Freeman Dyson is a unique treasure; he is not only a brilliant and accomplished physicist who has made important contributions to an astonishingly diverse range of topics in physics and mathematics, but he is also one of the very few scientists around who can craft genuinely eloquent prose. His writing is simple, elegant, and enriched by the words of poets, historians and famous literary lights. Most importantly, Dyson evidences in his writings a quality that is extremely rare among scientists: a deep-seated sensitivity to human problems and to the state of the world that reflects sincere humanism. Indeed, he might be the best living example of someone who can reach across both of C. P. Snow's "two cultures". Meeting him at length twice was one of the most memorable experiences of my life.
Dyson's capacity to stride both the natural and the humanities is emblematic of many other contrasts in his personality. A mathematician who is unabashedly at home in the rarefied realms of pure thought, he has also worked on hard engineering problems related to nuclear reactor and spaceship design. He constantly emphasizes that he is a problem-solver and not a philosopher, yet he manages to write superbly on speculative and philosophical topics like the propagation of life across the cosmos. He is almost ninety and looks like a frail wizard, yet he speaks authoritatively, has a solid memory unmarred by age and confidently strides the grounds of the Institute for Advanced study in Princeton with the energy of someone in their twenties. He is unfailingly cordial, shy and avuncular, yet is not afraid to hold back with his opinions. And in most of his writings he demonstrates an endlessly interesting contrarian streak that has led to his reputation as a maverick; one of his best-selling collections of essays is in fact a paean to the rebel streak in science.
All these qualities are on display in Phillip Schewe's biography of Dyson. The biography does a very good job of evocatively narrating key events from Dyson's life and many of the chapters are quite captivating, but I wish it emphasized Dyson's science more. In addition the biographer is somewhat at a disadvantage since Dyson has himself recounted the facts of his life until about 1980 in his wonderful memoir "Disturbing the Universe". Where the reader does benefit from this book is in learning about Dyson's life after 1980 and about parts of his personal life that he has not talked about. A caveat: The volume is not based on interviews with Dyson himself, but it is enriched by interviews with scores of Dyson's family members, friends and colleagues.
Schewe starts with an account of Dyson's upbringing in wartime England where he was raised by upper middle-class parents who were highly educated and socially responsible. His mother was a lawyer and his father was a noted music composer who was later knighted. His mother especially drove home the importance of empathizing with people at an early age. Dyson's intellect and his love for science, languages and poetry developed at Britain's elite Winchester College. At Cambridge University Dyson learnt mathematics and physics from the very best minds including Paul Dirac and G. H. Hardy. Working as a statistician in the Royal Air Force during World War 2 was a formative experience for the young Dyson. It was here that he learnt about the bonds that bind people during difficult times, the capacity of science to inform political and military decisions, and the capacity of politicians to ignore scientific advice.
After the war Dyson came to the United States where his unique talents as a mathematician allowed him to make a key contribution to the then developing field of quantum electrodynamics which deals with the interaction of light and matter; in his own memoirs Dyson has evocatively narrated the story of how he collaborated and argued with leading physicists like Feynman, Oppenheimer and Bethe in formulating his theory. Dyson's accomplishment was to unify two very disparate-sounding theories and to provide an array of powerful mathematical tools that have made their way into the theoretical physicist's standard vocabulary. From a pure scientific viewpoint this contribution stands as his most important one and many think that he should have shared a Nobel Prize for it. The work brought him instant fame, most impressively the offer of a professorship before he a got a Ph.D. and election to Britain's Royal Society at the tender age of twenty-eight.
Yet almost right away Dyson started demonstrating that he was unusual among theoretical physicists in having a very broad variety of interests and abilities He wrote important papers on solid-state physics, pure mathematics, astronomy and particle physics. He started consulting for the defense department and worked for the Arms Control and Disarmament Agency. He embarked on a lifelong interest in speculating on the human colonization of space, and consulted for Stanley Kubrick on his groundbreaking space opera. He found that he had a talent for writing popular science articles. He even wrote articles on finding aliens which immortalized him among science fiction fans as the originator of the so-called "Dyson sphere". Most prominently, he seriously worked on a spectacular spaceship fueled by hydrogen bombs named Orion and an "intrinsically safe" nuclear reactor named Triga. Orion especially was the most exciting time of his life and the project demonstrated his amazing interdisciplinary talents. Schewe also talks about Dyson's involvement with the defense-consulting group called JASON during the Vietnam War when Dyson and a handful of other scientists wrote a report on the futility of using nuclear weapons in Vietnam. This involvement was controversial and underscored to Dyson the conflicts between science and public policy.
The book also recounts several personal aspects of Dyson's life including his divorce, his initially difficult relationship with his son George (a noted writer himself) which has now been mended and the two times when he almost got killed. There are plenty of anecdotes about life in Princeton - including ones regarding affairs - but the thrust of the discussion is to emphasize the freedom that Dyson's institute offered him for exploring his interests. The institute also gave him a front-row seat to cutting-edge research and allowed him to rub shoulders with some of the leading thinkers of the twentieth century. At the same time the ivory-tower environment occasionally engendered a sense of isolation in Dyson and this was partly responsible for his "escape" into other projects in different parts of the country.
From the 80s onwards Dyson focused much more on his outstanding writing career and Schewe succinctly describes this part of his life. Throughout his life Dyson has been a big fan of diversity in all its forms, and he has superbly conveyed this fondness in his books which cover topics ranging from history and literature to politics and engineering. Writing has also provided him with an opportunity to indulge his varied scientific interests, including a solid foray into the field of origins-of-life. Distinguished invited lectures like the Gifford Lectures in Scotland gave him a chance to pen eloquent, clear and wide-ranging ruminations on science for the public. He also started writing thoughtful book reviews for the New York Review of Books, an activity that continues unabated. For his interdisciplinary contributions he received many important awards like the Wolf Prize, the Fermi Award and the Templeton Prize; the latter was awarded for his belief that science and religion can be reconciled and has sparked some controversy. Work on defense-related matters and especially arms reduction also continued and this thinking resulted in a thoughtful and soul-searching book on the nuclear arms race called "Weapons and Hope". He also started writing about the fledgling field of biotechnology which he thinks will soon become "domesticated" just like computer technology did during the last three decades; he has high hopes for the combined success of biotechnology and space technology in human colonization of the universe.
