Thoughts on the scientific method (IV): string theory

This post (sorry for the delay) is the concluding part of a four-part series, the first three parts can be found here, here and here.

To summarise the main points that I argued previously: (i) logical positivism and the criterion of falsifiability are not necessarily appropriate guides to how science should be practised, (ii) the word "theory" is inconsistently used and best avoided in such a discussion. What science does, in practice, is to pursue goals, develop frameworks and formulate models. In applying criteria like testability, verifiability and falsifiability, one needs to keep this classification in mind, (iii) Quantum Field Theory (QFT) is the framework used to describe fundamental particles and forces. Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD) are two distinct (but similar in some ways) models formulated to describe the electromagnetic and strong interactions in nature, and both have been extremely successful when confronted with experiment (QED is the unique model in all of science that produces predictions from first principles in agreement with experiment to an accuracy of nine decimal places).

I also pointed out that Classical Mechanics is already "falsified" since it cannot explain a large class of phenomena -- precisely those phenomena which we refer to today as "quantum" or "relativistic". To explain such phenomena we need to invoke Quantum Mechanics and/or Special Relativity. However, I argued that frameworks should not be thought of as falsified even when they have been contradicted by experiments. Classical Mechanics is still taught as a subject in school and college for a very good reason: it is a very successful framework. We understand that it is successful in the domain where it should be applied, namely the domain where it works! Such reasoning may appear circular but is, quite rightly, accepted and followed in science. It is questionable only if you insist on a literal application of logical positivism and falsifiability.

QFT is a difficult framework and a large fraction of physicists remain unfamiliar with its depths. Perhaps for this reason, it is not widely realised that QFT has also beem falsified, by the experimental fact that gravity exists. QFT with gravity is not "UV complete" and this means it will inevitably break down at very high energies. A number of physicists believe we should not worry about this until we are able to perform measurements at those energies. And we may have remained in this mode but for a fortuitous accident. A model (not framework) had been proposed by Nambu, Susskind and Nielsen to qualitatively describe the binding of quarks in a proton, which has a strange property: the force between quarks is stronger at large distances and weaker at short distances. One (perhaps the only) place where we encounter this in classical physics is the behaviour of a rubber band. So the above scientists (one of whom now has a Nobel prize, though not for this idea) proposed that quarks behave as if they are connected by rubber bands. The formalism to describe this is string theory. Thus, much as in the case of QED, a model led to the development of a framework.

As has happened many times before in physics, string theory began to emerge as a framework that could encompass far more than was originally imagined. From its initial role as a model for quark interactions it grew to provide a consistent framework of quantum gravity, satisfying the very criterion ("UV completeness") that the framework of QFT failed to satisfy. The framework is able to naturally accommodate other "gauge forces" and a bold proposal was made in 1984 that one may be able to find a "theory of everything", a unified model of all fundamental forces including gravity, within the string framework. This proposal may be right or wrong, we don't have much guidance today - neither from experiment nor from theory. There is no compelling model (though models with specific compelling features exist) and no positive experimental result (such as proton decay). And indeed, work on this proposal has been scaled down considerably since the early days.

Through the above developments, a framework emerged which reduces to ordinary QFT in the limit of small strings (exactly as quantum mechanics reduces to classical mechanics in the limit of small quantum effects). It is a very powerful framework that addresses a wide variety of topics in theoretical physics. Indeed, a string theorist today is not someone who necessarily does string theory, but someone who has expertise with the framework and is able to use it wherever needed. In the last ten days alone, I have attended talks on topics ranging from quantum phase transitions in superconductors, to black hole physics, to fluid dynamics, to quantum entanglement, to cosmological inflation. But during all this time I was only at "string theory" conferences, and the speakers were all "string theorists". Many of the talks made no mention of string theory but the theoretical techniques were, sometimes very dimly, related to string theory. The goals in these conferences were not connected to the unification of fundamental forces - a goal that will be revived if and when there is a strong new motivation either from theory or experiment - but rather, to a wide variety of physics goals. The topics listed above are firmly rooted in empirical reality, but theoretical work (without string inspiration) has often been too limited in its ability to provide an understanding of them.

