Field of Science

Ahmed Zewail and the challenges of intercultural chemistry

A few days ago I was reading the fine biography of the Caltech chemist Ahmed Zewail who won the 1999 Nobel Prize in chemistry for his wonderful work on laser femtosecond spectroscopy which allows us to literally peer into the secret lives of molecules.

The book and the associated Nobel Prize website biography are instructive because they document in fond detail the inculturation of a highly talented and aspiring immigrant in the United States - an experience that has been shared by hundreds of millions of people since the founding of the Republic.

As Zewail details however, applying deeply ingrained, familiar-as-day cultural quirks in a new environment is not always successful.

"Arriving in the States, I had the feeling of being thrown into an ocean. The ocean was full of knowledge, culture, and opportunities, and the choice was clear: I could either learn to swim or sink. The culture was foreign, the language was difficult, but my hopes were high. I did not speak or write English fluently, and I did not know much about western culture in general, or American culture in particular. 
I remember a "cultural incident" that opened my eyes to the new traditions I was experiencing right after settling in Philadelphia. In Egypt, as boys, we used to kid each other by saying "I'll kill you", and good friends often said such phrases jokingly. I became friends with a sympathetic American graduate student, and, at one point, jokingly said "I'll kill you". I immediately noticed his reserve and coolness, perhaps worrying that a fellow from the Middle East might actually do it!"
I morosely wonder how this kind of a friendly retort might go down worse today in a post-9/11 world where fear of perceived entities continues to be sold to us by politicians and the media with copious mass appeal; I wonder if someone would be bull-headed enough to ignore such cultural differences and go straight to the authorities. Along the same lines I wonder how those famed World War 2 European emigre scientists, arriving here by the boatloads from openly fascist countries, might have fared in 2014.

I ardently hope their experiences would have been the same; no exaggerated fear of anything real or perceived comes anywhere close enough to deny this country the kind of immensely enriching experiences and dominance in science and other fields that amazingly talented immigrants like Zewail, Fermi, Weisskopf and Chargas have brought.