In recent years Dyson has become well known for his skeptical views on climate change. As Schewe says, his opinion on the topic was blown out of proportion by a New York Times Magazine profile in 2009; the fact is that climate change occupies very little of Dyson's time and he himself has admitted that he is not an expert. In addition his views on the topic are in the best skeptical tradition of science which does not regard anyone's word as final (one of Dyson's favorite quotes is the Royal Society's motto; "Nullius in Verba", or "nobody's word is final"). They are a testament to his view that hard consensus in science should never stifle dissenting opinions.
Celebrating his 92nd birthday this year, Dyson continues to be remarkably active. He is involved in research on gravitational waves and on game theory, continues to write, travel, consult and give public talks, and still puts in a full day's work at the institute. Schewe ends by conveying Dyson's reflections on mortality, the future of humanity and on family which he considers all-important. Overall you get an excellent sense for what makes this extraordinary man who he is. There are two main reservations I have about the book. Firstly, Schewe uses a lot of metaphors to make the writing more evocative and interesting and for the most part he succeeds. Some of these are amusing; for instance Dyson's transition from England to Cornell University in Ithaca, NY after the war is compared to Ulysses' voyage to Ithaca after the Trojan War. But comparing Dyson's appeals to have his work on quantum electrodynamics recognized by the bigwigs to the Beatles' song "Please please me" is embarrassing.
However my main disappointment with the book was with its relative lack of discussion of Dyson's science. To be fair Schewe declares upfront that this is a biography, not a science history. But the fact is that all of Dyson's interests flow from his scientific thinking and it seemed prudent to delve into the scientific details. Dyson worked on very interesting projects which are still relevant but Schewe never really gets into their nuts and bolts. For instance he does not discuss what the merits of Orion were, or what experts in the field think of it today as an enabling technology for space exploration. The same goes for Dyson's contributions to nuclear reactor design, a subject of contemporary relevance on which Dyson himself has occasionally written.
There's also relatively little background on the half-dozen scientific topics Dyson worked on, including highly regarded papers on spin waves and the stability of matter. The same goes for details of Dyson's work on pure mathematics. In addition the book doesn't say much from a scientific viewpoint about Dyson's skepticism regarding climate change; it would have been especially interesting to know more about the climate models that Dyson criticizes. Perhaps Schewe could have lifted a page from James Gleick's outstanding biography of Richard Feynman ("Genius") which has extensive discussions of the science. Whatever other talents Dyson has, he is first and foremost a scientist and I thought the biography could have discussed the science more than what it does.
But these limitations do not detract from the book's strengths. The writing is often vivid and transmits a sense of the excitement that Dyson feels for science and its myriad consequences. The sheer range of his interests and accomplishments is overwhelmingly clear, so is his concern for the human race. Overall I would very much recommend the volume as a readable biography of a truly remarkable individual; it gives us a fascinating overview of Dyson's life and thoughts and demonstrates why he is one of the most wide-ranging, accomplished and sensitive thinkers and writers of our time.
What is the probability of a chemist discovering a drug? Is that the right question?
Over on Twitter there has been a lively discussion sparked by a question from C&EN's Lisa Jarvis: What is the probability that a medicinal chemist will discover a marketed drug in his or her career? I have some interest in this question since I happened to directly work with two world-class medicinal chemists who invented/discovered bestselling drugs.
The question is actually more interesting than it sounds since it really goes to the heart of what drug discovery is about. In some sense the question does not have an answer since drug discovery is one of the most multidisciplinary research endeavors humans have created, so it's pretty much impossible for any one scientist to discover any drug except by sheer accident. And yet some of us ventured interesting answers to Lisa's question: My guess was 10%, although I was thinking about someone who was part of a whole team that invented the drug. I would probably degrade that guess to 5% on second thoughts. Derek's guess was "less than 1%" and he was referring to the probability of someone actually synthesizing the drug molecule with their own hands. Chemjobber ventured a similar number.
But these numbers only make the question more complicated. For instance, for better or worse, you may be - and often are - a cog in the wheel of a whole machinery of chemists and other scientists working on a drug project. Sometimes by sheer luck you just happen to make the winning molecule that turns out to have the right properties: any other chemist would have been equally competent to make the same molecule. Does that make you the principal inventor? Most people would say no and they would be right, since such a claim would ignore the massive amounts of background knowledge and thinking generated by your entire team that generously littered the path leading to that particular compound. I would say that at the very least, the lead medicinal chemist who heads the team, coordinates different results and ideas, assigns tasks and holds the big picture in his or her mind is equally responsible for the discovery, as long as they are not playing a purely managerial role.
Judging a chemist as one who "invented" a drug would presumably involve finding him or her cited on one or more key inventions related to the drug. Unfortunately the question about chemists discovering particular drugs being on key patents also highlights the features of what I consider to be an outdated patent system which still talks about "inventions" rather than "ideas". The overhauling of this system is especially pertinent in an age where design in chemistry has become much more important than synthesis. Granted that inventions are more tangible and easy to quantify, but without the set of interdisciplinary ideas that contribute to the discovery of a drug there would be no inventions to begin with. And a vast multiplicity of scientific talent and not just medicinal chemistry is responsible for initiating, assimilating and exchanging this set of ideas.
Yet over the years the patent system has become biased toward chemists because their contribution to "inventions" is easiest to measure. It's worth remembering in this context that the original patent system arose from the system of industrial research in late 19th century Germany in which chemists were the leading, if not the only players. Almost nothing about the rational design of molecules was known then, so all the glory and money went to practical chemists who tinkered with molecular combinations and came up with the right one by pure trial and error. The current patent system has been more or less directly inherited from that rather biased framework. Thus you will seldom find biologists, pharmacologists, crystallographers, toxicologists or molecular modelers cited as frequently on patents as medicinal chemists, and yet their contributions are as or sometimes even more important. For instance, it's increasingly appreciated that the biggest obstacle to the discovery of a new drug in a novel disease area is the lack of reproducible and realistic biology; by this token biologists should be the most important contributors to the discovery of a new drug, and often they are. Yet the problem is that these contributions are also harder to classify as inventions. I think there has been a much bigger recognition of constructs such as molecular models, assays and model organisms on patents in recent times, but chemists who make things with their own hands still have the upper hand.
