Field of Science

On Patrick Blackett, the ideal experimental physicist, and what it takes to excel at interdisciplinary research

The grandly named Patrick Maynard Stuart Blackett was the Cambridge physicist on whose desk Robert Oppenheimer purportedly left a poisoned apple. The veracity of this yarn will likely never be determined, and it’s rather unfortunate that Blackett has been enshrined in the public's mind through this story, most notably by writer Malcolm Gladwell in his book “Outliers”.

This selective and sensationalized reporting is unfortunate because Blackett was the one of the most versatile and accomplished experimental physicists of the twentieth century. Not only was he an outstanding scientist who won the Nobel Prize for his research into cosmic rays and particle physics, but he was also a brave and decorated naval officer, a highly successful military scientist who pioneered operations research during World War 2, a vigorous campaigner for arms disarmament, and a writer of clear and engaging books advocating common sense thinking about weapons and warfare. This underappreciated scientist and government official deserves much more recognition than as the recipient of a possibly poisoned apple.

Athletic and handsome as a movie star with a finely sculpted face, Blackett saw raw action in the Battle of Jutland in World War 1. Between the war years he worked at the famed Cavendish Laboratory where he did much of his prizewinning work on cosmic rays. He and his colleague Giuseppe Occhialini discovered the positron (predicted by Paul Dirac) at the same time as American physicist Carl Anderson, but because the two wanted to confirm their discovery and were slow in publishing it, Anderson was the one who received the Nobel Prize for it (although Blackett was awarded his own prize for other work in 1948). The 'poisoned apple' incident emerges from this period. The story goes that Oppenheimer who was unsuccessfully trying his hand at experimental physics and suffering severe mental health problems as a result left the apple on Blackett's table out of sheer jealousy at Blackett's multifaceted personality and accomplishments. Even if the story is true it speaks to the kind of admiration Blackett could evoke.

During the war Blackett was one of the founders of the branch of mathematics and management science called operations research. He used this technique productively in trying to protect convoys against U-Boat attacks. After the war Blackett became an enthusiastic and sensible proponent of arms disarmament. As early as 1949 he wrote a book named “Fear, War and the Bomb” which argued against the efficacy of strategic bombing and the lure of nuclear weapons as instruments of warfare. In a time when the atomic bomb was seen as the linchpin of geopolitical strategy, this was a remarkably prescient and courageous position to adopt. Subsequent events have only vindicated Blackett's core thesis.

Blackett ended his career as a decorated scientist and public servant, having gathered many honors for his efforts and advice. Fortunately there are at least three books that vividly describe his life and times; volumes by Mary Jo Nye (2004), Peter Hore (2002) and most recently Stephen Budiansky (2013).

Blackett’s own writings on science and politics are worth reading, but here I want to highlight his views on what it takes to be an accomplished experimental physicist. It strikes me that Blackett’s take applies not just to experimental physicists but to any scientist who wants to straddle the boundary between two disciplines or modes of thinking. Here’s what he has to say (italics mine):
The experimental physicist is a jack-of-all-trades. A versatile, amateur craftsman he must blow glass and turn metal, carpenter, photograph, wire electric circuits and be a master of gadgets of all kinds. He may find invaluable his training as an engineer and can profit always by utilizing his gifts as a mathematician. In such activities will he be engaged for three quarters of his working day. During the rest he must be a physicist, that is he must cultivate an intimacy with the physical world, but in none of these activities taken alone need he be preeminent; certainly not as a craftsman, and not even in his knowledge of his own special field of physics need he, or indeed perhaps can he, surpass the knowledge of some theoretician… 
The experimental physicist must be enough of a theorist to know what experiments are worth doing, and enough of a craftsman to be able to do them. He is only preeminent in being able to do both. 
Blackett’s words are worth remembering for many reasons. First of all, he emphasizes the wide variety of tools that an experimental physicist needs to be proficient at. In fact Blackett says that good experimental physicists may end up spending most of their time not learning physics but building tools. Most notable among these are tools that are actually not experimental but theoretical. It’s not sufficient for an experimental physicist to be good at building magnetometers, wiring circuits or writing software; she also needs to understand the theory that her efforts are going to test, as well as the limitations of her efforts in validating essential features of the theory.