On Freeman Dyson, cadmium estimation and the joy of chemistry

Cadmium sulfide (the solution has a much
deeper, brilliant yellow color)
Freeman Dyson who is a hero of mine and who I have had the privilege of meeting at length several times is someone who has done a lot of interesting things during a long and fruitful life. Not only has he made brilliant, foundational contributions to many areas of mathematics, physics, engineering and astronomy but he has also written books showcasing elegant, wide-ranging, poetic prose.
If you look at Dyson's astonishingly diverse writings or talks it is easy to mistake him as a philosopher of science, a big picture thinker striding on the widest possible canvas.
But as he himself said to me during a long, one-on-one, intellectually sparkling lunch discussion last year, a lot of people think that talking about the big picture automatically makes one a philosopher. Dyson has indeed written about an amazing variety of big picture topics, from the origins of life to the colonization of space. But he also maintains that he has always been first and foremost a problem solver, someone who is much more interested in details than in grand theorizing. Whatever philosophy he manages to weave is built on a foundation of solving specific technical problems. This is partly evidenced by his work on highly technical engineering projects ranging from nuclear spaceships to nuclear reactors.
This quality would make Dyson quite comfortable in the company of chemists, since chemistry by its very nature is more a problem-solving discipline rather than a philosophical pursuit like cosmology or evolutionary biology. I was curious to know Dyson’s views on chemistry since while he has had thoughts on almost every imaginable topic, I could not really find anything by him on chemistry except for a review in Physics Today of Nobel Laureate Roald Hoffmann’s fine book “The Same and Not the Same”.
Then I remembered an excellent collection of interviews with Dyson that I found a few years ago on a website called Web of Stories. This website is a must-see for history of science enthusiasts. It features interviews with scores of famous scientists, humanists and artists from diverse disciplines. These interviews are real gems. The best thing about them is that they are long and detailed instead of two minute sound bytes; each interview lasts in total for several hours and covers most significant events in the interviewees’s life, so you get a real feel for the life and work of leading thinkers. In one of Dyson’s interviews I was delighted to find this:
“I was going to say about chemistry that Roald Hoffmann whom I got to know quite recently, who is a chemist who writes poetry and is a great character, he has the same attitude toward chemistry that I do. I mean it is the beauty of the details rather than any over-arching theory. In that way it’s very different from physics, and I had a taste for it. My taste is always more for the details than for the big picture…
…I learned chemistry from Christopher Longuet-Higgins who was already much more of an expert and more excited about chemistry than Eric James (Dyson’s chemistry teacher at Winchester College). And I remember Christopher bringing to Winchester some crystals of stannic iodide which he had made, which is the most marvelous stuff. It is a brilliant scarlet colour and it makes these beautiful scarlet crystals, and they’re also extremely heavy. If you have a little bottle full of it, it feels like lead. So that kind of chemistry I found delightful, just the sort of details of the actual stuff, rather than the theory that lay behind it.
I remember the joy when, here in Princeton, Willard Libby came on a visit once and brought along another little bottle of chemicals, which also was very heavy, and that was barium xenate, which was barium xenon oxide, which of course was an absolute revelation because nobody imagined that xenon could have compounds, being an inert gas. And it was sometime in the 1950s these compounds were discovered, and barium xenate is just such an ordinary stuff. It’s a sort of heavy white crystals which are completely stable, they don’t show any signs of anything strange and there it is. If you heat them up of course the xenon comes bubbling off…”
So there, I think Dyson would have felt right at home as a chemist. Chemists revel in solving particular problems. It’s not that they don’t care about general principles. Every once in a while someone like Linus Pauling or Alfred Werner comes along and ties together disparate threads into a neat superstructure. But the vast majority of chemical work consists of celebrating the diversity of structure and function inherent in natural and synthetic molecules. The point Dyson makes is an obvious and important one that is often lost among the clich├ęd caricatures of chemists bubbling frothy liquids and crystallizing colorful solids that one often sees in literature and cinema. But it’s precisely these bubbling liquids and colorful solids that endow chemistry with a palpable reality that’s often missing from more theoretical sciences.
A personal digression. I remember an episode from an undergraduate chemistry lab where we were supposed to estimate two unknown metal ions from a solution. After trying out every test in the book we could only detect copper. The other ion remained a mystery and we finally threw up our hands. That’s when the instructor revealed his trick. It turns out that the method of copper estimation that we were using involved turning the solution highly acidic with hydrochloric acid. With a smile on his face, the instructor put a single drop of the concentrated acidic solution in a large flask and then filled the flask to the brim with water, diluting the initial solution by at least a factor of ten thousand. Our eyes were glued to the flask as he passed hydrogen sulfide gas into the solution. And then, starting from the bottom and rising to the top, the flask filled up with the most beautiful yellow color that I have ever seen; it’s a sight that I will never forget. What happens is that cadmium is precipitated as cadmium sulfide only in dilute acidic solutions while for copper it’s the opposite. All our tests for detecting copper in concentrated acid missed the hidden cadmium, until it was ready to be unmasked by simple dilution.
Every chemist is familiar with this feeling of discovering something unknown, no matter how trivial or important, that actually exists; all the better if it has a brilliant scarlet or full-throated yellow color, as is often the case in chemistry. Dyson is right that there is something unmistakably reassuring, in-your-face - real – about holding a vial of something that was previously considered impossible.
The great organic chemist Robert Burns Woodward spoke of this very real quality of chemistry that helped him choose between chemistry and mathematics when he was a teenager:
“The fact is that I have always been very fond of mathematics- for one short period, I even toyed with the possibility of abandoning chemistry in its favour. I enjoyed immensely both its conceptual and formal beauties, and the precision and elegance of its relationships and transformations. Why then did I not succumb to its charms? For two reasons, I believe:
FIRST, because by and large, mathematics lacks the sensuous elements which play so large a role in my attraction to chemistry. I love crystals, the beauty of their form- and their formation; liquids, dormant, distilling, sloshing!; the fumes; the odors- good and bad; the rainbow of colours; the gleaming vessels, of every size, shape and purpose. Much as I might think about chemistry, it would not exist for me without these physical, visual, tangible, sensuous things.
SECOND, while in mathematics, presumably one’s imagination may run riot without limit, in chemistry, one’s ideas, however beautiful, logical, elegant, imaginative they may be in their own right, are simply without value unless they are actually applicable to the one physical environment we have- in short, they are only good if they work! I personally very much enjoy the very special challenge which this physical restraint on fantasy presents”
Woodward’s second reason for studying chemistry goes to the heart of the nature of empirical science, what Richard Feynman called “imagination in a straitjacket”. It’s a philosophy that drives all of science including the most rarefied theoretical ideas. Physicists often like to tell the story of how Einstein felt that “something had snapped inside” him when he saw the predictions of general relativity confirmed by observations of the perihelion of mercury. He surely must have felt the rare, once-in-a-lifetime satisfaction of a great theoretical construct being validated by a real observation that could be boiled down to a single number. We tend to think of Einstein as the great scientist-philosopher, but there he was, being ecstatic about a technical detail that was a crucial part of his magnum opus. Observing barium xenate or precipitating cadmium is not quite as momentous as confirming the theory of relativity, but I can readily imagine feeling a shiver down my spine if I had been presented with that sort of chemical evidence. Evidence that seemed to defy the impossible but which I could nonetheless hold in my hand and keep in my closet. That’s the joy of chemistry.
This is an updated version of a previous post on Scientific American.