So what is the probability of a chemist discovering or inventing a drug in his or her career? Whatever the probability is, most people would agree that it is very low because of the role that sheer luck plays in developing a new drug. Some of the most promising candidates in the process fall out at the last minute; conversely some dark horses can emerge to be winners out of the blue. But the path to these winners and losers is seldom the handiwork of a single scientist. Sometimes certain individuals rightly take the stage, and they should be duly recognized. But we should never forget those in the wings, down in the orchestra and up in the light box without whom these individuals would never be standing up there and taking a bow.
Image link
The question is actually more interesting than it sounds since it really goes to the heart of what drug discovery is about. In some sense the question does not have an answer since drug discovery is one of the most multidisciplinary research endeavors humans have created, so it's pretty much impossible for any one scientist to discover any drug except by sheer accident. And yet some of us ventured interesting answers to Lisa's question: My guess was 10%, although I was thinking about someone who was part of a whole team that invented the drug. I would probably degrade that guess to 5% on second thoughts. Derek's guess was "less than 1%" and he was referring to the probability of someone actually synthesizing the drug molecule with their own hands. Chemjobber ventured a similar number.
But these numbers only make the question more complicated. For instance, for better or worse, you may be - and often are - a cog in the wheel of a whole machinery of chemists and other scientists working on a drug project. Sometimes by sheer luck you just happen to make the winning molecule that turns out to have the right properties: any other chemist would have been equally competent to make the same molecule. Does that make you the principal inventor? Most people would say no and they would be right, since such a claim would ignore the massive amounts of background knowledge and thinking generated by your entire team that generously littered the path leading to that particular compound. I would say that at the very least, the lead medicinal chemist who heads the team, coordinates different results and ideas, assigns tasks and holds the big picture in his or her mind is equally responsible for the discovery, as long as they are not playing a purely managerial role.
Judging a chemist as one who "invented" a drug would presumably involve finding him or her cited on one or more key inventions related to the drug. Unfortunately the question about chemists discovering particular drugs being on key patents also highlights the features of what I consider to be an outdated patent system which still talks about "inventions" rather than "ideas". The overhauling of this system is especially pertinent in an age where design in chemistry has become much more important than synthesis. Granted that inventions are more tangible and easy to quantify, but without the set of interdisciplinary ideas that contribute to the discovery of a drug there would be no inventions to begin with. And a vast multiplicity of scientific talent and not just medicinal chemistry is responsible for initiating, assimilating and exchanging this set of ideas.
Yet over the years the patent system has become biased toward chemists because their contribution to "inventions" is easiest to measure. It's worth remembering in this context that the original patent system arose from the system of industrial research in late 19th century Germany in which chemists were the leading, if not the only players. Almost nothing about the rational design of molecules was known then, so all the glory and money went to practical chemists who tinkered with molecular combinations and came up with the right one by pure trial and error. The current patent system has been more or less directly inherited from that rather biased framework. Thus you will seldom find biologists, pharmacologists, crystallographers, toxicologists or molecular modelers cited as frequently on patents as medicinal chemists, and yet their contributions are as or sometimes even more important. For instance, it's increasingly appreciated that the biggest obstacle to the discovery of a new drug in a novel disease area is the lack of reproducible and realistic biology; by this token biologists should be the most important contributors to the discovery of a new drug, and often they are. Yet the problem is that these contributions are also harder to classify as inventions. I think there has been a much bigger recognition of constructs such as molecular models, assays and model organisms on patents in recent times, but chemists who make things with their own hands still have the upper hand.
So what is the probability of a chemist discovering or inventing a drug in his or her career? Whatever the probability is, most people would agree that it is very low because of the role that sheer luck plays in developing a new drug. Some of the most promising candidates in the process fall out at the last minute; conversely some dark horses can emerge to be winners out of the blue. But the path to these winners and losers is seldom the handiwork of a single scientist. Sometimes certain individuals rightly take the stage, and they should be duly recognized. But we should never forget those in the wings, down in the orchestra and up in the light box without whom these individuals would never be standing up there and taking a bow.
Image link
Moore's Law turns 50: The End of the Beginning?
The cost of gene sequencing has surpassed even Moore's Law. |
I have always thought that Moore's Law is one of the most misunderstood and exaggerated articles of faith of our times. It should really be called Moore's Observation, since it was no more than that when Gordon Moore came up with it in the 60s, a time when support for the observation was barely getting off the ground. Since then the observation has been applied to everything from genetics to neuroscience. But it has always suffered from hype, most notably by people like Ray Kurzweil who see the law as some kind of holy harbinger of the hallowed singularity.
There is little doubt that the law has held up quite well for electronics, and as the Nature article makes clear, has been the result of a number of fundamental and unexpected enhancements in technology.
The 1990s called for further innovation. Until then, as transistors became smaller, their speed and energy efficiency increased. But when the components reached around 100 nanometres across, miniaturization began to have the opposite effect, worsening performance. Chip-makers such as Intel, which Moore co-founded, and IBM again looked to basic science to improve the performance of transistor materials. Major help came from condensed-matter physicists. They had known for decades that the ability of silicon to conduct electricity improves substantially when its crystal lattice is stretched — for instance, by layering it on another crystal in which the atoms have a different spacing. Engineers introduced strained silicon into chips in the 2000s, and Moore’s law stayed true for several more years.
And yet as the piece notes, the observation is now approaching limits set by fundamental physics. Only new physics can now possibly circumvent the law. Given all the limitations that it notes the article in fact ends on a rather unwarranted upbeat note.
Stepping outside its traditional domain of electronics, in other areas Moore's observation has clearly been uneven. The cost and speed of gene sequencing for instance has spectacularly circumvented the law, and new approaches in the field might cut down the cost and time even more. There is no doubt that the upheaval in gene sequencing is truly remarkable and should definitely warm the cockles of the hearts of Moorians everywhere.