There are a handful of experimental physicists in the 20th century who straddled this boundary with ease. Supreme among these was Enrico Fermi, whose achievements in both theory and experiment were unparalleled. The historian of science C P Snow paid Fermi the ultimate tribute when he remarked that, had Fermi been born twenty years earlier, he could have seen him first discovering Rutherford’s atomic nucleus and then inventing Bohr’s theory of the hydrogen atom. That’s as high as praise can get. However there were other physicists who were also quite accomplished in both domains. One example was Isidor Rabi who knew enough theory to interpret the results of his Nobel Prize winning magnetic beam experiments. Another was Willis Lamb, a student of Robert Oppenheimer whose precision experiments on the energy levels of electrons in hydrogen atoms led to observation of the so-called Lamb Shift. The Lamb Shift was the starting point for a revolution in physics that led to the theory of quantum electrodynamics.

In other sciences too it is important for practitioners to understand enough of other tools and ideas to have an impact. Chemistry being a more experimental science compared to physics, it’s especially important for chemists to remember Blackett’s motto. For instance a biochemist might be exceedingly accomplished in setting up assays to test the activity of a drug, but he might likely misinterpret results or not follow up on interesting ones if he is unaware of kinetics, thermodynamics and the principal features of intermolecular interactions. Similarly, a synthetic chemist setting up a reaction needs to be proficient in understanding molecular conformation and the determinants of molecular reactivity. Simply being able to set up low temperature reactions, handle flammable reagents and record NMR spectra won’t be enough.

Perhaps the most important message from Blackett’s musings is that one does not need to truly excel in one domain or another in order to excel in their combination. This principle applies to other fields too. For instance Oliver Sacks, while a very good neurologist, was not one of the top neurologists in the world. Similarly, although an excellent writer, he was perhaps not at the very top of the pantheon of prose stylists. But as Andrew Solomon says in his review of Sacks’s wonderful autobiography, what made him truly unique was the fact that he was a very good neurologist who was also a very good writer. It was this killer combination that made him world-class.

In this era of highly interdisciplinary research, Blackett’s message should be especially pertinent. With the constant river of diverse data flowing toward us at superhuman speed, it’s probably a bad strategy to try to excel in multiple fields all at once. Instead, just like Blackett’s ideal experimental physicist, it’s far better to aim for being pre-eminent in knowing those fields in the first place, and knowing enough of each to be useful and not dangerous.

Lessons on management styles from Edward Teller, Hans Bethe and Robert Oppenheimer: A question of temperament

Oppenheimer entertaining at Los Alamos. He could be a
wonderful host.
March, 1943. War is raging across the European continent. The Nazis have faced two significant drawbacks in their relentless quest for racial and geographical conquest - one at El Alamein in North Africa and the other at Stalingrad in the Soviet Union - but Hitler's war machine shows no sign of stopping.

Meanwhile, halfway across the world, the largest and most secret scientific project in history is underway. A laboratory high up in the New Mexico mountains is being staffed with some of the world's best physicists, chemists, engineers, army officers and other personnel. Its express purpose is to build an atomic bomb before Hitler's scientists do so. The brilliant, conflicted Robert Oppenheimer, a polymath equally at home with nuclear physics and Sanskrit poetry, has been chosen to lead the project. He has tapped universities, industrial laboratories and other institutions across the country, recruiting the wealth of brilliant emigre scientists who have fled Nazi Germany for new shores; Adolf Hitler's greatest gifts to the United States. His well known powers of persuasion are on full display as he convinces friends and colleagues to join a secret project whose details he cannot yet fully divulge.

At the top of the list of scientists who Oppenheimer wants to recruit are the Hungarian-born Edward Teller and the German-born Hans Bethe. Both have arrived in the United States during the early 1930s and are now firmly ensconced in their scientific homes - Teller at George Washington University and Bethe at Cornell University. Both men who are still in their late 30s have already made significant contributions to physics. While Teller is more comfortable contributing to the more molecular and chemical aspects of the field, Bethe has uncovered the puzzle to one of science's oldest puzzles - the source of energy in the sun. Both men have been close friends for almost a decade, and Teller has been best man at Bethe's wedding. When the war started the duo wanted to help with the country's war effort, and even though they then lacked a security clearance, worked together on a theory of shock waves (ironically, the paper was classified after it was published, thus closing off access to its own authors).

