Saturday, June 18, 2011

Putting the filosophy back into fysiks

How the Hippies Saved Physics: Science, Counterculture, and the Quantum Revival- David Kaiser

Does philosophy have a place in serious science? Many of the founders of modern physics certainly thought so. Einstein, Bohr, Heisenberg and Schrodinger were not just great scientists but they were equally enthusiastic and adept at pondering the philosophical implications of quantum theory. To some extent they were forced to confront such philosophical questions because the world that they were discovering was just so bizarre and otherworldly; particles could be waves and vice versa, cats (at least in principle) could be alive and dead, particles that were separated even by light years appeared to be able to communicate instantaneously with each other, and our knowledge of the subatomic world turned out to be fundamentally probabilistic.


However, as quantum theory matured into a powerful tool for calculation and concrete application, the new generation of physicists in general and American physicists in particular started worrying less about "what it means" and much more about "how to use it". American physicists had always been more pragmatic than their European counterparts and after World War 2, as the center of physics moved from Europe to the United States and as the Cold War necessitated a great application of science to defense, physicists turned completely from the philosophizing type to what was called the "shut up and calculate" kind; as long as quantum mechanics agrees spectacularly with experiment, why worry about what it means? Just learn how to use it. Yet this only swept epistemological questions under the rug.


Curiously, there emerged in the 1970s a quirky and small group of physicists in the Bay Area who tried to resurrect the age of philosopher-scientists. In "How the Hippies Saved Physics", David Kaiser wonderfully tells the very engaging story of this "Fundamental Fysiks" group and how it kept alive some of the deep philosophical questions that had haunted the founding fathers. The "Fysicists" came from a variety of backgrounds, but all of them had been dissatisfied; both by the dismal job market for physicists after the Cold War craze and more importantly by the purely practical approach toward physics which they learnt in graduate school. Interestingly they combined their deep questions about physics with the emerging hippie counterculture of the 60s and 70s and it's pretty clear from the book that they had great fun doing this; after all this was an age when non-conformity was encouraged. Discussions of physics concepts blended seamlessly with Eastern mysticism, forays into LSD-induced mind experiments, New Age workshops at the Esalen Institute in California and meanderings into telepathy, consciousness and parapsychology. Books like Fritjof Capra's "The Tao of Physics" which explored parallels between modern physics and Eastern religions only helped the movement. The small group of physicists was also fortunate to get funding from some unlikely sources, including self-help guru Werner Erhard and even the CIA who was interested in possible connections between ESP and physics. Not surprisingly, mainstream physicists often ignored and sometimes actively condemned such activities

However, as Kaiser describes in this fascinating volume, this ragtag group of countercultural philosopher-scientists achieved at least one crucial goal; they kept questions about the philosophical implications of quantum theory alive at a time when most physicists eschewed and disdained such questions. Gradually, they managed to get a handful of mainstream physicists interested in their philosophizing. Much of the connection of this philosophy to real physics centered about a remarkable result called Bell's theorem which essentially reinforced the spooky properties of quantum systems by showing that information in quantum systems can flow instantaneously between particles. Remarkably, this seemingly otherworldly idea of "quantum entanglement" (which gave some of the founding fathers heartburn) now lies at the foundation of some of the most cutting-edge areas of modern physics, including quantum computation and the new discipline of quantum information science. What was considered far-flung by mainstream physicists and kept alive by the Fundamental Fysiks group is now serious physics for many. In fact, at least a few physicists who put Bell's theorem to experimental test are regarded as candidates for a Nobel Prize (these especially include John Clauser, Alain Aspect and Anton Zeilinger who shared the prestigious Wolf Prize- often a forerunner to the Nobel Prize- in 2010).

In the end Kaiser wants to make the case that by keeping such once-disparaged philosophical concepts alive, the Fundamental Fysicists "saved physics". I am a little skeptical of this claim. They certainly managed to nurture and publicize the concepts, but it was the harnessing of these concepts by "real" physicists who were involved with the nuts and bolts of calculation and experiment that actually saved the concepts and kept them from turning into a purely philosophical mishmash. In addition, a lot of concepts that the New Age physicists bandied about belonged squarely in the realm of pseudoscience and the trend continues; people like Deepak Chopra commit gross violations of quantum mechanics on a daily basis. Unfortunately the line between science and non-science can be thin and one of the most intriguing discussions in Kaiser's book is this so-called "demarcation problem". How does one know if today's philosophy is tomorrow's cutting edge science or just noisy mumbo-jumbo? It's not always easy to say.