And yet in other fields the trend hasn't really held up. Drug discovery for instance has become even harder than what it was in the 90s, an observation that is encapsulated by its own depressing moniker - Eroom's Law. Similarly when it comes to battery technology the limitations of the law seem to be clear based on fundamental notions of chemical reactivity and kinetics: this might mean that the vision of a Tesla Model S costing ten thousand dollars might remain little more than a cherished vision for a long time. And let's not even get started on neuroscience where, even if the mapping of neuronal space might follow a Moorish pattern, the interpretation and understanding of this space seem to be poised to proceed at a rate that would put even the glacially slow Eroom to shame. The truth of Moore's observation thus seems to follow the mundane law that there are in fact no laws.
There are several problems with generalizing Moore's Law, but to me the most serious problem is that the law assumes exponential or at least constant and linear growth in knowledge on which new technologies can piggyback. Scientific and technological revolutions seem to follow a Galisonian-Kuhnian alternation in which new ideas give birth to new tools which in turn unearth still newer ideas. This works fine as long as every new tool discovers a fundamentally new layer of knowledge. However this optimistic view is largely a child of the age of reductionism in which reductionist tools (like the microscope and the telescope) gave rise to reductionist ideas (like the genetic basis of heredity and the nuclear atom) and vice versa. We are now past that age and are realizing the walls that reductionism has erected for us in the form of complexity, non-linearity and emergence. Unlike the reductionist tools of the past, we simply don't have a good idea right now of the kinds of emergent tools that will break these barriers and uncover more emergent knowledge. To me it's these limitations of reductionism in the face of emergent complexity that translate into the biggest arguments against the continuing application of Moore's Law to everything.
It is interesting to contemplate the reach of Moore's Law in the next fifty years and wonder how it will look like in 2065 (who knows, I may even be around then to cross-check my words...). I think the general features of the law are going to be exactly what they have been since 1965, wildly successful in certain areas and disappointingly bland in others. That exact mix will determine the impact of the law on the essential features of civilization. Gene sequencing will likely exceed the law for a long time, at least a few decades. Electronics will likely taper off at some point, although quantum computing might provide a slight boost. Neuroscience will likely start obeying the trend, at least in certain narrowly defined sub-applications like individual neuron mapping. But fields like drug discovery and battery technology are likely to run into a wall, one erected both by the fundamental laws of physics and chemistry as well as by our ignorance of the sheer complexity of biological systems.
The ultimate challenge though is understanding. No matter how many genomes we rapidly sequence, transistors we densely pack or neurons we interrogate, the knowledge emerging from all that data is not automatically going to follow Moore's Law. Technology can deliver us information at an exponentially accelerating pace, but the trees of knowledge growing from that information will still be a function of the foibles of the very mind that makes it possible to plumb the depths of the river of data predicted by Gordon Moore in 1965.
Shape vs vibration: Continuous rather than discrete?
There's an article in C&EN by Sarah Everts on a new paper by Eric Block's group at SUNY Albany that throws a rather large stone at the window constructed by Luca Turin's vibrational theory of smell. As readers interested in the topic might recall, it's a saga going on for more than a decade now, and as someone who gave a graduate school seminar on the topic I have a mild but longstanding interest in it. The two positions seems to be firmly staked out: one side declares that smell is because of shape while the other declares that vibration also plays a role.
The new paper does some clever detective work in which the authors express the human musk receptor in kidney cells and expose it to various deuterated and non-deuterated musk compounds (in a nutshell - carbon-deuterium bonds vibrate at a different frequency from carbon-hydrogen bonds, so the receptors should be able to tell that difference if the vibrational theory is right). They found that the receptor is unable to distinguish between these compounds at the molecular level. Since Turin's hypothesis is essentially one at a molecular level this is a serious challenge. In response Turin conjectures whether they might have used the wrong receptor or expressed it in the wrong kind of cells - and the complexity of such systems makes both of these arguments not entirely worth dismissing.
The chemical blogosphere's very own Derek Lowe has some thoughtful remarks in the C&EN article which he distills into a post. Curiously the article does not mention Turin and his co-authors' work on fruit flies clearly distinguishing between acetophenone and deuterated acetophenone. To me that was a rather compelling study, but again one performed on a much 'simpler' system.
Nevertheless, the current work definitely throws a gauntlet in front of Turin's theory, and since the shape theory is well-established with truckloads of evidence on its side, the burden is still on Turin's shoulders to demonstrate the validity of his assertions.
Nobody knows what the truth is in this case right now, which of course makes the issue even more interesting. My own recent take on the shape vs vibration dichotomy is that it might be much less of a dichotomy than we think. There is no reason (except that offered by Occam's razor) to discount the possibility that nature might be using shape some of the time and vibration some of the time. Perhaps it's 80% shape and 20% vibration, or perhaps receptors are actually able to tune the shape/vibration mix depending on the context.
It's worth recalling that smell is a very primitive sense and the primordial environment was filled with a vast, dazzling, confusing complexity of chemical compounds. In the absence of heuristic intelligence, evolution needed to muster an equivalent complexity of physicochemical responses to sample that chemical complexity. To that end we shouldn't really be surprised if it turns out that shape and vibration are not really discrete phenomena but lie on a continuum. Maybe it's like wave particle duality - that convoluted gem of a weird theory where what we see depends on the experiment we choose to perform. Doing those right experiments and nailing down the proportions is going to be the tricky part, and it seems that we are making headway in that direction all right.
Nobelist John Pople on using theories and models the right way
John Pople was a towering
figure in theoretical and computational chemistry. He contributed to several
aspects of the field, meticulously consolidated those aspects into rigorous
computer algorithms for the masses and received a Nobel for his efforts. The Gaussian
set of programs that he pioneered is now a mainstay of almost every lab in the
world which does any kind of molecular calculation at the quantum level.
On the website of Gaussian
is a tribute to Pople from his former student (and president of Gaussian)
Michael Frisch. Of particular interest are Pople’s views on the role of
theories and models in chemistry which make for interesting contemplation, not
just for chemists but really for anyone who uses theory and modeling.
- Theorists
should compute what is measured, not just what is easy to calculate
- Theorists
should study systems people care about, not just what is easy or
inexpensive to study.