David Greenglass and Robert Oppenheimer: A lesson from history

David Greenglass and Robert Oppenheimer
(Images: NYT and NDTV)
The name of David Greenglass must have almost completely faded from memory for people of my generation. Greenglass himself probably wanted his name to fade from all of history, although history is seldom so kind. The fact remains that not only did he spy for the Soviet Union on the Manhattan Project but he also likely betrayed his sister and sent her to the electric chair.

Greenglass who died quietly on July 1 at age 92 in a nursing home was the atomic spy who ferried secrets from Los Alamos to his sister and her husband, the infamous Rosenbergs. His obituary in the NYT appeared yesterday and it's interesting not only for the bygone era that it evokes, but even more so because it eerily comes on the heels of another article from the NYT two days ago, this one documenting the release of the complete transcript of Robert Oppenheimer's 1954 security hearing. In death Greenglass and Oppenheimer strangely join hands in teaching all of us some valuable lessons.

Their stories are both instructive tales of misguided priorities and the kind of paranoia and intolerance of freedom of expression that war and peace can both engender. The reason why the simultaneous appearance of stories about these two men is so striking is because it reminded me of one of the greatest ironies of the Manhattan Project: the fact that in spite of what was considered watertight security, Klaus Fuchs and David Greenglass were literally carrying out secrets of the highest importance through the front gate while the director of the project had his phone tapped and was being interrogated about past communist "associations". A greater misapplication of the security apparatus has seldom manifested itself.

Greenglass and Fuchs both gave away key secrets on the implosion design of the plutonium bomb - the only real secret as such that the project unearthed - and they did this under the noses of what was supposed to be one of the most sophisticated and tightly controlled security organizations on the face of the planet. Greenglass's life also indicates how sometimes the most ordinary of men can acquire extraordinary significance in the annals of history: Greenglass was a rather lowly machinist, by all accounts not a very intelligent and well-educated man, who by sheer luck ended up in Los Alamos via Oak Ridge, TN. When his brother-in-law Julius found out where he was working he must have drooled at the possibility of getting his hands on crucial atomic information for the Soviets. Julius convinced Greenglass's sister Ethel to convince her brother to pass on secrets, all in the name of camaraderie with Uncle Joe of course.