Nonetheless, I think Kaiser and the Fysicists make a really great general case for why philosophical questions in science have their own place and should not be rejected. For one thing, they are always fascinating in themselves and demonstrate the endless human quest for meaning and reality; as recent discussions indicate, the philosophical conundrums in physics have been far from answered and continue to be explored through even more bizarre ideas like parallel universes and multiple dimensions. And as this wonderful book shows, at least in some cases these discussions may lead to key advances by influencing mainstream physicists who validate them by subjecting them to the ultimate arbiter of truth in science- hard experiment.

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Friday, March 18, 2011

"Quantum Man"



I still remember the day when, as a kid, I first came across the irrepressible Richard Feynman's memoirs "Surely you're joking Mr. Feynman". Within a few hours I was laughing so hard that tears were coming out of my eyes. Whether he was fixing radios 'by thinking', devising novel methods of cutting string beans in a restaurant or cracking the safes at Los Alamos, Feynman was unlike any scientist I had ever come across. Feynman died in 1988 and James Gleick's engaging and masterful biography of him appeared in 1993. Jagdish Mehra's dense, authoritative scientific biography came out in 1996. Since then there has been a kind of "Feynman industry" in the form of tapes, books, transcripts, interviews and YouTube video clips. While this has kept Feynman alive, it has also turned him into a kind of larger-than-life legend who is more famous in the public mind for his pranks and other exploits than for his science. Most laymen will tell you that Feynman was a brilliant scientist but would be hard-pressed to tell you what he was famous for. It's time that we were again reminded of what most contributed to Richard Feynman's greatness- his science. Lawrence Krauss's biography fulfills this role. You could think of Gleick's biography as a kind of Renaissance painting, an elaborate piece of work where he gets everything accurate down to the eyebrows of the men, women and Gods. Krauss's biography is more like the evocative impressionistic art of the French masters, more of a lucid sketch that brings out the essence of Feynman the scientist.

The biography is essentially aimed at explaining Feynman's scientific contributions, their relevance, importance and uniqueness. Thus Krauss wisely avoids pondering over oft-repeated details about Feynman's personal life. He compresses descriptions of Feynman's childhood, the tragic story of his first wife's death and their extremely touching relationship and his time at Los Alamos into brief paragraphs; if we want to learn more we can look up Gleick or Feynman's own memoirs. What concerns Krauss more than anything else is what made Feynman such a great scientist. And he delivers the goods by diving into the science right away and by explaining what made Feynman so different. Perhaps Feynman's most unique and towering ability was his compulsive need to do things from scratch, work out everything from first principles, understand it inside out and from as many different angles as possible. Krauss does a great job in bringing out this almost obsessive tendency to divine the truth from the source. It manifested itself at a very early age when Richard was cranking out original solutions to algebra and arithmetic problems in school. And it was paramount in his Nobel Prize winning work.

Krauss succinctly explains how this intense drive to look at things in new ways allowed Feynman to do novel work during his PhD with John Wheeler at Princeton in which he formulated theories that described antiparticles as particles traveling backwards in time. Later Feynman also applied the same approach in using a novel method based on the principle of least action to explain the dizzying mysteries of quantum electrodynamics. Krauss does an admirable job in explaining the physics behind these contributions in layman's terms. Feynman's "sum over histories" prescription involved taking into consideration all of the infinite paths that a particle can take when getting from the beginning to the end point. This was a bizarre and totally new way of looking at things, but then quantum mechanics is nothing if not bizarre. As Krauss describes, the moment of revelation for Feynman came in a meeting where, using his techniques and intellectual prowess, he could finish in a few hours a complicated calculation for mesons that had taken another researcher several months. Krauss also narrates how Feynman brought the same freewheeling, maverick approach to thinking about superfluidity, beta decay, the strong nuclear force, gravity and computing and the book contains the most complete popular scientific treatments of Feynman's thoughts about these important problems that I have seen. The approach did not always work (as it did not in case of superconductivity) but it encouraged other physicists to think in new ways. In fact as Krauss lucidly narrates, Feynman's great influence on physics was not just through the direct impact of his ideas but also through the impact of his unconventional thinking which inspired students and other scientists to think outside the box.