Skepticism is integral to science. But skepticism does not mean that one points to, say, the special theory of relativity and says "I don't like it" (as many people did in the time of Einstein). You may not like it, but you need to present something as good or better and defend that scientifically. In the medium to long term, frameworks or models that are not compelling and serve no useful purpose simply fade out. They do not get stamped out by someone writing an article in Nature whose title is a call to arms and which casually tries to push an unpopular competing theory due to one of the authors.

I'll conclude by providing three possible developments which could easily be around the corner and which would force even skeptics to sit up: (i) the discovery of supersymmetry - this would be an entirely new corner of physics that arises most naturally from string theory, (ii) the discovery of a controlled model of quark confinement within string theory, (iii) the discovery of a tensor-scalar ratio r greater than, say, 0.01 in the cosmic microwave background. If you are interested in physics but don't know about one or more of these topics I suggest you read about them, because they are important.

And if you are a physicist, the question you should be asking is: can I learn something from string theory about the scientific goals important to me?

Thoughts on the scientific method (III): quantum fields and particles

Note: The first two parts of this multi-part article can be found here and here.

Several theoretical frameworks have played an important role in physics. Classical mechanics, quantum mechanics and statistical mechanics are all frameworks. It is worth repeating here that in and of themselves, none of these make direct predictions that can be "tested" or "falsified". For example in classical mechanics one can write down the Hamiltonian of a hypothetical system and study the solutions of this problem, even if such a system has no existence in nature. We do this all the time: problem sets in textbooks are aimed to teach us how to use classical mechanics and not always how to make definite experimental predictions.

It is then up to us to make a model of a chosen physical system and try to experimentally test that model. If the model has been designed with suitable hindsight, it will surely work qualitatively up to a point. But now we test it by going to higher accuracy or varying the experimental parameters. What if the model fails, i.e. it disagrees with experiment? Then there are two very different possibilities: (i) the model failed because it was inadequate as a model and can be improved by tweaking it, for example by adding another term to the Hamiltonian,  (ii) the model failed because classical mechanics as a framework is inadequate to address the problem. Both these types of failures are well-known and well-understood. In category (i) falls virtually any concrete model, for example a model of fluid dynamics that is missing some important feature of the fluid under study. One then rectifies the model by adding a term that captures this feature. In category (ii) is the fact that the electron in a hydrogen atom simply cannot be described by any known Hamiltonian in classical mechanics. One might say the framework of classical mechanics is thereby falsified and replaced by quantum mechanics. But I prefer to think that frameworks are not falsified. They simply outlive their usefulness and applicability.

The appropriate framework to describe elementary particles and fundamental forces is quantum field theory (QFT). It encapsulates both classical and quantum mechanics and extends them to the relativistic domain. By considering finite-temperature field theory, one also encapsulates statistical mechanics. This framework was originally formulated by Feynman, Schwinger and Tomonaga to study the quantum theory of electromagnetism. QFT is difficult and takes years of study to master. But merely mastering how QFT works would not provide us any description of electromagnetism: one needs an actual model within the framework of QFT. This model, called "quantum electrodynamics" (QED) was proposed by the above authors and has been a spectacular success. It is noteworthy that historically, the study of QFT (the framework) and QED (the model) went hand in hand.

Interestingly, QFT also has applications to condensed matter physics. It can be reformulated to describe a many-body system such as a crystal with local interactions between different sites. The framework is (essentially) the same but the physical models one studies are quite different, bearing little resemblance to QED. The models are tailored to study some material of interest, rather than the interactions of electrons and photons in the vacuum. It is remarkable, but no longer surprising to any experienced physicist, that a framework created to deal with one class of systems can be usefully applied to very different classes of systems. In the previous posting I referred to the "renormalisation group" which was also an example of such a framework, indeed it is a part of the overarching framework of QFT.