Both these points are well taken as long as one understands that
it’s often important to perform calculations on ‘easy’ model systems to
benchmark techniques and software (think of spherical cows…). However it’s also
a key aspect of modeling that’s often lost on people who simulate more complex
systems. For instance the thrust of a lot of protein-small molecule modeling is
in determining or rationalizing the binding affinity between the protein and
the small molecule. This is an important goal, but it’s often quite
insufficient for understanding the ‘true’ binding affinity between the two
components in the highly complex milieu of a cell, where other proteins, ions,
cofactors and water jostle for attention with the small molecule. Thus, while
modelers should indeed try to optimize the affinity of their small molecules
for proteins, they should also try to understand how these calculations might
translate to a more biological context.
- Models
should be calibrated carefully and the results presented with scrupulous
honesty about their weaknesses as well as their strengths.
This is another aspect of theory and modeling that’s often lost in
the din of communicating results that seem to make sense. The importance of
training sets in validating models on known systems is well-understood,
although even in this case the right kind of statistics isn’t always applied to
get a real sense of the model’s behavior. But one of the simpler problems with
training sets is that they are often incomplete and miss essential features
that are rampant among the real world’s test sets (more pithily, all real cows
as far as we know are non-spherical). This is where Pople’s point about
presenting the strengths and weaknesses of models applies: if you are
unsure how similar the test case is to the training set, let the
experimentalists know about this limitation. Pople’s admonition also speaks to
the more general one about always communicating the degree of confidence in a
model to the experimentalists. Often even a crude assessment of this degree can
help prioritize which experiments should be done and which ones should be best assessed
against cost and implementation.
- One
should recognize the strengths as well as the weaknesses of other people's
models and learn from them.
Here we are talking about plagiarism in the best sense of the
tradition. It is key to be able to compare different methods and borrow from
their strengths. But comparing methods is also important for another, more
elemental reason: without proper comparison you might often be misled into
thinking that your method actually works, and more importantly that it works
because of a chain of causality embedded in the technique. But if a simpler
method works as well as your technique, then perhaps your technique worked not because of but in spite of the causal chain that appears so logical to you. A case
in point is the whole field of molecular dynamics: Ant Nicholls from OpenEye
has made the argument that you can’t really trust MD as a robust and ‘real’
technique if simpler methods are giving you the answer (often faster).
- If a model is worth implementing
in software, it should be implemented in a way which is both efficient and
easy to use. There is no point in creating models which are not useful to
other chemists.
This
should be an obvious point but it isn’t always one. One of the resounding
truths in the entire field of modeling and simulation is that the best
techniques are the ones which are readily accessible to other scientists and
provided to them cheaply or free of cost. Gaussian itself is a good example –
even today a single user license is offered for about $1500. Providing
user-friendly graphical interfaces seems like a trivial corollary of this
principle, but it can make a world of difference for non-specialists. The
Schrodinger suite is an especially good example of user-friendly GUIs. Conversely,
software for which a premium was charged died a slow death, simply because very
few people could use, validate and improve it.
There do
seem to be some exceptions to this rule. For instance the protein-modeling
program Rosetta is still rather expensive for general industrial use. More importantly,
Rosetta seems to be particularly user-unfriendly and is of greatest use to
descendants of David Baker’s laboratory at the University of Washington.
However the program has still seen some very notable successes, largely because
the Baker tribe counts hundreds of accomplished people who are still very
actively developing and using the program.
Notwithstanding
such exceptions though, it seems almost inevitable in the age of open source
software that only the easiest to use and cheapest programs will be widespread
and successful, with lesser competitors culled in a ruthlessly Darwinian
process.
A molecular modeler to his beloved (medicinal chemist)
With all apologies to W. B. Yeats
We need new models of popular physics communication
One of the issues I have with Steven Weinberg's list of 13 science books is that they showcase a very specific model of science writing - that of straight explanation and historical exposition. Isaac Asimov was very good at this model, so was George Gamow. Good science writing is of course supposed to be explanatory, but I think we have entered an age where other and more diverse forms of science writing have made a striking appearance. Straight, explanatory science will persist, but in my opinion the future belongs to these novel forms since they bring out the full range of the beauty and pitfalls of science as a quintessentially human endeavor. And since writing is only one form of inquiry, we also need to embrace other novel forms of communication such as poetry and drama.
Why do we need other models of science communication? The problem is best exemplified by popular physics and that is what I will be writing about here. As I have written earlier, one of the issues with today's popular physics writing is that it has sort of plateaued and reached a point of diminishing marginal returns: there are only so many ways in which you can write about relativity or quantum mechanics in a novel way. There are literally hundreds of books on these topics, and yet another volume that clearly explains the mysteries of quantum mechanics to the layman would not be especially enlightening.
Thus, among the most recent science books that buck this trend is one I have truly savored - Amanda Gefter's "Trespassing on Einstein's Lawn". The book breaks new ground by not just recycling cutting-edge facts about the universe but by presenting these facts engagingly in the form of a very charming memoir about a daughter and a father (disclaimer: although I know Amanda in real life I had been entranced by the book before I met her). Amanda's book is among the very best I know in the "scientific memoir" category, and the particular model that she has pursued in the book - that of a non-scientist determinedly and rewardingly threading her way through the evolution of her own scientific interests - is a very fruitful one which others should emulate.
There is also the more familiar model of the scientific memoir written by leading scientists themselves. The best instance of this that I have encountered is Freeman Dyson's "Disturbing the Universe" which combines a world-renowned scientist's way of thinking with a genuine literary flair. Very, very few people lie at the intersection of "highly accomplished scientist" and "highly accomplished writer", and Dyson fits the bill better than almost anyone else. There is also Laura Fermi's delightful "Atoms in the Family" that provides a rare glimpse into her husband Enrico's human side. Among the other physics/mathematics memoirs that I have truly enjoyed are Stanislaw Ulam's "Adventures of a Mathematician", Marc Kac's "Enigmas of Chance" and Emanuel Derman's unique and timely "My Life as a Quant". Also while we are on the subject of memoirs, a fictional memoir that projects great poignancy is Russell McCormmach's "Night Thoughts of A Classical Physicist" which vividly portrays the resignation of a classical physicist in the face of the destruction of deterministic physics by the indeterminism of quantum theory, even as the political landscape in Germany around him itself is mirroring this destruction.