After the war, when Klaus Fuchs who was the really significant spy confessed, he implicated Harry Gold, the courier who was the go-between between the Rosenbergs, Greenglass and Fuchs. Gold in turn implicated Greenglass and the Rosenbergs. In 1951, in a kind of plea bargain which would spare his wife and give him a lenient sentence, David Greenglass took the stand against his sister and his testimony played an important part in ending the life of this mother of two. The real sinner seems to have been Julius, and how much Ethel really knew has been debated to this day. Nonetheless, it's clear that the Eisenhower administration wanted to make an example of the Rosenbergs so they were executed in the face of public protests in June 1953. In contrast the far more significant spy, Klaus Fuchs, was released after a mere nine years. One wonders how heavily his role in his sister's execution must have weighed on Greenglass's mind for the ensuing 60 years in that obscure nursing home.

Just a year later the monstrosity that was Cold War paranoia brought about the downfall of Robert Oppenheimer. In what will always be a black, shameful blot on the political history of this country, paranoid right-wing enemies of Oppenheimer had the government conduct a security hearing which interrogated Oppenheimer with the zeal of the Inquisition. In a blatantly unconstitutional travesty of justice his phones were tapped and his lawyers were denied access to critical information under the pretext of national security. The father of the atomic bomb, a man who had given so much to his country and whose actions rendered him far more patriotic than those who were accusing him, left the hearing with his security clearance taken away and his spirit broken. The recent NYT article tells us what we knew for 60 years, that Oppenheimer was wholly loyal and exhibited no more than a sensitive liberal's awakening to experiments with different political philosophies. That it took the government 60 years to reveal the blindingly obvious is an indictment of a system of secrecy and classification which has fed upon itself for so long.

Like Shakespeare's tragedies the stories of both these men are timeless and speak to the ages. Just like it spied on Oppenheimer while letting Greenglass get away, the national security apparatus as revealed by Edward Snowden today spies on innocent people while letting the real criminals get away. Just like McCarthy and his acolytes interpreted disagreement with disloyalty, so do today's political extremists equate disagreement with bigotry and treason. Members of both the right wing and the left often squelch dissenting opinion, either through official or legal means or more commonly through creating enough public outrage so that the opposition is silenced. Both public and private organizations worry about political correctness far more than they do about diversity of opinion. It is easy enough to extol freedom of speech on paper but much harder to uphold it in practice. Especially when it applies to others.

This won't do. In death David Greenglass and Robert Oppenheimer once again remind us of the pillars which should uphold a liberal democracy that prides itself on freedom of speech, and this is a lesson that we should take to heart. The age of McCarthy is always closer than we think.

Who's the world's greatest living chemist?

Roald Hoffmann: My candidate for
title of 'world's greatest living chemist'
Since we have been making lists of Nobel Prize candidates for the last few weeks and since we already have a few lists of "greatest chemist in history", I thought I would ask for a different kind of selection: Who would be a candidate for the title of 'greatest living chemist'?

Now I would be the first one to admit that any kind of 'greatest' list is always fuzzy and subjective, partly because the meaning of 'greatest' can be highly subjective and controversial. But in this particular case I am thinking of criteria that should be generally acceptable. I also realize that I making this list is like a mouse making a list of the world's most eminent cats, but since there are always more mice than cats and the cats don't usually bother to make such lists themselves I think that's ok.

To begin with, the candidate should be a top-notch scientist since otherwise there wouldn't be a point to that word 'chemist' in the title; to gain an idea of who such people may be it might be instructive to run down the list of Nobel Laureates in chemistry or Priestley Medalists. But simply doing outstanding chemistry is not enough since most of us realize (or should realize, ideally) that there is more to good science than just doing good science. With this in mind I am thinking of some other criteria that would qualify someone for that title: for instance; an excellent teaching and mentoring record, memorable contributions to chemistry education and significant service in terms of chemistry outreach. 

That last bit is important and involves things like serving as editor of a major journal, popularizing chemistry or the cause of chemistry and chemists through popular literature and public talks and serving on official commissions, societies etc. Also, it goes without saying that the greatest living chemist is bound to be an older person since even brilliant younger people simply haven't had the time to make such sweeping contributions. This is one of those few times when 'distinguished and gray' would be preferable to 'young and swashbuckling'.