As scientifically brilliant as Feynman was, Krauss also does not gloss over his professional and personal flaws and this biography is not a hagiography. Professionally, Feynman's independent spirit meant that he often would not read the literature and would stay away from mainstream interests which his colleagues were pursuing; while this greatly helped him, on more than one occasion it led to him being scooped. At the same time Feynman also did not care about priority and was generous in sharing credit. As for mentoring, while Feynman was a legendary teacher by way of example, unlike his own advisor John Wheeler he left few bonafide graduate students because of his compulsive tendency to solve problems himself. On a personal basis, probably the most shocking description concerns Feynman's womanizing. It's hard to say how much of it is true, but Krauss describes Feynman's affairs with colleagues' wives, his elaborate methods to seduce women in bars and the personal and emotional entanglements his womanizing caused. At least one fact is jarring; apparently when he was a young professor at Cornell, the boyish-looking Feynman used to pretend to be a graduate student so he could date undergraduates. This kind of behavior would almost certainly lead to strict disciplinary action in a modern university, if not something more drastic. In his early days Feynman was also known for not suffering fools gladly, although he mellowed as he grew older. Later on Krauss details Feynman's more publicly known activities, including his bongo playing, nude painting and his famous demonstration of the failure of the O-rings in the Challenger space shuttle disaster. Feynman's absolute insistence on honesty and truth in science and on reporting the negative results along with the positive ones also comes across, and should be a model for modern scientists. The biography does a good job of demonstrating that in science, true success needs fearlessness, determination and an unwavering belief in your ideas.

Ultimately, it's not Feynman's bongos, nude art and relentless clowning that make him a great man. However, since his death, he has often been perceived that way by the public largely due to the industry that has grown up around him. But Richard Feynman was defined first and foremost by his science and his striking intellectual originality that allowed him to look at the physical world in wholly unanticipated new ways. Krauss's biography performs a timely and valuable service in reminding us why, when we talk about Feynman, we should first talk about his physics.

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Wednesday, September 29, 2010

Why the free market is like quantum mechanics

If we were all omniscient and had infinitely fast and perfect computers, maybe we could use quantum mechanics to explain chemistry and biology. In reality, no amount of quantum mechanics can completely explain the chemistry that goes into treating a disease with a drug, baking a cake or making a baby. Why? Because the system is too complicated, and we don't even know all the factors that make it tick yet.

Now imagine someone who has started out with the honest and admirable goal of trying to apply quantum mechanics to understand the behavior of a biological system like a large protein. He knows for a fact that quantum mechanics can account for (a far better word than explain) all of chemistry- the great physicist Paul Dirac himself said that. He has complete confidence that quantum mechanics is really the best way to get the most accurate estimates of various properties for his system.

But as our brave protagonist actually starts working out the equations, he starts struggling. After all, the Schrodinger equation can be solved exactly only for the hydrogen atom. We are dealing with a system that’s infinitely more complex. The complexity forces our embattled savant to make cruel approximations at every stage. At some point, not only is he forced to commit the blasphemy of using classical mechanics for simulating his system, but he has to actually stoop to using empirical data for parameterizing many of his models. At one point he finds himself fighting against the Uncertainty Principle itself!

In the end our hero is chagrined. He started out with the lofty dream of using quantum mechanics to capture the essence of his beloved protein. He ended instead with a set of approximations, parameters from experiments, and classical mechanics-derived quantities just for explaining his system. Prediction was not even an option at this point.

But his colleagues were delighted. This patchwork model actually gave fairly useful answers. Like most models in chemistry, it had some explanatory and predictive value. Even though the model was imperfect and they did not completely understand why it worked, it worked well enough for practical purposes. But this modest degree of success held no sway for our bright young scientist. He stubbornly insisted that if, just if, we had a perfectly fast computer with unlimited accuracy and an infinite amount of time, quantum mechanics indeed would have been spectacularly successful at predicting every property of this system with one hundred percent accuracy. Maybe next time he should just wait until he gets a perfectly accurate computer and has an infinite amount of time.

The preceding parable was narrated to describe what I think is a rather unwarranted swathe of criticism coming from libertarians about the financial crisis during the last few years. For instance see Amit Varma's criticism here which sums up many of the major points. The reasons for the financial crisis are many, probably more complex than quantum mechanics, and society will surely keep on debating them for years. But one of the most common reasons cited by libertarians (usually in the form of a complaint) for the failure of the economy is that we should not blame the free market for what happened because we never got a chance to actually have a free market. If only we got a chance to have a perfect free market, things would be lovely.

Notwithstanding the fact that this argument inches uncomfortably close to arguments made by the most vocal proponents of socialism in the twentieth century (“There was nothing wrong with the system per se, only with its implementation”), I think it’s a little nutty. Maybe a perfect free market wouldn’t have led to the crisis, but that’s like our young chemist saying that infinitely accurate computers and quantum mechanics would not have led to the kind of imperfect models that we get. The problem is really that there are so many practical obstacles in the application of quantum mechanics to a real-life chemical system, that we are simply forced to abandon the dream of using it for explaining such systems. Unless we come up with a practical prescription for how quantum mechanics is going to address these real-life obstacles without making approximations, it seems futile to argue that it can really take us to heaven.