The fact that one framework can apply to very different systems has played a central role in the development of physics. Perhaps the best example is that of the mass problem for weak vector bosons. Such bosons were proposed by Schwinger in the late 1950's as mediators of the weak interactions. By the early 1960's, many physicists were looking for a mechanism to assign a mass to such particles without contradicting the requirement of gauge invariance, a crucial consistency condition for vector bosons in QFT. A possible mechanism was first suggested in 1963 by Phil Anderson using an analogy with the properties of superconducting materials. These embryonic ideas were converted in 1964 by Englert and Brout, and Higgs, into a mechanism that can be generically applied to elementary particles: the Higgs mechanism.

As I've already mentioned, there was at first no definite prediction of how the Higgs mechanism should be tested, and no definite model - just a mechanism within a framework. But by the end of the 1970's, using both the Higgs mechanism and a novel framework due to Yang and Mills dating back to 1954, a single unified model of the electromagnetic and weak interactions was achieved. It is often called the "electroweak" model because it unifies electromagnetism and weak interactions in much the same way as special relativity unified electricity and magnetism at the beginning of the 20th century. The electroweak model had many predictions, some of which (the existence of W and Z bosons) were soon tested, at first indirectly and then directly. Other predictions like the Higgs boson had to wait 50 years.

In the meanwhile a model of the strong interactions (QCD) was proposed in 1973. The authors of this theory were very clever, but they also had a lot of good fortune. The frameworks of QFT, including Yang-Mills theory and the renormalisation group, were available. Experiments indicated the existence of quarks that interacted weakly at short distances. They proposed QCD by putting together all these ingredients in a brilliant and elegant fashion. I must mention here that if the Yang-Mills framework had not been (i) known, (ii) rendered respectable by its success in a totally different system, the weak interactions, (iii) rendered consistent by the mathematical work of 'tHooft and Veltman, the strong interactions would have remained a mystery. But none of these points (i), (ii) and (iii) have anything to do with experiments on strongly interacting particles.

QCD together with the electroweak theory forms what is today called the Standard Model of fundamental interactions. This describes all elementary particles in nature and all the fundamental interactions among them, except gravity, and it is a stunning success at extremely high levels of precision. Such an ambitious enterprise was surely not anticipated by Feynman et al when they initially formulated QFT. However, if they had been different people, or the age had been different, they might have ambitiously declaimed in 1948 that the QFT framework would come to describe all the fundamental forces relevant for terrestrial particle physics - a "theory of everything". For saying this they would have surely been ridiculed, but they would have been correct.

(to be concluded)

Thoughts about the scientific method (II): goals, models and frameworks

Note: This is part (II). Part (I) can be found here.

One of the most confusing words in philosophical discussions of science is the word "theory". The general public usually does not know what this means, and even within the physics community there is no widespread agreement on its meaning. Compare the following phrases: quantum theory, density functional theory, Fermi liquid theory, BCS theory, big bang theory, theory of elasticity, gauge theory, quantum field theory. Any physicist would agree that the word "theory" is being used here with very different meanings. This makes the question of whether a given "theory" should be testable, or falsifiable, extremely muddy.

I will try my best to shine a little light into the mud (though I cannot guarantee the transmission or reflection of such light!). Let's consider three words that are related to "theory" but have more unambiguous meanings: goal, model, framework.

A goal, clearly, is something that one would like to understand. Some possible goals in Physics are "superconductivity", "nanomechanics", "molecular motors", "quark-gluon plasma", "photonics", and "quantum gravity". These are sometimes phrased as theories, e.g. "theory of superconductivity" but as this example shows, such phrases are very unclear and it's better to think of them as goals. One advantage of focusing on goals is that each one typically has an experimental and a theoretical side: for example an experimentalist may study quark-gluon plasma at an accelerator while a theorist could formulate a model to describe the transport properties of this curious state of matter. However, very often there is no symmetry between the experimental and theoretical sides. For example, photonics is largely an experimental effort to transmit, modulate, amplify and detect light. The theoretical basis for light-matter interactions, known as quantum electrodynamics, is very well known and verified, and one does not aim to test or improve it using photonics (but there is still room for theorists to work out the properties of light in specific media). The important point is that photonics is driven by its potential application in telecommunications, medicine, metrology and aviation, to name a few areas. As such, it is more experiment-driven than theory-driven.

