomacy might have to be explored, starting with the re-imposition of sanctions.

Physics as Theodicy

Don Howard

A few years ago I had the good fortune to participate in a great conference at the Vatican Observatory on “Scientific Perspectives on the Problem of Natural Evil.” The conference was organized by the Center for Theology and the Natural Sciences, at Berkeley, and co-convened by CTNS and the Vatican Observatory. The Observatory shares Castel Gandolfo with the Papal summer residence, and Pope Benedict was in residence during the entirety of the conference. Many fond memories, among them a state visit by Queen Noor of Jordan, and our being serenaded by Benedict one afternoon as he practiced a Beethoven sonata on the piano. But the really cool thing was being saluted by members of the Swiss Guard every morning as we entered and every evening as we left, snapping to attention with the greeting, “Buongiorno” or “Buonasera.”

Nancey Murphy, Robert John Russell, and William Stoeger, S.J., eds. Physics and Cosmology: Scientific Perspectives on Natural Evil. Vatican City: Vatican Observatory, 2007.

There were many fine presentations by a first-rate group of scholars. I measure the quality of a conference by how much I learn that is new and interesting to me. By those metrics, this meeting is among the very best I’ve ever attended. Take a look at the contents of the published volume, which came to fruition largely through the efforts of Nancey Murphy and her colleagues at Fuller Theological Seminary in Pasadena, and was co-published by CTNS and the Vatican Observatory:

Physics and Cosmology: Scientific Perspectives on the Problem of Natural Evil

My own presentation was entitled “Physics as Theodicy.” A “theodicy” is a solution to the problem of natural evil. Traditionally we distinguish “natural evil” from “moral evil.” Natural evil is suffering that is a consequence of the operation of natural law. Death and destruction wrought by earthquakes, hurricanes, and disease are classic examples. Moral evil concerns suffering in consequence of the moral failings of human beings. Murder, slavery, and too many other sins afford examples. The classic problem of natural evil, famously discussed by Leibniz in his Théodicée (1710) and Voltaire in Candide (1759), is how there can be natural evil in a world governed by an omnisicient, omnipotent, and benevolent God. Leibniz argued that ours is the best of all possible worlds, a view echoed by Alexander Pope in his “Essay on Man” (1734) and viciously mocked by Voltaire.

The traditional problem of evil interests me less than the question of where and how we draw the line between natural and moral evil. The main point of my talk was a simple one: With the progress of science, physics leading the way, we learn more about the laws of nature and so acquire an ever greater capacity to prevent or ameliorate the suffering caused by disease or natural catastrophes. We still cannot prevent an earthquake or a tsunami, but we can predict them, and we can build office towers and bridges that can survive an earthquake, sea walls that can control storm surges, and warning systems that can give people time to take refuge. But do we choose to exercise this power? If we could have prevented a catastrophe or lessened the suffering, but chose not to do so, then the evil is moral, not natural. Thus, with the progress of science, the boundary between natural and moral evil shifts. As science teaches us more about our world, we must accept the moral responsibility for making the world a better place. Even without global climate change, Hurricane Katrina would have been a terrible storm. But at the very least, we could have built stronger dikes. We could not have prevented the earthquake that caused the horrific Indian Ocean tsunami of 2004, but we could have put in place a tsunami warning system that would have saved many tens of thousands of lives. Those deaths are our fault, not nature’s or God’s.

Want to know more? You can download the full paper here:

“Physics as Theodicy”
(Made available here with the permission of the Vatican Observatory.)

And you can buy the book through the University of Notre Dame Press:

How to Talk about Science to the Public – 1. Don’t Insult the Intelligence of Your Audience

Don Howard

About ten years ago I wrote the Einstein article for the new edition of a major encyclopedia. It shall remain unnamed, but you would most definitely recognize it. I enjoyed the challenge and am proud of the product, both because such writing is important and because it is hard work. One must be engaging, intelligible, and concise. Academics must resist the urge to splurge on words.

Writing this article was, however, harder than it should have been, because my editor kept repeating the old journalist’s mantra about writing to the level of the typical fourteen-year-old. We fought. I resisted. He won. He demanded plainer language. He insisted on tediously pedantic explanations of what I thought the reader would see as simple, even if slightly technical concepts. He struck whole paragraphs that I thought were wonderful and he thought were too arcane. Time and again I said that the real fourteen-year-olds I knew could easily understand points that he thought beyond the reach of his imaginary, teen reader. I don’t think that I made a friend. I taunted him by noting that the reader confused about concept X could simply look up the article on X elsewhere in the same encyclopedia. Impolitic, yes, but I couldn’t stop myself. Naughty Don.

A few years later I was asked to do a series of lectures on Einstein for the company then called The Teaching Company and now re-branded as The Great Courses. This was a totally different and far more enjoyable experience, largely because the smart folks in charge at The Great Courses start with a very different assumption about the audience. They asked me to imagine an audience of college-educated professionals, people who loved their student experiences and were hungry for more. Of course, one still had to adjust one’s writing to the level and background of the audience, as one must do with any class one teaches. That is a trivial truth. But what I knew about those kinds of students in my classes was that they wanted to be pushed and challenged. They wanted to be taught new things. They didn’t run in fear of difficult concepts and ideas. Like athletes striving for a personal best, they enjoyed the hard work. The muscles ache, the brain needs a rest, but the achievement makes it worthwhile. Most important is that such students appreciate one’s flattering them with the assumption that they have brains, that they are smart, well-educated, and able to rise to the moment.