Teller has also been one of the select key people responsible for sounding the alarm and alerting the government to the potential destructive applications of nuclear fission. Before Oppenheimer and Bethe had fully grasped the implications of a nuclear chain reaction, Teller had already driven his friend, Leo Szilard, to Albert Einstein's summer home in Long Island for what turned out to be a fateful meeting. Szilard had convinced his old friend Einstein to draft a letter to President Franklin Roosevelt; that letter had set the wheels of our nuclear future rolling toward their uncertain destination. Teller is thus one of three or four people, mostly Hungarian emigre scientists, to have been in the loop since the beginning as far as nuclear weapons are concerned. Along with Bethe, he has also been part of a summer study in Berkeley in 1942 led by Oppenheimer in which a handpicked group of physicists worked out the preliminary principles of a fission bomb. More than almost any other scientist and certainly more than Oppenheimer and Bethe, Teller has lived with the bomb since 1939. In fact Bethe did not even believe in an actual bomb until Teller showed him Enrico Fermi's famed nuclear reactor at the University of Chicago in late 1942.

Now, in March 1943, Oppenheimer is in the process of making some key strategic decisions that would shape the organization of the Manhattan Project. Among these decisions, few are as important important as deciding who to put in charge of the theoretical physics division at Los Alamos. It was theoretical physicists who first worked out the feasibility of a nuclear chain reaction, and it would undoubtedly be theoretical physicists who would continue to play a foundational role in the success of the project.

Teller, having lived and breathed the bomb, having contributed to both its politics and its science, having seen the vision of its even more powerful descendant (a bomb drawing its energy from nuclear fusion), thinks of himself as a logical choice to head the division.

Oppenheimer instead picks Bethe. It's an omission Teller will not forget.

The decision would have far-reaching consequences for the organization of the Manhattan Project. It would sow the seeds of discontent that would fracture the community of American physicists a decade later. And it would drive home the interplay between management philosophies and the mechanics of complex technological projects that is relevant to this day.

Why did Oppenheimer pick Bethe instead of Teller, and what does this decision say about his own management style and about those of Teller and Bethe? Teller and Bethe actually shared similar backgrounds. Both were born in the early years of the 20th century to cultured and educated middle class parents in Hungary and Germany. Both were seized by a passion for mathematics and physics, and studied the subjects under two world-class masters of the trade: Teller with Werner Heisenberg in Leipzig and Bethe with Arnold Sommerfeld in Munich. Coming as they did from enlightened Jewish families, both became ominously aware of the noose of fascism tightening around Germany in the early 1930s, and left for the United States where they established leading centers of physics research and study. 

Unlike many American scientists who had led relatively tranquil lives until then, Teller and Bethe were acutely sensitive to the spread of totalitarian regimes, and they grasped the political implications of the chain reaction before many others. But Teller who had seen both Nazi and Communist occupations was the more sensitive of the two, and this awareness led him to be an early proponent of American dominance in nuclear weapons. It was at a conference organized by Teller and his fellow physicist, Russian emigre George Gamow, that Niels Bohr brought news of fission to American shores at the end of 1938.

But there the similarities between the two physicists ended, and it was their differences that led to their very different and fateful life trajectories. Throughout his life Teller was known to be as volatile and moody as brilliant. He was often short-tempered and brooding and could not always be relied upon to carry calculations to their fruition; while to be fair to him he fully recognized this quality, most of his papers were with collaborators who made sure his calculations were fully fleshed out and correct. Teller later classified physicists as 'brick builders' and 'bricklayers', and called Bethe a 'builder of tiny bricks'. In his view his own skills as well as those of Oppenheimer were more suited to bricklaying. Interestingly, both men's bricklaying was more inspired than thorough, brilliant than always right. Their personalities too shared commonalities: both of them could be sharp-tongued, vicious and unpredictable, charming at one moment and cold at another.

Bethe in contrast was one of the most thoroughgoing scientists of the twentieth century, a steady rock of Gibraltar in both science and life. He could meticulously carry through every task to completion; in the 1930s he single-handedly authored a comprehensive survey of nuclear physics running to hundreds of pages that was so all-encompassing and up to date that it became known as 'Bethe's Bible'. He was also a universalist who could solve problems in almost any branch of pure or applied physics. Renowned for ploughing ahead through obstacles and going straight for the solution, his colleagues fondly called him "The Battleship". Stability and wholeness exemplified his personal and professional lives. Unlike Oppenheimer and Teller he was almost always mild-mannered and diplomatic, gentle if firm in his opinions.

Bethe (second from left) on a weekly mountain hike at
Los Alamos with other scientists such as Enrico Fermi.
Given these highly desirable personal qualities, it should come as no surprise that Oppenheimer picked Bethe instead of Teller to head the theoretical division. Bethe's take on the decision recognizes Teller's contribution but also drives home the requirements of the project at this stage and Bethe's suitability for these requirements.