To me it seems that libertarians are ignoring similar obstacles in the way of implementing a perfect free market. What are these obstacles? Most of them are well known. There’s imperfect competition because of the existence of inherent inequalities, leading to monopolies. There’s all that special interest lobbying, encouraged by politicians, which discourages true competition and allows monopolies to get a head start. There’s information asymmetry, which simply keeps people from knowing all the facts.

But all these problems are really part of a great problem- human nature itself. All the obstacles described above are basically the consequence of ingrained, rather unseemly human qualities- greed, the lust for power, the temptation to deceive, and a relentless focus on short term goals at long term expense. I don’t see these qualities disappearing from our noble race anytime soon.

Now sure, I think we can completely agree that the free market was invented to curb some of the worst manifestations of these qualities, and it has worked remarkably well in this regard. Remarkably well, but not perfectly so. Maybe libertarians need to understand that the last vestiges of the dark side of humanity cannot be done away with, since they are an indelible part of what makes us human. So unless they come up with practical ways in which they can surmount these obstacles, in which they can solve the problem of human nature itself- a difficult goal to put it mildly- it’s rather futile to keep on chanting that all our problems would be solved if only we could somehow make these inherently human qualities disappear.

The final argument that libertarians usually make is; just because there are obstacles in the way of a goal (the perfect free market) that may seem even insurmountable, that does not mean we should not keep on striving towards the goal. I think that’s perfectly laudable. But the problem is, unless you come up with a practical solution for all the problems that you face on the way, your goal is just going to remain an abstract and unworkable ideal, not exactly the kind of solution that's desirable in the practical fields of politics and economics. More importantly, all this striving towards the goal may create problems of its own (the science analogy would be unimaginably expensive calculations, scientists laid-off because of the lack of results, overheating of the computers leading to fires etc.). We have all seen these problems. There’s the well-known problem of externalities, there’s the problem of unregulated firms getting ‘too big to fail’, there’s the problem of growing income inequality. Surely we have to admit that these are real problems too.

So what should libertarians do? Well, didn’t our intrepid quantum mechanic grudgingly accept the intervention of approximations and parametrizations? These seemed ugly, but he had no option but to use them, since quantum mechanics simply could not solve all the obstacles in his way. Similarly, perhaps free marketers could realize that at least in some cases, government intervention, no matter how ugly it may seem, may be the only way to reach a workable goal. Sure, it may not be the best of all goods, but it could be the least of all evils. What would have happened if our bright young scientist had kept on insisting that he wouldn’t budge an inch if he is forced to use anything other than quantum mechanics? He would have ended up with nothing.

And in economics even more than in chemistry, a model that partly works is better than a model that does not exist. “Sometimes it’s not enough to do our best; we need to do what’s necessary” (W. Churchill)...

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Wednesday, July 14, 2010

The jewel of physics faces the 4% challenge

The size of the proton has shrunk by 4%, or so they tell us. The research which was published in Nature and has created waves apparently interrogated the proton with a much more reliable subatomic entity, the muon, which led to a more accurate result. The result of course testifies to the incredible power of modern science to divine such unbelievably small numbers.

But according to a NYT article, this might mean that the "jewel of physics", quantum electrodynamics, may be in trouble. QED which was developed by Richard Feynman and others is the most accurate theory known to science, and has calculated the magnetic moment of the proton to an accuracy of ten significant figures with respect to experiment. As Feynman himself said, this is like calculating the distance between New York and New Orleans to within the width of a hair.

The present measurement could shake up this success a bit according to the article:
When that new radius, which is 10 times more precise than previous values, was used to calculate the Rydberg constant, a venerable parameter in atomic theory, the answer was 4 percent away from the traditionally assumed value. This means there are now two contradicting values of the Rydberg constant, Dr. Pohl explained, which means there is either something wrong with the theory, quantum electrodynamics, or the experiment.

“They are completely stunned by this,” said Dr. Pohl of his colleagues. “They are working like mad. If there is a problem with quantum electrodynamics this will be an important step forward.”

The late Caltech physicist Richard Feynman called quantum electrodynamics “the jewel of physics,” and it has served as a template for other theories.

One possibility is that there is something physics doesn’t know yet about muons that throws off the calculations.

Or perhaps something we just don’t know about physics. In which case, Jeff Flowers of the National Physical Laboratory in Teddington in Britain pointed out in a commentary in Nature, a new phenomenon has been discovered not by the newest $10 billion collider but by a much older trick in the book, spectroscopy.

“So, if this experimental result holds up, it is an open door for a theorist to come up with the next theoretical leap and claim their Nobel Prize,” Dr. Flowers wrote
In other news, a physicist has postulated that gravity is not really a fundamental force but could be a manifestation of the second law of thermodynamics.

Who said challenges do not abound in modern physics!

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