I am really proud of the lectures: Albert Einstein: Physicist, Philosopher, Humanitarian. The uniformly positive feedback confirms the point that the intelligent student, reader, and listener can and wants to understand more than journalistic mythology asserts.

Don Howard. Albert Einstein: Physicist, Philosopher, Humanitarian. The Great Courses.

My old encyclopedia editor friend will object, I’m sure: “What about all of the others, the ones who didn’t have a college education or weren’t even ‘B+’ students?” Well, yes indeed, what of them? They are a numerous lot. And if one has the crime “beat” at the local newspaper or writes the “Friends and Neighbors” column, then, yes, ok, I suppose that one must write down to the level of a poorly-educated, fourteen-year-old.

But is that the audience for those of us who write about science for a general public? I hope not. Is it elitist of me to say that I don’t want “Joe the Plumber” making science policy for the 21st century?

I like to think of the main target audience for good science writing as the educated, scientific laity or those (such as smart high school students) who are soon to become part of it. These are the neighbors and fellow citizens who must be involved in the national and global conversation about science and technology for the future. These are the people whose voices should count in debates about climate change, biotechnology, space exploration, and cyberconflict. These are the people for whom we must learn to write and speak.

They deserve our respect.

(Subsequent posts in this series will address more specific challenges in writing about science and technology for the general public.)

Physics and Humility

Don Howard

(Orignally written a few years ago as sort of an op-ed after an interesting meeting on fundamental physics in the gorgeous resort town of Lake Bled in Slovenia, “Time and Matter 2007.”)

As the sun sets over the Julian Alps, as evening embraces the Assumption of Mary Pilgrimage Church in the middle of Lake Bled in Slovenia and church bells herald day’s end, we come to the conclusion of Time & Matter 2007, an unusually diverse gathering of physicists and philosophers, assembled here to bring their different perspectives to bear on the deep, unsolved problems of contemporary physics.

Assumption of Mary Pilgrimage Church Lake Bled Slovenia (Slovenian: Cerkev Marijinega vnebovzetja)

In the one hundred years since the quantum and relativity revolutions, advances in fundamental physics have completely transformed our understanding of nature. Powerful particle accelerators allow us to probe the structure of the tiniest subatomic particles, while orbiting observatories let us look out to the edge of the universe and back in time to its beginnings. No century produced an expansion of physical knowledge such as we saw in the twentieth century.

But where do we stand now? Modern physics is built on two foundations. Einstein’s theory of general relativity explains gravitation and the large-scale structure of the universe. Quantum mechanics–the work of Einstein, Max Planck, Niels Bohr, Werner Heisenberg, Erwin Schrödinger, and others–is the framework for explaining the other three fundamental forces–electromagnetism, and the strong and weak nuclear forces. With quantum field theory and the so-called “standard model” of particle physics–the quark model–quantum mechanics explains the microstructure of the universe. Part of what’s remarkable about twentieth-century physics is that each of these theories has been confirmed with extraordinary precision. One could be forgiven for thinking that we are on the verge of achieving a complete and final understanding of nature.

And yet the presentations and conversations here at Lake Bled have been dominated by talk of theoretical analyses and experimental tests that could very well refute every one of these theories. Tests of what are known as Einstein-Podolsky-Rosen correlations in neutral kaon decay could refute quantum mechanics. The still unresolved black-hole information loss paradox could point to a fundamental contradiction between quantum mechanics and general relativity. When CERN’s large hadron collider begins operation in 2008 the standard model might be refuted if the Higgs boson is not detected. More than one talk at Time & Matter 2007 used the acronyms, “BSM” and “NP” for “beyond the standard model” and “new physics.”

But more than anything else, the question looming over the meeting–in conversation at the opening reception and in talks on the closing day–are the problems of dark matter and dark energy. Within just the past ten years, observation has shown that the universe is populated with a strange form of matter, “dark matter,” that interacts gravitationally with ordinary, “baryonic” matter but is otherwise invisible, so far, to our current physics. Other observations have shown that the expansion of the universe is accelerating in a way seemingly explainable only if it is filled with a still stranger stuff, “dark energy,” that is completely invisible to current physics. Moreover, we now think that 96% of the universe consists of this strange new stuff. According to our best estimates, 22% of the universe is dark matter, and 74% is dark energy. That means that only 4% of the universe is made up of the kind of stuff–baryonic matter–that is explained by all of the revolutionary, new, physical knowledge that we accumulated in the twentieth century. That’s right. After all that hard work, our current best physics explains, at most, 4% of what’s in the universe.

There is irony in the fact that it was the very physics whose dramatic shortcomings are now revealed that made possible the discovery of those limitations. And physicists are to be admired for the fact that, proud as they are of what they’ve done, they turn right around and subject it all to tough, critical examination. No dogma here, just the patient, steady, self-critical effort to know more. But perhaps most important is the lesson of that 4% figure. The discovery of dark matter and dark energy provide the clearest proof known to me of the basic insight of Socrates, that wisdom lies in knowing what it is that we don’t know, that intellectual humility is the mark of true wisdom.

These are very exciting times in physics.

Bled, Slovenia
August 31, 2007