"That I was named to head the division was a severe blow to Teller, who had worked on the bomb project almost from the day of its inception and who considered himself, quite rightly, as having seniority over everyone then at Los Alamos, including Oppenheimer. I believe I was chosen because my more plodding but steadier approach to life and science would serve the better at that stage of its development, where decisions had to be adhered to and detailed calculations had to be carried through, and where therefore a good deal of administrative work was inevitable...I believe Teller resented my being placed on top of him." 

Teller's assessment of Oppenheimer's choice is unsurprisingly critical: "Bethe was given the job to organize the effort, and in my opinion, in which I may well have been wrong, he over-organized it. It was too much of a military organization, a line organization."

Considering the fact that an explicit military style organization was rejected by Oppenheimer and weekly open seminars were set up to avoid compartmentalization, it's hard to substantiate Teller's opinion. Moreover, there is no evidence that Bethe's leadership of the theoretical division was anything but highly accomplished. Implosion, computing, the gun-type bomb design; everything proceeded smoothly under his direction, and during the process he also led outstanding theorists like Richard Feynman, Stan Ulam and Robert Serber.

Feeling sidelined by Bethe's appointment, nursing his passionate dream of a fusion weapon, increasingly loathe to do the kind of detailed calculations that Bethe's group was good at, Teller finally asked Oppenheimer to relieve him of his position in Bethe's division. He spend most of the rest of the war largely thinking about what became the hydrogen bomb. Unlike Bethe's role, Teller's role at Los Alamos was not indispensable. He made some valuable contributions in calculating the behavior of imploding plutonium cores at superdense pressures, but beyond this he seems to have mainly focused on his pet project and kept half a dozen Nobel Laureates awake at night by playing the piano.

Teller was an accomplished pianist
Strikingly, the one thing that stands out even from the embittered Teller's view of Los Alamos is his outstanding paean to Oppenheimer's leadership. Especially considering his growing animosity toward Oppenheimer and the general resentment he must have felt, this tribute is nothing short of profound and speaks to Oppenheimer's extraordinary role in making Los Alamos work.

"Throughout the war years, Oppie knew in detail what was going on in every part of the laboratory. He was incredibly quick and perceptive in analyzing human as well as technical problems. Of the more than ten thousand people who eventually came to work at Los Alamos, Oppie knew several hundred intimately, by which I mean that he knew what their relationships with one another were and what made them tick. He knew how to organize, cajole, humor, soother feelings - how to lead powerfully without seeming to do so. He was an exemplar of dedication, a hero who never lost his humanness. Disappointing him somehow carried with it a sense of wrongdoing. Los Alamos's amazing success grew out of the brilliance, enthusiasm and charisma with which Oppenheimer led it."

Not a bad tribute to a man who, when he was appointed to lead the project, left almost everyone astonished and dismayed because of his lack of experience. A man who had not even led a university department and who, in the words of one of his eminent colleagues, was "not fit to run a hot dog stand." A man who lacked a Nobel Prize but who was asked to lead a group of the world's most brilliant physicists, many of whom would either win or had already won a Nobel Prize. And yet Oppenheimer seems to have blown everyone away, and this includes men like Bethe and Fermi who were far from easily impressed; Bethe said that Oppenheimer was "intellectually superior" to everyone at Los Alamos.

Physicist Victor Weisskopf also attested to Oppenheimer's quality of instantly comprehending everyone's problem, inspiring them and seemingly being everywhere at once:

"He did not direct from the head office. He was intellectually and physically present at each decisive step. He was present in the laboratory or in the seminar rooms, when a new effect was measured, when a new idea was conceived. It was not that he contributed so many ideas or suggestions; he did so sometimes, but his main influence came from something else. It was his continuous and intense presence, which produced a sense of direct participation in all of us; it created that unique atmosphere of enthusiasm and challenge that pervaded the place throughout its time."

Oppenheimer's quintessential quality in doing all this seems to have been that of an actor, a man who could always wear whatever role history had chosen for him like the finely tailored three piece suits which his wealthy New York father's trust fund allowed him to indulge in. Some of his qualities had been on display when he was a highly regarded professor at Berkeley. It seemed he was acutely tuned to the wishes of everyone in the room. His martinis were spicy and his parties famous for their joie de vivre, and his immensely wide knowledge of esoteric subjects like Sanskrit and 17th century French poetry mostly seemed to amplify his charisma. There were a few people who found him pretentious, but these were in the minority; his students emulated his mannerisms. At Los Alamos he was at the peak of his powers, and his instant grasp of every technical and human matter, lightning fast mind and ability to connect with everyone's problems seem to have charmed even Edward Teller.