So without further ado, here is a very personal (and short) list of people I would consider good candidates for the title of 'greatest living chemist'.

1. R. B Woodward: Unfortunately he is no more, but I just wanted to put his name down to make the point that if your scientific contributions were of his caliber, you would probably earn the title without ever giving a single public talk or training a single student. But moving on...

2. E. J. Corey: Woodward's Nobel Prize-winning heir in the field of synthetic organic chemistry. The man is a legend in the universe of reagents and products, and for good reason: There is not a single academic, government or industrial laboratory in the world that does not use a synthetic approach developed by Corey's group. When it comes to practical organic chemistry, his achievements to the field surpass that of anyone else, probably including Woodward. 

Corey has also been a phenomenal and unsurpassed trainer of chemists, having trained over a hundred graduate students and two hundred postdocs; his extended family now occupies the nooks and crannies of almost every major chemistry institution. Sadly his career has been marked by a few graduate student tragedies, but in my book the balance of his contributions still eminently marks him as a candidate.

3. Roald Hoffmann: Hoffmann won the Nobel Prize in 1981 but as evidenced just by the list of papers he co-authored this year, he is still making solid contributions more than 30 years later. Hoffmann is also one of those few chemists who seems to be knowledgable in almost every theoretical aspect of the subject; over the years he has authored papers on diverse chemical species ranging from unstable ions to extended inorganic lattices to metal-organic frameworks. 

But what really marks him apart for me are his efforts in the service of the public understanding of chemistry. He has done more to popularize the cause of chemistry and to communicate the essential philosophy of the subject more than any other chemist of his caliber (I reviewed his latest collection of essays here); also importantly, he hosted the TV series "The World of Chemistry". In addition he is a notable playwright and public speaker, and since 2001 has hosted a science cafe in New York City which explores connections between science, art and poetry. These key public achievements, in addition to his prolific chemistry research, catapult Hoffmann to the top of the list on my opinion.

4. Carl Djerassi: Hoffmann's partner in crime when it comes to writing plays and novels, Djerassi has not been any less prolific even though he has given up actual research for a while now. He is of course best known as the father of the pill, and the social and cultural impact of this invention simply cannot be overestimated. In addition he rivals Hoffmann in conducting public readings, writing plays and giving talks on chemistry. His two memoirs ("Steroids Made it Possible" and "The Pill, Pygmy Chimps and Degas's Horse") are eminently readable. Definitely a worthy candidate.

5. George Whitesides: Whitesides is another chemist whose sheer diversity of research may be unparalleled. His lab has worked on everything from the solution structure of lithium cuprates to NMR spectroscopy to scenarios for the origins of life. He has also trained an impressive number of chemists. But Whitesides is also hugely influential on the national and international chemistry scene. He has advised presidents and served on important commissions. Most importantly, his contributions to the cause of chemical education have also been notable. With Felice Frankel he authored a lavishly illustrated book on science at the nanoscale. He has written a highly cited article on how to write a scientific paper. And as I have mentioned in a few posts, many of his review articles go to the heart of what directions chemistry should take and how chemists should communicate the importance of their science to the public. Whitesides is as good a candidate for our title as anyone else.

6. Ronald Breslow: It must not have been easy being Ron Breslow during the last few years. But it shouldn't have been too hard either. If we are really talking about all rounders then Breslow may possibly top the list. As a researcher his fame - dinosaurs notwithstanding - is enormous and wholly well-deserved. He has won almost every prize out there. In addition he has mentored outstanding students who now occupy the leading centers of academic chemistry around the country, and one of them has even won a Nobel Prize. As if all this were not enough, Breslow has served as President of the ACS and has co-authored important official reports about chemistry and chemical education. For his tremendous work as a scientist and all-round educator I think Breslow should be on the list.

So that's my short selection of people for the title of 'greatest living chemist'. Other potential names on the list would be Allen Bard, Jacqueline Barton, Richard Zare, Jack Roberts, Harry Gray, Ken Houk and Martin Karplus. All of these folks demonstrate some notable combination on top-notch research, high quality mentorship and chemistry service and outreach.