Now let's move on to models. Some useful examples are the "nuclear shell model", "Hubbard model", "Yukawa model" and "dual resonance model". Each of these models is a specific attempt to understand particular physical phenomena. Respectively, the above models try to understand: the energy spectra of nuclei, the metal-insulator transition, the nature of strong interactions, and resonances in high energy scattering. In each case the model is rather precisely aimed at a goal and is somewhat successful in describing the system in question. Also, in each of these cases the model has obvious limitations: the shell model fails to explain multipole moments of nuclei, while the Yukawa model does not provide accurate numbers for scattering amplitudes. In fact, all the above models are "wrong", in the sense that they are all contradicted by definite experimental measurements. In some cases they have been superseded by better models that also do not work completely. For example the shell model was replaced by the collective model that won a Nobel prize in 1975 for Bohr, Mottelson and Rainwater, but it too has had limited success. Inspite of this, the models I've listed are all useful and continue to be used by scientists for various purposes. It is important to understand that though they were contradicted by specific experiments, the models were not thrown out.

I expect a layperson will be  surprised to learn that physicists use models that actually disagree with some experiments. On the other hand, physicists are aware that scientific models can have limited applicability. Though we routinely accept this, I sometimes wonder how honest we are being. It's not that we always decide in advance which model needs to apply to a given situation, rather we often test a theoretical model against experiment, find that it doesn't work, and then - instead of saying "oh this model is wrong" - we say it is not applicable to that experimental situation for some reason. In other words, the model works only when it works. This is not a perfect way to do things, but it's what we can do, and we are all used to doing it.

Finally some words about frameworks. These are less familiar to the general public than goals and models, because they are usually technical, even though they can embody profound physical concepts. A framework is not a model of a system, but a way of thinking about large classes of systems. A very beautiful example, familiar to physicists across many (but not all) areas, is the renormalisation group. This teaches us how to follow the evolution of any microscopic system over a change in the effective length scale. It introduces the notion of "fixed point", a universal behaviour to which a wide class of systems converges. This work originated in particle physics in 1954 and was developed by Kadanoff and then Ken Wilson (who got the 1982 Nobel prize) in the 1960's and 70's in the context of statistical systems. Wikipedia tells us:

 "The renormalization group was initially devised in particle physics, but nowadays its applications extend to solid-state physics, fluid mechanics, cosmology and even nanotechnology.

There is a profound lesson here. A framework like the renormalisation group, on its own, does not make any predictions about any system. It doesn't even know what system we are talking about! In order to be converted into a testable idea it has to be incorporated into a model. When it was proposed in 1954, quarks had never been thought of and quantum chromodynamics  did not exist. However, when experimental circumstances prompted the possibility of a theory of quarks, the notion of renormalisation group was already around and could quickly be incorporated into the seminal work that won Gross, Politzer and Wilczek a Nobel prize in 2004.

Thus a framework is a theoretical concept built out of past experience in physical reality, that takes the theoretical understanding to a higher level and can then be applied in various contexts to situations that may not even have been anticipated during the original development. For example the 1954 work on the renormalisation group was developed for, and applied to, quantum electrodynamics, but had this enterprise failed to be tested, the framework would still have been lying around waiting for its applications to yield the 1982 and 2004 Nobel prizes. From the standpoint of theory, frameworks are incredibly valuable things, often more valuable and durable than models.