When the war ended, Bethe, Teller and Oppenheimer went their own ways. Oppenheimer carried over his Los Alamos charm to the leadership of the Institute for Advanced Study in Princeton, where he presided over the likes of Einstein, Godel, and von Neumann. Unfortunately the same powers of persuasion that had been so effective at Los Alamos did not work so well in Washington's corridors of power. Oppenheimer made enemies among politically well-connected men who accused him of hindering the country's hydrogen bomb program. Their unconstitutional tactics and allegations of guilt by association combined with his own equivocation on some of his left wing history and casual arrogance led to a hearing in 1954 and brought about his downfall. He spent the rest of his life speaking out on the philosophy of science and on the relationship between science and society, still efficiently leading the Princeton institute and evoking admiration around the world.

Bethe spent the rest of his career - all 60 years of it - at Cornell University. In the process he elevated Cornell to a world center of physics, advised half a dozen presidents on nuclear arms control, and kept on doing significant scientific work well into his 90s. The same qualities of steadfast stability and integrity that had been on display before served him exceedingly well during the politically tumultuous times of the Cold War and gained him the admiration and loyalty of scores of friends and colleagues. Just like Oppenheimer, he became a wise man whose advice fueled and reassured the hopes of others.

Teller's trajectory was less tranquil. He became the century's most vocal proponent of nuclear weapons and spent most of the next decade obsessing over the hydrogen bomb. He started a rival laboratory which competed with Los Alamos in building the next generation of lethal nuclear weapons, and his own brand of volatile proselytizing drew the admiration of a select group of mostly right wing scientists and politicians. Like Bethe he became advisor to conservative presidents and was a key force in advocating the ill-fated 'Star Wars' weapons system during the Reagan administration's tenure. Most importantly, his fateful testimony against Oppenheimer during Oppenheimer's security clearance hearing was considered an act of betrayal by the majority of the scientific establishment. While Teller lost many of his friends as the result of his testimony, this also allowed him to shed past aspects of his life and make new friends who were more sympathetic to his cause.

By most standards Teller with his volatile temperament and inability to carry projects through to their conclusion should have been largely unsuited for leadership. And yet there was another side of him, a side that could charm and display loyalty. This side could allow him to occasionally perform the function of inspiring others which most of us expect from a good leader. It was a side that was on full display when he became part of a team put together to design an intrinsically safe nuclear reactor, one whose safety features would depend not on the IQ of the operator but on the natural laws of physics. Teller was not technically the leader of the team. The leader was a physicist named Frederic de Hoffmann who along with Teller, recruited other brilliant scientists like Freeman Dyson.

In his biography, Dyson praised the fun and inspiration that Teller brought to the project. He had interacted with Teller at the University of Chicago before and liked Teller's playful attitude toward physics; Dyson thought Teller was a man who did physics for fun rather than glory. That attitude seemed to be particularly visible during the reactor project.

"Working with Teller was as exciting as I had imagined it would be. Almost every day he came to the schoolhouse with some hare-brained new idea. Some of his ideas were brilliant, some were practical and some were brilliant and practical. I used his ideas as starting points for a more systematic analysis of the problem...I fought with Teller as I had fought with (Richard) Feynman, demolishing his wilder schemes and squeezing his intuitions down into equations. Out of our fierce disagreements the shape of the safe reactor gradually emerged."

What lessons do Bethe, Oppenheimer and Teller hold for present day managers and CEOs? Today's CEOs face the same problem that Oppenheimer faced. They have to direct the work of a large group of scientists and other personnel of diverse skill sets and temperaments. They have to soothe egos and give everyone adequate freedom to pursue their ideas while still constraining them to meet project guidelines. They have to please shareholders and the general public. And they have to do all this without appearing to do so, without giving the impression of being heavy handed and dictatorial.

From Oppenheimer they can learn the value of keeping on top of all aspects of a project, whether managerial or technical, and for being informed enough about the role of every person to assure that person of their importance to the team. Like Oppenheimer at Los Alamos, they also have to inspire people to give their very best and to inject enthusiasm and hope into the work especially when things are not going well. And just like the technical seminars at Los Alamos which encouraged open and free discussion, they have to let everyone voice their opinions.

From Bethe they can learn the vital importance of being technically accomplished even as an administrator, and of the importance of perseverance and meticulousness. One of the laments about the present day pharmaceutical industry for instance is that too often you have CEOs with MBA degrees who have little understanding of the great technical challenges of biotechnology or drug discovery. A Hans Bethe would have combined deep knowledge of the science with a plodding and careful approach to getting things done. In addition he would have combined geniality with a gravity that was inspiring rather than intimidating or depressing. Just like Bethe, the best CEOs would combine technical excellence with outstanding managerial capabilities, and even CEOs without a technical background should learn enough of the technical material to empathize with the scientists in the trenches.