All of them and more are eminently deserving, but if I had to really pick one as a personal favorite I would pick Roald Hoffmann. To me his prolific chemical output combined with his passion for exploring the interaction of chemistry with art, poetry and philosophy and then actually communicating these interactions to the public through books and talks set him apart. A rare breed of scientist.

Offer your own suggestions in the comments section!

The demise of ScienceOnline

So it seems that the pioneering science communication conference Science Online is no more. It's a sad piece of news, especially since I attended the conference twice and had registered to attend it again in Atlanta next year.

The news is sad but it's not entirely surprising; in fact I got the first whiff that something might be wrong when I was getting emails asking me to encourage others to register even one week after registration opened (usually registration sells out in minutes). The events from last year undoubtedly tarnished the conference, and I suspect that for a science journalism and writing conference funding is always an issue. The fact that the conference was able to get sponsors and raise funding for a solid seven years is a testament to the abilities of its organizers, volunteers and attendees.

My main issues with the event have been accurately articulated by Chad Orzel on his Uncertain Principles blog; the post is really worth a read if you want to understand what went wrong with this well-meaning and otherwise quite successful gathering. The problem is that during its last few years it seemed like the conference was trying to find its identity, and was stuck in limbo between being a straightforward professional conference and an evening at the bar where the old boys ' and girls' club traded stories and off color jokes. Chad puts it well:
The core issue, I think, is this: Science Online has been trying to split the difference between functioning as a kind of professional society for science communicators and a party of a bunch of like-minded friends... 
It (Science Online) started out as a small gathering of bloggers who happened to be based in North Carolina, and again, my initial impression was that it was basically a party thrown by and for a bunch of people who ran blogs and wanted to hang out with other people who ran blogs. A very informal atmosphere would be totally appropriate... 
In the intervening years, though, roles changed. Science Online moved from being a small get-together for people with blogs to a moderately large conference (around 500 attendees) that’s an important part of the professional life of the people who work in science communication via the Internet.
In other words, ScienceOnline changed rather quickly from being an intimate gathering between friends where certain kinds of jokes, conversations and behaviors were appropriate to a large, professional, straitlaced conference where such behavior would not usually have been considered kosher. However the conference could not quite achieve this transformation and could not let go of its roots, and while these intentions were well-meaning in the sense of embedding both new and old participants in an intimate and highly informal atmosphere, perhaps it did not have a salubrious effect after all, especially on newcomers. Not all newcomers who came to the conference seemed entirely comfortable with an environment that seemed to cross otherwise traditionally set conference boundaries with impunity.
I can attest to this conflicting mix of feelings myself. The first time I attended was in 2010, three years after the conference was inaugurated. I don't remember how many people attended, but it certainly was much less than the 500 or so who have been showing up over the last few years (as an aside, this was also where Carmen Drahl from C&EN encouraged me to start Tweeting, a suggestion for which I have always been grateful to her). I was delighted to put faces to so many names whose achievements and opinions I had only been familiar with until then through their blogs. It did seem like an intimate atmosphere but also one that was very nurturing and welcoming to new people.
The next time I attended was last year, in 2013, when I moderated a discussion on open peer review with Jarrett Byrnes from UMass Boston.  And things seemed to have distinctly changed. The event was much bigger and in one sense it was much more professional. And yet it had acquired a kind of semi-cultish status that I did not sense during my previous attendance. There were clearly some groups of people who had known each other for years and who were privy to a variety of inside jokes and backroom discussions, and they had no problems trading this information among themselves - all of which would have been fine for a group of science-bloggers-turned-friends meeting every Saturday night in a bar, but not really so for a conference that had admittedly turned into the premier conference for all things science online in the country. Unlike 2010, the boundaries between these groups and others seemed to be much more firmly delineated in 2013 and the barriers for inter-group communication seemed higher.
Nobody tried to actively prevent or discourage newcomers from entering this world of inside jokes and longstanding associations, but even I - someone who by then considered myself a fairly well-established member of the science blogging community -  sensed a greater sense of isolation. Part of the reason for this was actually quite positive: While in 2009 the conference had been mainly focused on blogs and websites, by 2013 it had branched into many other diverse and important topics like metrics, general journalistic issues and scientific fraud. All eminently important topics of course, but rather diffuse for people who might have been interested in the original themes of blogs and related topics. However with these positive developments came the negative ones highlighted above.
In one sense ScienceOnline experienced challenges that every conference which quickly grows from a small gathering to a professional event does. In fact one might argue that the very fact that the event grew so quickly and faced these transformational issues is a testament to how popular it became. But it's hard to deny that it could not adapt equally quickly to this transformation. The biggest lesson from this story is that a conference needs to adapt to changing needs and developments without abandoning its core principles, and it needs to do this sooner than later.
In any case, it is also really hard to deny that on balance, ScienceOnline had a huge and mostly positive impact on the science blogging, journalism and research communities. It was really the first and most importance place where like-minded people could finally come together, celebrate their achievements and voice their concerns. Like me, scores of others could put faces to names and interact with people from a variety of disciplines and discuss a variety of issues. We learnt about issues which were quite alien to us before, and we expanded significantly on those which we already knew about.
Ultimately ScienceOnline will serve as a valuable blueprint for everyone interested in the cause of science communication and future such conferences should look at it as a flawed but instructive milestone. This blueprint will benefit immensely from the successes of the event, but also equally from its shortcomings; after all we learn from our mistakes even more than from our triumphs. The organizers of Science Online should derive satisfaction on both these grounds.