(to be continued)

Thoughts about the scientific method (I)

After a long time away from this blog, I felt compelled to return to it. The proximate reason is a recent article in Nature about what does - and does not - constitute science. But I'll first introduce the topic and make some comments on it, then get to the article in a subsequent posting.

The issue at hand is "what is the scientific method?" and "what constitutes science?" (as opposed to pseudo-science or non-science). This keeps popping up for a variety of reasons. On one side, there are schools of thought that would like astrology to be included with science. This worries many (not all) scientists. On the other, there is a concern that some branches of science as currently practiced are "not scientific". This also worries some (not all) scientists. In both cases, the empirical method and the concepts of testability and falsifiability are produced to justify the arguments made. My concern is that there is not enough reflection on what this method and these words really mean, and I would like to put forward some thoughts on this.

Let me start by quoting from a popular article I wrote for the Times of India  about seven years ago:

The notion that scientific theories must be tested experimentally is fundamental to the doctrine of positivism, which also requires that theories must always deal with quantities that are observable. [...] But Steven Weinberg, a Nobel Laureate and one of the greatest living physicists, asserts that "positivism has done as much harm as good". To make this point, which he develops at length in his excellent book "Dreams of a Final Theory", he argues that it was positivism that kept a number of scientists from believing in atoms, in electrons and much later in quarks.

Weinberg supports his claim with a comparison of two scientists. The British physicist J.J. Thomson is credited with the discovery of the electron, but Walter Kaufman in Germany performed the same experiment independently at the same time, and even managed a more precise measurement of the electron's properties. While Thomson reported the discovery of a new particle, which he named the electron, Kaufman merely reported the phenomenon he had observed (the bending of cathode rays). Exercising a positivist's restraint, he did not assume it corresponded to a new particle. [...] The harm caused by a positivist approach, in Weinberg's view, is this: unless one is willing to make - and believe - a hypothesis based on the limited information available, there tends to be a lack of direction in one's subsequent research. Only if one makes a conjecture about what is happening, defying positivism at least temporarily, is one motivated to perform experiments that can confirm or deny the conjecture.

The physicists I know routinely claim to be positivists. However, when confronted with the above argument, which contradicts their point of view, they instantly agree with it. I don't mean to only criticise others: I'm an early example of this phenomenon. In 1998 I attended a workshop in Santa Barbara where Stephen Hawking gave an informal talk to a round table of around a dozen people. He started by saying he was a logical positivist and then added "this is also how most physicists would describe themselves, if only they knew what it means". I was in awe of Hawking and was seeing him for the first time. So it never crossed my mind that he could be talking through his hat, but now I'm pretty sure this was the case.

This is not to say that I disrespect the spirit of positivism. Experiment and experimental verification are fundamental parts of science. The problem arises, just as in the example above, when one forgets some key factors: (i) the complexity of the interplay between theory and experiment, (ii) the presence of (sometimes long) periods where one or the other of these has to surge forward without any support from the other, (iii) the role of intuition, guesswork and leaps of faith in temporarily furthering the cause of science.

To explain point (i): there is no simple mechanical routine where someone does an experiment, then someone writes a theory to explain it and predicts a new experiment, then another experiment is done etc. The interplay is complicated and often incomprehensible to both theorists and experimentalists at the time they are working. This is why every great scientist confesses in her retirement speech that she didn't really understand what was going on while she was making great discoveries.

On point (ii), there are periods in science when theory is stuck for lack of ideas or computational tools, or experiment is stuck for lack of ideas or experimental equipment. At present there is little theoretical understanding of "dark matter" but experiment must continue until the theorists catch up. Conversely there is little experimental understanding of "quantum gravity", so theorists must do their work and wait until experimental understanding is achieved.