Teller exemplifies a different kind of lesson for today's CEOs. In an age where employees are often supposed to fit a particular mold, Teller provides a refreshing example of someone who constantly tried to think outside the box. People like Teller provide a unique function in an organization by frankly speaking their mind and pushing the envelope on what can be achieved. They are useful in shaking up everyone's conventional thinking and charting new directions. Not all their ideas work, but the ones that do can lead to novel horizons. They need to be guided by good managers like Oppenheimer and Bethe who can make them work harmoniously with other employees. These employees in turn must have the patience to actually implement the ideas of Teller-like minds. As long as the Tellers of the world are not allowed to go rogue, they can actually be valuable additions to all kinds of organizations. What matters is whether there is an Oppenheimer or Bethe to lead the way.

So, what exactly do you do for Evil McSinister Corporation?

Science magazine has an article on one of those ubiquitous, awkward situations that anyone who works for the chemical, pharmaceutical or biotech industry must find themselves in at least once or twice in their careers: having to explain to a suspicious and wary interlocutor why exactly they work for Evil McSinister Corporation that's responsible for so many of the World's Woes. The author of the article documents the experience of a scientist who works for Monsanto:
“It must be hard,” I thought, “having to preface every answer to ‘What do you do?’ with ‘So, uh, here’s the thing.’”
VanderKraats confirmed this suspicion when I spoke with him after the panel. He said that there are a lot of misconceptions about his employer, and that he’s had a few awkward conversations in which he’s had to basically explain that his job—developing algorithms to analyze data about phenotypes and genetics—is not tantamount to throwing baby bunnies into a wood chipper.
“I think we contribute positively to the world,” VanderKraats told me, “but sometimes I still hesitate a little to reveal that in a conversation, because you’re not really sure if the person on the other end is an opponent.”
The article actually touches on a very important ethical dilemma than many scientists face: what do you do when, along with some bonafide positive contributions that it's making to the economy and to society, your company is also clearly engaging in some activities that would make even the most ethically hardened soul cringe? News about DuPont, Pfizer and a host of other corporations during the last few years has not done much to bolster the public's faith in these entities. 
Tragically though, the real good that some of these organizations have done along with the sheer complexity and challenges of the research that they are engaging in are two themes that somehow don't seem to filter as much to the lay public. No matter how extensively you may philosophize about why drug discovery is hard, the two main questions which you get asked when you mention you do pharmaceutical research are almost always, "Why are drugs so damn expensive?" and "Why do drugs have so many damn side effects"? That latter question is usually a good cue to transition into a succinct explanation of the scientific challenges of drug discovery: how even the basic science of the process is still woefully under informed, how if we knew how to get rid of side effects, we would with every fiber in our being, how the sheer risk and attrition in drug development can kill a compound during the end game, even after it has jumped over every single obstacle, how drug hunters need to have an appetite for risk that surpasses MacArthur's. By this time though, you are hoping that the person grilling you has not moved on to the next target of his or her outrage.
There's no simple answer to this dilemma. But one of the pieces of wisdom that emerges from thinking more about the issue is that it's almost impossible to work for any institution that does not flirt with morally questionable practices. 
After all, nearly every employer is perceived as evil by someone. If you’re in the chemical industry, you’re poisoning the world. If you’re developing medicines, you’re a shill for Big Pharma. If you’re an engineer at an energy company, you hate pelicans. If you’re in academia, you’re sneering at the peasants from your ivory tower. NASA wastes taxpayer money. Meteorologists are always wrong. Every form of energy production sucks. Military scientists love war. Mathematicians are superfluous. None of our results can be replicated, we’re all drawing unsurprising conclusions, and none of us would allow moral concerns to interfere with results.
I’d like to think that scientists have an ethical obligation to ensure that our work does no harm. It’s a credo I stole from the medical students. But at the same time, we can’t be held responsible for every decision our employers make—especially because most of us have very little power at our places of employment.
Indeed. Institutions after all are run by human beings, and human beings are flawed, and some are downright evil. I think that up to a fairly large margin of error, you can't be held accountable for what some of these human beings in your organization are doing as long as you are not complicit in their actions or have no knowledge of their activities. Where one draws the lines in this regard is hard to pinpoint and is an individual decision, although the extremes as usual are easy to identify: if I worked for a company whose senior management regularly ate babies on live television I probably won't have qualms turning in my resignation right away. Similarly if an organization has a serial record of engaging in unethical financial or environmental behavior combined with a shockingly blatant disrespect for its employees' well-being, it wouldn't be hard to strike that organization off your potential employer list.
Anything between those two extremes is up for debate though, especially at the lower end of the scale. So what does one do when asked why his or her organization was recently indicted for poisoning the waters of that pristine river that flows through your town? I think the article has it right in that whatever the reply is, it needs to be honest and balanced. I would be the first one to admit that like other corporations, drug companies do sometimes engage in patently unethical practices. I would make sure to make it known that I strongly believe that those who encourage such practices should be prosecuted proportionately. But I also would equally emphasize the countless lives that have been saved by drugs, the incredible, often heartbreaking complexity of the basic science of drug discovery and in fact the great positive contribution of chemistry and related sciences as a whole to our modern way of life. Or I could just do a George Whitesides.