Edward Witten, chemistry and the problems with falsification

Science writer and journalist John Horgan who wrote the notorious and thought-provoking book "The End of Science" in the 90s has an interesting interview with theoretical physics giant Edward Witten. Witten, who won the Fields Medal back in the 80s, is widely regarded because of his huge status and influence as one of the main reasons a number of physicists switched to doing string theory in the 90s.

The whole interview is worth reading but there was one chemistry-related response that Witten gave which especially caught my eye:

Horgan: Do you agree with Sean Carroll that falsifiability is overrated as a criterion for distinguishing science from pseudo-science? 
Witten: Scientists aim to get as reliable and precise an understanding of nature as we can.  The gold standard is a precise prediction that can be tested in a precise way in a laboratory experiment.  Experiments that disprove theories are an important part of the scientific process. 
With that said, it is a little too narrow to claim that science consists of trying to falsify theories because a lot of science consists of trying to discover things. (Chemists who attempt a new synthesis could say they are trying to falsify the hypothesis that this new synthesis won’t work.  But that isn’t what they usually say.  People who search for life on Mars could say they are trying to falsify the hypothesis that there is no life on Mars. Again, people don’t usually talk that way.)
I have to give credit to Witten for pointing out the problems with falsifiability in the context of chemistry; in my experience there's not even too many chemists who talk about this rather central aspect of the science. The most prominent one who does is Roald Hoffmann who in his recent collection of essays (which I reviewed for Nature Chemistry) does analyze the issues with using falsifiability as a significant criterion in the philosophy of chemistry. Hoffmann also points to other well-known constructs from the philosophy of science, such as hypothesis testing, as being insufficient guides in understanding the methodology of chemistry.

As both Hoffmann and Witten point out, most chemists when they are trying to make molecules are not really trying to falsify anything, except in the trivial and general sense of trying to "falsify" the basic principles of chemistry. But this fact also goes to the heart of chemistry as a science and art that is more akin to architecture and which really tries to build things rather than simply breaking them down. That is also the reason why, in my opinion, the whole reductionist paradigm has some clear limitations when applied to chemistry; most chemists are really trying to see how emergent molecular properties arise from putting atoms together in different arrangements. Breaking things down in the form of elemental or spectroscopic analysis is of course a reductionist activity that's an essential part of chemistry, but even that process really is in service to understanding how atoms can combine together to give rise to novel structure and function.
It's good to have even physicists like Witten point this out. But it's also something that more chemists and chemistry popularizers should be aware of, especially when they describe their philosophy of doing science to the wider world. Explicating the unique philosophy of chemistry not only sheds light on why chemistry is different in its own way but also demonstrates why we must not hold exalted notions from the philosophy of science like falsification sacrosanct.