What I find most striking though is a model of science writing in which science intertwines seamlessly with fiction. I am not talking about science fiction here of which there is plenty - instead I am referring to volumes that explain science through fictional devices and characters. This genre is often called 'scientific fiction' to distinguish it from science fiction. One of the best examples of this style that I know concerns two of mathematician John Casti's books. "The Cambridge Quintet" is a work of scientific fiction that brings five leading thinkers - C. P. Snow, Alan Turing, Ludwig Wittgenstein, Erwin Schrodinger and J. B. S. Haldane - together at Snow's residence for a dinner conversation on artificial intelligence. The other book titled "The One True Platonic Heaven" pits a similar set of fictional but plausible conversations between the brilliant minds at the Institute for Advanced Study in Princeton, this time on epistemology and the limits of scientific knowledge. Both books are gems and deserve a wider audience.
Another set of fictional conversations between the founders of quantum mechanics is vividly captured by Louisa Gilder's book "The Age of Entanglement". The book is somewhat unfair to Robert Oppenheimer, but otherwise it's unique. And among more recent volumes, one that I have thoroughly enjoyed is Tasneem Zehra's Husain's delightful "Only the Longest Threads" which explores the origins and philosophy of modern physics in the form of letters between two protagonists set against the background of the discovery of the Higgs boson. The book provides a particularly charming example of the human face of science and the beauty of scientific ideas. However, if animals seem more charming to you than human beings, I would recommend two of Chad Orzel's books, one in which he pitches relativity to his dog and another in which the dog has to be at the receiving end of the mind-bending paradoxes of quantum theory.
Then there are the truly fictional works of science enshrined in the form of plays, poetry and even an opera. The opera is "Doctor Atomic" and it's quite unique - I can never get the image of actor Gerald Finley singing John Donne's "Batter my heart, three person'd God" in his baritone voice out of my mind. My earliest exposure to science in the form of fiction though was through Michael Frayn's wonderful "Copenhagen" which charts an imagined set of conversations between Niels Bohr and Werner Heisenberg during a real encounter between the two in September 1941. Frayn's writing is often poetic and he brings out the parallels between principles from physics and the mysteries of human nature without venturing into New Age territory. Another sparkling play along the same lines is Tom Stoppard's "Arcadia" which explores the beguiling paradoxes of time and thermodynamics. And speaking of time, nothing I know - absolutely nothing - surpasses the sheer lyrical prose and wondrous temporal constructions in Alan Lightman's "Einstein's Dreams".
Ultimately as we know, a picture is worth a thousand words, so we cannot depart from this brief overview of novel forms of physics communication without mentioning the graphic novel. My favorite is probably "Logicomix" which describes Bertrand Russell's obsessive quest for mathematical truth. Then there is the literally scintillating "Radioactive" which brings Marie and Pierre Curie's love and science to life in truly creative graphical form. Jim Ottaviani has been a particularly prominent proponent of embodying physics in comic book form, and among his creations are my favorites "Feynman" and "Suspended in Science". Jonathan Fetter-Vorm's "Trinity" which is about the first atomic bomb test is also definitely worth your time. In one panel graphic novels can sometimes convey the reality of science as a human endeavor more powerfully than entire paragraphs, and I have little doubt that this medium will continue to serve as a potent form of science writing.
This little tour of the myriad faces of popular physics - physics as poetry, physics as drama, physics as fiction, physics as comic characters - brings out the sheer diversity of incarnations that the story of physics and its practitioners can adopt when being narrated to a wide audience. Together they speak to the nature of physics as something real done by real human beings. The image of popular physics as a set of explanations of the wonders of the cosmos communicated through explanatory writing is a valid one, but there is so much to be gained by embedding this image amidst a kaleidoscopic variety of other forms of science communication. It's something we can all look forward to.
Note: As I was putting the finishing touches on this post I became aware of a post by Chad Orzel on Forbes documenting similar novel forms of science writing. Gratifyingly we both seem to hit on some of the same themes.
Why do we need other models of science communication? The problem is best exemplified by popular physics and that is what I will be writing about here. As I have written earlier, one of the issues with today's popular physics writing is that it has sort of plateaued and reached a point of diminishing marginal returns: there are only so many ways in which you can write about relativity or quantum mechanics in a novel way. There are literally hundreds of books on these topics, and yet another volume that clearly explains the mysteries of quantum mechanics to the layman would not be especially enlightening.
Thus, among the most recent science books that buck this trend is one I have truly savored - Amanda Gefter's "Trespassing on Einstein's Lawn". The book breaks new ground by not just recycling cutting-edge facts about the universe but by presenting these facts engagingly in the form of a very charming memoir about a daughter and a father (disclaimer: although I know Amanda in real life I had been entranced by the book before I met her). Amanda's book is among the very best I know in the "scientific memoir" category, and the particular model that she has pursued in the book - that of a non-scientist determinedly and rewardingly threading her way through the evolution of her own scientific interests - is a very fruitful one which others should emulate.
There is also the more familiar model of the scientific memoir written by leading scientists themselves. The best instance of this that I have encountered is Freeman Dyson's "Disturbing the Universe" which combines a world-renowned scientist's way of thinking with a genuine literary flair. Very, very few people lie at the intersection of "highly accomplished scientist" and "highly accomplished writer", and Dyson fits the bill better than almost anyone else. There is also Laura Fermi's delightful "Atoms in the Family" that provides a rare glimpse into her husband Enrico's human side. Among the other physics/mathematics memoirs that I have truly enjoyed are Stanislaw Ulam's "Adventures of a Mathematician", Marc Kac's "Enigmas of Chance" and Emanuel Derman's unique and timely "My Life as a Quant". Also while we are on the subject of memoirs, a fictional memoir that projects great poignancy is Russell McCormmach's "Night Thoughts of A Classical Physicist" which vividly portrays the resignation of a classical physicist in the face of the destruction of deterministic physics by the indeterminism of quantum theory, even as the political landscape in Germany around him itself is mirroring this destruction.