Two politicians speak out against the Air Force's new cruise missile

There are three key questions that remain unanswered.
First, does the military need a new nuclear cruise missile? In other words, are there any enemy targets we can no longer “hold at risk” using existing nuclear and conventional weapons and the platforms used to deliver them? We are aware of no such military necessity.  
Next, what role does the military intend this weapon to serve? The Pentagon says it would “provide the president with uniquely flexible options in an extreme crisis.” This suggests a lowering of the threshold for nuclear war, a perilous approach that would endanger not only America but allies that we are pledged to protect, like Japan and South Korea.  
Finally, what is the weapon’s cost? The Defense Department and the National Nuclear Security Administration have yet to provide concrete estimates for the program, but the Federation of American Scientists has reported that it could cost as much as $30 billion. At a time when the Defense Department is set to modernize every leg of the nuclear triad, investing $30 billion in an unnecessary and dangerous new nuclear weapon is irresponsible.  
More here...

The point about lowering the threshold of nuclear war is especially important. In the early 2000s there was a lot of controversy about so-called earth-penetrating warheads or 'bunker busters' - low yield nuclear weapons designed to penetrate deep into the earth and destroy hidden bunkers, or 'hardened' targets. 

The problem was that not only was the radioactive fallout from such a strike unacceptably dangerous, but the weapons themselves lowered the threshold for introducing nuclear weapons and would prompt an adversary to act similarly. In another paradox of the nuclear age, less is actually more.

Unifiers and diversifiers in chemistry and other sciences

Dmitri Mendeleev was a rare example of a
unifier in chemistry. Chemistry in general has
benefited more from diversifiers.
On my computer screen right now are two molecules. They are both large rings with about thirty atoms each, a motley mix of carbons, hydrogens, oxygens and nitrogens. In addition they have appendages of three or four atoms dangling off their periphery. The appendage in one of the rings has two more carbon atoms than that in the other. If you looked at the two molecules in 2D - in the representation most familiar to practicing chemists - you will sense little difference between them.

Yet when I look at the two molecules in 3D - if I look at their spatial representations or conformations - the differences between them are revealed in their full glory. The presence of two extra carbons in one of the compounds causes it to scrunch up, to slightly fold upon itself the way a driver edges close to the steering wheel. This slight difference causes many atoms which are otherwise far apart to come together and form hydrogen bonds, weak interactions that are nonetheless essential in holding biological molecules like DNA and proteins together. These hydrogen bonds can in turn modulate the shape of the molecule and allow it to get past cell membranes better than the other one. A difference of only two carbons - negligible on paper- can thus have profound consequences for the three-dimensional life of these molecules. And this difference in 3D can in turn translate to significant differences in their functions, whether those functions involve capturing solar energy or killing cancer cells.

Chemistry is full of hidden differences and similarities like these. Molecules exist on many different levels, and on each level they manifest unique properties. In one sense they are like human beings. On the surface they may appear similar, but probe deeper and each one is unique. And probing even deeper may then again reveal similarities. They are thus both similar and different all at once. But just like human beings molecules are shy; they won't open up unless you are patient and curious, they may literally fall apart if you are too harsh with them, and they may even turn the other cheek and allow you to study them better if you are gentle and beguiling enough. It is often only through detailed analysis that you can grasp their many-splendored qualities. It is this ever-changing landscape of multifaceted molecular personalities, slowly but surely rewarding the inquisitive and dogged mind, that makes chemistry so thrilling and open-ended. It is why I get a kick out of even mundane research.