The 2014 Nobel Prize in Chemistry and tool-driven scientific revolutions

Last year I wrote a post detailing the views of historian Peter Galison and physicist Freeman Dyson of science as being as much of a tool-driven revolution as an idea-driven one. Now here's a great instance of that tool-driven paradigm change: this year's Nobel prize for chemistry which was awarded to Eric Betzig, Stefan Hell and W. E. Moerner for single molecular techniques, especially single molecule fluorescence microscopy and spectroscopy. The prize has been awarded for a set of techniques - and technological developments - rather than for a groundbreaking idea. But these techniques have led to ideas which hold enormous promise for the future. The recognition thus reflects how ideas and tools feed off of each other in science.

Moerner seems to have been an obvious choice on several people's lists for years while Hell and Betzig seem to have largely escaped attention. 

Here's what the three prizewinners did, in a nutshell:
Two separate principles are rewarded. One enables the method stimulated emission depletion (STED) microscopy, developed by Stefan Hell in 2000. Two laser beams are utilized; one stimulates fluorescent molecules to glow, another cancels out all fluorescence except for that in a nanometre-sized volume. Scanning over the sample, nanometre for nanometre, yields an image with a resolution better than Abbe’s stipulated limit. 
Eric Betzig and William Moerner, working separately, laid the foundation for the second method, single-molecule microscopy. The method relies upon the possibility to turn the fluorescence of individual molecules on and off. Scientists image the same area multiple times, letting just a few interspersed molecules glow each time. Superimposing these images yields a dense super-image resolved at the nanolevel. In 2006 Eric Betzig utilized this method for the first time.
The whole suite of single molecule techniques have huge implications for imaging, tracking and tagging molecules of all kinds, but especially so in biology. The importance of fluorescence and spectroscopy for biology have been recognized for years (as exemplified by the Nobel Prize in 2008 and 2002 for instance) but today's prize brings those techniques together and applies them to individual molecules. The prize is not only eminently well-deserved but heralds several prizes of this sort in the future as these techniques are applied to important and promising areas like neuroscience and drug discovery. In addition it is a truly interdisciplinary recognition bringing together physics, chemistry and biology. Which means that everyone should celebrate (or complain...).

There are a few interesting tidbits associated with the three scientists and their work. It seems like both Hell and Betzig were sort of in the wilderness when they made their original pioneering contributions. Hell was working in Finland, away from the mainstream research centers when he had the idea for beating the diffraction limit. And in a trend that's more common than we think, his 2000 paper on STED was rejected by Science and Nature and accepted in PNAS.

Betzig's story is especially interesting: He left academia in 1996 and worked at his father's machine tool company for several years, developing hydraulic technology which was commercially unsuccessful. But the single molecule fluorescence bug had bitten him too hard to let go, so through a series of ventures - one of which involved building a single molecule instrument with a friend in the friend's living room - he gradually returned back to academia, settling in at the Janelia Research Farm Campus in Virginia. My suspicion is that those years dabbling in technology and industry were exactly what enabled Betzig to develop his engineering acumen and apply it to building the right tools.

It's also interesting to note that both Betzig and Moerner made their original pioneering discoveries in industry - Moerner when he was working at IBM in San Jose and Betzig when he was working in his own private company. I think their stories send a clear message that interesting ideas - and especially their implementation - come quickest when good pure science collides with the kind of good engineering and practical expertise that one is exposed to in industrial settings. I think the 2014 chemistry Nobel Prize recognizes engineering as much as science and this makes it an especially important example of a tool-driven scientific revolution.

In any case, an eminently well-deserved prize with implications that are just starting to be realized and which will undoubtedly scale many new horizons in the future. Congratulations to the three prizewinners!