What I find most striking though is a model of science writing in which science intertwines seamlessly with fiction. I am not talking about science fiction here of which there is plenty - instead I am referring to volumes that explain science through fictional devices and characters. This genre is often called 'scientific fiction' to distinguish it from science fiction. One of the best examples of this style that I know concerns two of mathematician John Casti's books. "The Cambridge Quintet" is a work of scientific fiction that brings five leading thinkers - C. P. Snow, Alan Turing, Ludwig Wittgenstein, Erwin Schrodinger and J. B. S. Haldane - together at Snow's residence for a dinner conversation on artificial intelligence. The other book titled "The One True Platonic Heaven" pits a similar set of fictional but plausible conversations between the brilliant minds at the Institute for Advanced Study in Princeton, this time on epistemology and the limits of scientific knowledge. Both books are gems and deserve a wider audience.
Another set of fictional conversations between the founders of quantum mechanics is vividly captured by Louisa Gilder's book "The Age of Entanglement". The book is somewhat unfair to Robert Oppenheimer, but otherwise it's unique. And among more recent volumes, one that I have thoroughly enjoyed is Tasneem Zehra's Husain's delightful "Only the Longest Threads" which explores the origins and philosophy of modern physics in the form of letters between two protagonists set against the background of the discovery of the Higgs boson. The book provides a particularly charming example of the human face of science and the beauty of scientific ideas. However, if animals seem more charming to you than human beings, I would recommend two of Chad Orzel's books, one in which he pitches relativity to his dog and another in which the dog has to be at the receiving end of the mind-bending paradoxes of quantum theory.
Then there are the truly fictional works of science enshrined in the form of plays, poetry and even an opera. The opera is "Doctor Atomic" and it's quite unique - I can never get the image of actor Gerald Finley singing John Donne's "Batter my heart, three person'd God" in his baritone voice out of my mind. My earliest exposure to science in the form of fiction though was through Michael Frayn's wonderful "Copenhagen" which charts an imagined set of conversations between Niels Bohr and Werner Heisenberg during a real encounter between the two in September 1941. Frayn's writing is often poetic and he brings out the parallels between principles from physics and the mysteries of human nature without venturing into New Age territory. Another sparkling play along the same lines is Tom Stoppard's "Arcadia" which explores the beguiling paradoxes of time and thermodynamics. And speaking of time, nothing I know - absolutely nothing - surpasses the sheer lyrical prose and wondrous temporal constructions in Alan Lightman's "Einstein's Dreams".
Ultimately as we know, a picture is worth a thousand words, so we cannot depart from this brief overview of novel forms of physics communication without mentioning the graphic novel. My favorite is probably "Logicomix" which describes Bertrand Russell's obsessive quest for mathematical truth. Then there is the literally scintillating "Radioactive" which brings Marie and Pierre Curie's love and science to life in truly creative graphical form. Jim Ottaviani has been a particularly prominent proponent of embodying physics in comic book form, and among his creations are my favorites "Feynman" and "Suspended in Science". Jonathan Fetter-Vorm's "Trinity" which is about the first atomic bomb test is also definitely worth your time. In one panel graphic novels can sometimes convey the reality of science as a human endeavor more powerfully than entire paragraphs, and I have little doubt that this medium will continue to serve as a potent form of science writing.
This little tour of the myriad faces of popular physics - physics as poetry, physics as drama, physics as fiction, physics as comic characters - brings out the sheer diversity of incarnations that the story of physics and its practitioners can adopt when being narrated to a wide audience. Together they speak to the nature of physics as something real done by real human beings. The image of popular physics as a set of explanations of the wonders of the cosmos communicated through explanatory writing is a valid one, but there is so much to be gained by embedding this image amidst a kaleidoscopic variety of other forms of science communication. It's something we can all look forward to.
Note: As I was putting the finishing touches on this post I became aware of a post by Chad Orzel on Forbes documenting similar novel forms of science writing. Gratifyingly we both seem to hit on some of the same themes.
If computational recipes were like food recipes...
...the menu at Boston's elegant L'Espalier might look something like this.
Maine beef tenderloin: Carrot tagliatelle al ragù, gorgonzola
mornay, sunny side up quail egg, crispy shallots
10 ns molecular
dynamics run: Replica exchange, orthorhombic box, embedded sodium ions, 1 fs
time step, Nose-Hoover thermostat. Happy water molecules. Smooth trajectory.
West Coast King salmon, lightly smoked, with vanilla and
cardamom: faux hazelnut gnocchi and pumpkin juice
New England Induced-fit Docking
protocol: Braised loop resampling, 5A residue movement, multicore run with threading.
Optional polarized force field (add 10 tokens). Error bars.
Honey glazed duck for two with roasted pumpkin, chestnut,
foie jus, smoked chocolate puree and toasted nuts and seeds (add 20)
Multi-ligand conformer
search: Seared 10 kcal/mol energy window. Glazed harmonic potential.
Monte-Carlo dihedral drive (add 20 tokens). Experimental infusion.
Licorice glazed Hudson Valley foie gras with black trumpet mushrooms,
hay ash roasted banana, black sesame and almond-rice milk.
Similarity search:
Shape-based scaffold hopper, optionally paired with electrostatics. Statistically validated (add 50 tokens).
There's a reason they're called computational "recipes".
Top 10 popular chemistry books for the general reader
An aerogel, one of the wonders of modern chemistry described by Mark Miodownik in "Stuff Matters" |
But as usual, the other big limitation of the list is that it contains no chemistry books. This wouldn't be the first time a popular science list has excluded chemistry - chemistry is the black sheep of the sciences when it comes to popular writing, even though modern life would be unimaginable without it, as would the puzzle of the origin of life. Given Weinberg's physics background this is somewhat understandable and it's his personal list after all. However I thought I would add my two cents to the discussion by offering my own modest list of chemical titles which I think would delight and inform the general reader, along with some biomedical research sprinkled in. Feel free to add your own in the comments.