Finally about point (iii), the word "temporarily" is crucial. A fundamentalist who blindly follows positivist ideology might not be able to do what everyone in science routinely does: mull over a hypothesis at night and resolve to test it the next morning. Just 12 hours of speculation might, in his overly pedantic view, be considered non-positivist! Of course, no scientist would consider such speculation wrong or unscientific. But if it's OK to speculate overnight, is it OK to do so over a month, a year or a decade? And this is a very crucial point. The scientists who designed and built the Large Hadron Collider relied on theoretical speculations from 1964 about the existence of a Higgs boson (this is why the experiment was optimised to find this boson, and found it nearly half a century later). Do we consider fifty years of speculation about the Higgs to be unscientific? I think not.

I know the standard response to this line of argument: "The Higgs speculation was focused on creating an experimental test. If the Higgs were eventually found it would validate the speculation, while if it were not then the speculation would have been falsified. Thus the entire process followed Karl Popper's criterion of "falsifiability" and is therefore admissible as science."

I disagree on two counts. The Higgs hypothesis was not initially focused on an experimental test. Englert-Brout and Higgs did not suggest any experimentally verifiable picture of their idea in 1964. It took many years of theoretical research to arrive at the possibilities and predictions that were lined up by the time the LHC started to operate. So the fifty years until verification were not merely due to experimental limitations. There were theoretical issues that needed to be understood, in a speculative (i.e no Higgs particle was known to exist) but totally scientific context.

My second disagreement though is more significant. I simply don't agree with Popper's falsifiability criterion. It sounds nice the first time you hear it. However - like all the lapsed positivists described above - you may change your mind when you consider its implications.

Continued.... Click here for the next part.

The great Indian rock opera

Not content with outsized newpaper headlines and celebrations in the streets, the Indian public apparently now wants to know what's going to happen next! Patience was never our virtue, was it!!

I can tell you with complete confidence that I don't know what's going to happen next, and nor do you. We have a new government and its job is to govern. Some opinionated individuals are completely certain that it's going to be a huge success, others are equally certain it's going to be a gigantic failure. Again, I can tell you with complete confidence (where do I get all that stuff from?) that it's going to be somewhere in between.

India is very much a nation of conflicting demands. For many decisions the government has to make, there will be some group that benefits and is pleased, and another that loses out, and is unhappy. There is, however, one kind of person who's in for a severe disappointment. From the tone of some of the blogs/emails/tweets going around these days, a number of people believe our new PM is going to solve their personal problems ("Dear Modi-ji, my neighbours are renovating their flat and the drilling noise keeps me awake on Sunday afternoons, so could you please...."). These people are not likely to get their wish. For obvious reasons the following lines from a wonderful rock opera, Jesus Christ Superstar, have been rattling around in my head:

Christ you know I love you
Did you see I waved?
I believe in you and God
So tell me that I'm saved

Jesus, I am with you
Touch me, touch me Jesus
Jesus, I am on your side
Kiss me, kiss me Jesus

It may not please Mr M to be so closely identified with a leading figure of a different religion, but the feeling is certainly in the air. And the analogy actually gets more interesting. The above song continues with the apostle Simon the Zealot persuading Jesus to incite the masses against the Romans:

What more do you need to convince you
That you have made it and you're easily as strong
As the filth from Rome who raped our country
And who've terrorized our people for so long?

There are all too many candidates for the role of Simon in today's India! My own favourite choice would naturally be journalist Tavleen Singh. How surprising that she didn't dig up these lyrics when there was still time to fling them at the family she hates so much - especially given some uncanny resonances...

What seems most unlikely though, is that Mr M will respond the way Jesus (in the rock opera) did to Simon:

Neither you Simon, nor the fifty thousand
Nor the Romans, nor the Jews
Nor Judas, nor the twelve
Nor the priests, nor the scribes
Nor doomed Jerusalem itself
Understand what power is
Understand what glory is
Understand at all

No, if there's a person of Jesus-like modesty in our government then he is presently vacating an office, not moving into one.

Right-turn coming up

I must start by complimenting myself on my admirable restraint - having not written a single blog post during the run-up to the elections. So whichever way my country goes next, it cannot possibly be my fault! Moreover I've cleverly chosen what might be the most uninteresting moment in which to blog: after voting is complete, but just before the results are declared.