When I study the hidden life of molecules I see diversity. And when I see diversity I am reminded of how important it is in all of science. Sadly, the history of science in the twentieth century has led both scientists and the general public to value unity over diversity. The main culprit in this regard has been physics whose quest for unity has become a victim of its own success. Beginning with the unification of mechanics with heat and electricity with magnetism in the nineteenth century, physics achieved a series of spectacular feats when it combined space with time, special relativity with quantum mechanics and the weak force with electromagnetism. 

One of the greatest unsolved problems in physics today is the combination of quantum mechanics with general relativity. These unification feats are both great intellectual achievements as well as noteworthy goals, but they have led many to believe that unification is the only thing that really matters in physics, and perhaps in all of science. They have also led to the belief that fundamental physics is all that is worth studying. The hype generated by the media in fields like cosmology and string theory and the spate of popular books written by scientist-celebrities in these fields have only made matters worse. All this is in spite of the fact that most of the world's physicists don't study fundamental physics in their daily work.

The obsession with unification has led to an ignorance of the diversity of discoveries in physics. In parallel with the age of the unifiers has existed the universe of diversifiers. While the unifiers have been busy proclaiming discoveries from the rooftops, the diversifiers have been quietly building new instruments and cataloging the reach of physics in less fundamental but equally fascinating fields like solid-state physics and biophysics. They have also gathered the important data which allowed the unifiers to ply their trade. The upcoming James Webb Telescope and the existing Kepler spacecraft that searches for extrasolar planets are testaments to the richness of both scientific and technological diversity. Generally speaking, unifiers tend to be part of idea-driven revolutions while diversifiers tend to be part of tool-driven revolutions. The unifiers would never have seen their ideas validated if the diversifiers had not built tools like telescopes, charged coupled devices and superconducting materials to test the great theories of physics. And yet, just like unification is idolized at the expense of diversification, ideas in physics have also been lionized at the expense of practical tools. We need to praise the tools of physics as much as the diversifiers who build them.

As a chemist I find it easier to appreciate diversity. Examples of molecules like the ones I cited above abound in chemistry. In addition chemistry is too complex to be reduced to a simple set of unifying principles, and most chemical discoveries are still made by scientists looking at special cases rather than those searching for general laws. It's also a great example of a tool-driven revolution, with new instrumental technologies like x-ray diffraction and nuclear magnetic resonance (NMR) completely revolutionizing the science during the twentieth century. There were of course great unifiers in chemistry too - chemists such as Antoine Lavoisier, Gilbert Newton Lewis and Dmitri Mendeleev who discovered the general laws of chemistry come to mind - but these unifiers have never been elevated to a status seen among physicists. As I described in another post, chemistry is more suited to foxes than hedgehogs. Diversifiers who play in the mud of chemical phenomena and find chemical gems are still more important than ones who might proclaim general theories. There will always be the example of an unusual protein structure, a fleeting molecule whose existence defies our theories or or a new polymer with amazing ductility that will keep chemists occupied. And this will likely be the case for the foreseeable future.

Biology too has seen its share of unifiers and diversifiers. For most of its history biology was the ultimate diversifiers' delight, with intrepid explorers, taxonomists and microbiologists cataloging the wonderful diversity of life around us. When Charles Darwin appeared on the scene he unified this diversity in one stunning fell swoop through his theory of evolution by natural selection. The twentieth century modern synthesis of biology that married statistics, genetics and evolutionary biology was also a great feat of unification. And yet biology continues to be a haven for diversifiers. There is always the odd protein, the odd sequence of gene, the odd tribe that has swapped gender roles or the odd insect with a particularly startling method of reproduction that catches the eye of biologists and anthropologists. These examples of unusual natural phenomena do not defy the unifying principles, but they do illustrate the sheer diversity in which the unifying principles can manifest themselves, especially on multiple emergent levels. They assure us that no matter how much we may unify biology, there will always be a place for diversifiers in it.

At the dawn of the twenty-first century there is again a need for diversifiers, especially in new fields like neuroscience and paleontology. The interplay between diversifiers and unifiers often manifests itself in the tussle between data rich and theory rich fields. Fortunately fields like neuroscience are both data poor and theory poor right now, so there are plenty of opportunities for both camps to work their magic. But key to this success will be the need to cast off the spell of reductionism and realize that diversifiers play on the same field as unifiers. Unifiers may come up with important ideas, but diversifiers are the ones who test them and who open up new corners of the universe for unifiers to ponder. Whether in chemistry or physics, evolutionary biology or psychology, we should continue to appreciate unity in diversity and diversity in unity. Together the two will advance science into new realms.