1. Oliver Sacks - "Uncle Tungsten": Oliver Sacks recently wrote a wonderful and poignant editorial in the NYT about his imminent fate, but the good doctor should rest supremely assured. All his writings are memorable and will live on forever, and none so much in my opinion as his delightful romp through the wonders of chemistry as a child narrated in "Uncle Tungsten". I myself grew up experimenting with hazardous chemicals, and so this book resonated with me like few others. The book is a paean not just to the magical world of chemistry as explored by a young and receptive mind but also to a nostalgic and charming time when one could buy a pound of each alkali metal from a hardware store and drop it in a lake to see what happens (as Sacks did).
2. Deborah Blum - "The Poisoner's Handbook": This volume is a riveting account of the sinister side of chemistry, and of human nature in general, as it manifested itself in the heyday of New York City during the Jazz Age. Blum is exceedingly accomplished at bringing out the devious motives of poisoners as they exploited the unique chemistry of each poisoning, and she is also very adept at chronicling the rise of forensic science as it pitted science against murder. Thankfully science has largely won that fight - Blum tells us how. If there's any doubt about how chemistry can come alive and impact society in the most consequential and personal ways, this book should dispel that doubt.
3. Natalie Angier - "Natural Obsessions": Angier's book is a rare example of an underexploited and revealing science genre; what one might call "fly on the wall science". In this case the particular wall belongs to the laboratory of Robert Weinberg at MIT. Weinberg is one of the most important cancer researchers of the past fifty years and his lab has discovered many of the most important genes and biochemical pathways involved in the spread of this diabolical disease. Angier does a really great job of documenting the everyday struggles, passions, pitfalls, blind alleys and triumphs of basic research. Science done by human beings, with all its warts and glories.
4. Barry Werth - "The Billion Dollar Molecule": Another true fly on the wall account, Barry Werth's book would get anyone interested in the fast-paced, high-stakes world of drug discovery and biotech research. It is quite definitely the best and only book I know in which a probing, highly articulate writer was allowed virtually untrammeled access to the secret world of cutting-edge research carried out by a major, upcoming company (Vertex Pharmaceuticals). Werth's prose is breathless, vivid and Promethean and makes the scientists at Vertex alternatively look like Gods descended from Olympus and rock stars at Woodstock. While he takes some poetic license, nowhere else have I seen the real world of highly risky and lucrative drug research and the sheer passion of industrial scientists described with such loving care and attention to detail. A must read, along with its less stratospheric but still readable sequel.
5. Philip Ball - "H2O: A Biography of Water": If I had to single out one writer who consistently produces highly readable books on popular chemistry it would be Phil Ball. Phil has written many excellent books on the world of molecules and his writing covers a remarkable range of topics - from Paracelsus to Chartres Cathedral - but in my opinion none bridges the mundane and the profound as well as his book on that most beguiling, commonplace and enigmatic of substances - water. Phil explores an astounding range of phenomena in which water plays a key role, from the water cycle in glaciers to water in outer space to water at the molecular level in the human body. There is also a great chapter on what Irving Langmuir called "pathological science" which describes in gory detail the polywater controversy. This book is a must have on the shelf of anyone interested in popular chemistry.
6. Sam Kean - "The Disappearing Spoon": Just when I thought that popular chemistry books would not become runaway bestsellers, along came Sam Kean with his chronicle of the fun, swashbuckling and sometimes morbid stories associated with the discovery of key elements. Kean focuses mainly on radioactive elements but he also has delightful chapters on other ubiquitous elements like gallium - which is the subject of the title of the book.
7. S. Venetsky - "Tales about Metals" and "On Rare and Scattered Metals": Speaking of elements, one of the delights of growing up in the 90s was the sudden access to hitherto unavailable literary and scientific gems from one of the former Soviet Union's leading scientific publishing companies, Mir Publishers. I discovered Venetsky's wonderful elemental romp through commonplace but still fascinating metals like gold, tungsten and molybdenum in an old used bookstore as a teenager and was stricken. Venetsky is an absolute delight especially when describing the role of coinage metals like copper and gold in history, and his writings are also liberally sprinkled with myths about these chemical wonders as well as descriptions of uses of elements such as 'rare' earth metals in everyday applications like electronics. Venetsky's book is one of those books which would make any boy or girl grow up to be a chemist.
8. Patrick Coffey - "Cathedrals of Science": Biographies of physicists abound but those of chemists are rare. That is why Coffey's book on the epic lives and rivalries of chemists Gilbert Newton Lewis and Irving Langmuir is very much worth a read. Lewis and Langmuir were both the torchbearers of American chemistry during the 1920s, and both made foundational contributions to the discipline. Coffey is at his best while describing their discoveries and the apportioning of credit for those discoveries that became a sticking point between them, their students and colleagues, many of whom included luminaries like Linus Pauling, Walther Nernst and Svante Arrhenius. A great example of the story of science as a quintessentially human endeavor.
9. Roald Hoffmann - "Roald Hoffmann on the Philosophy, Art and Science of Chemistry": Roald Hoffmann is one of those very few Renaissance Men of science who have won a Nobel Prize, written plays and popular books and contributed original ideas to the philosophy of their discipline. I reviewed this collection of essays by Hoffmann for 'Nature Chemistry' last year. As I describe in that review, Hoffmann is especially adept at telling us how chemistry creates its own emergent philosophy which unmoors itself from its reductionist roots in physics. The book would be worthwhile for this discussion alone, but it also has splendid chapters mulling over the meaning of beauty and elegance in chemistry and the complex face of chemistry when it impacts the environment. A unique contribution.
10. Mark Miodownik - "Stuff Matters: Exploring the Marvelous Materials that Shape our Man-Made world": One of the perpetual complaints that chemists have is that when it comes to popular chemistry, somehow the public manages to achieve the contradictory feat of appreciating chemistry's ubiquitous presence in our everyday life while at the same time completely missing the excitement in the discipline. Mark Miodownik's wonderful new book handily bridges this gap. In a series of revealing chapters dedicated to a range of substances, from the exotic (aerogels) to the utterly mundane and commonplace (concrete), Miodownik brings materials science to life. Imagine writing a book about concrete that treats the substance with the same kind of fascination and wonder that one might treat kryptonium, and you get an idea of what Miodownik's book is like. In one sentence, a role model for what popular chemistry writing should be like.