More seriously, though, the world is seeing a significant shift towards the right-wing and it's no surprise that this is also happening in India. As an example, the UK Independence Party is poised to win the European Parliament election in the UK a week from today. UKIP is described on Wikipedia as a "Eurosceptic, right-wing populist" party and it is particularly opposed to immigration to the UK by Poles, Romanians and Bulgarians. Right-wing politicians like Geert Wilders and his Party for Freedom (PVV) are doing well in Europe. In India it's reasonable to expect that the BJP is going to perform well in the present elections as the exit polls predict, though the details are far from clear.

The right-wing outlook is, broadly speaking, hostile to "outsiders" (however they may be defined), positive about the role of majority religion, and friendly to business. In very rough terms I suppose both supporters and opponents of the BJP would agree with the above description of its philosophy, though they might list the three attributes in different orders. Similar descriptions can be applied to UKIP, PVV and other European parties like the Front National (France), Lega Nord (Italy), the Danish People's Party, and Golden Dawn (Greece). And yet, for many reasons these parties don't generally see eye to eye with each other. Partly this is because one person's fellow-citizen is another's dreaded immigrant: right-wing Greeks don't want Pakistanis at their borders, but right-wing Britishers don't want Greeks at their borders. And this is only a small part of the enormous differences of outlook. Politics is a complex thing and it is rare for any group to fit a mould. For example Marine Le Pen's Front National is not particularly friendly to business. Golden Dawn is fascist to an extent that would cause other right-wing parties to cringe. Geert Wilders is pro-gay but denies climate change, while the BJP - I imagine - would have precisely the opposite view on these two issues.

It is worth trying to understand the right-wing point of view better, especially if one does not share it. As Spinoza nicely put it: “I have striven not to laugh at human actions, not to weep at them, nor to hate them, but to understand them”. But a more particular reason, specially in India and specially today, is that this outlook is gaining dominance and one has to live and work with it in the foreseeable future (and perhaps also struggle against some aspects of it). So it's best to be mentally prepared.

I expect this will be a long discussion and it would be pointless to put down all my thoughts in one go. So I'll just make a single important point. Voting in an election involves serious levels of compromise. It's not possible to have a candidate made-to-order, and still less a party that you completely agree with. So, what exactly do you do if - say - you favour big business but would like religion kept out of the public sphere? On the other hand, what if you oppose the majority religion but are even more opposed to minority religions?  Or, if corruption is a huge issue for you but so is governance, and you worry that a small newly-arrived party simply lacks the experience to provide the latter? In all these cases, you may end up voting for a party despite feeling discomfort about some of its stated policies. And I think that's likely to have happened on a large scale in this election. This is important because what the future government does is still subject to checks and balances (through the opposition, the courts, the press etc). Through these agencies citizens must assert the specific values for which they voted, rather than quietly accept the full package we will be getting.

(Disclosure: I personally voted for the excellent Mr Subhash Ware despite some discomfort about his party, on which I blogged here. Regardless of what I said at the time, I believe AAP has an important role to play in Indian politics and hope it gets the chance to do so.)

Academia and the equations of power

When I joined academia there was something I considered obvious: that at least in an academic environment, questions of fairness would be settled by taking the facts (and only the facts) into consideration. After all this is supposed to be how we do science. If a scientist argued that his papers were correct and those of his rivals wrong just because he was a Head of Department and the rival was merely a postdoctoral fellow, we would all have a good laugh. At least in any institution of a decent standing.

My illusions were challenged during my term as a postdoctoral fellow. A senior faculty member (call him F1) in my department tried to convince me of his new theory about a very old question of basic physics: if you cover a glass full of water with a card and turn it upside down, why does the card not fall? His theory, which didn't sound right to me (because it wasn't), even had an experimental prediction: he claimed that the card only stays in place if the glass is cylindrical or has a narrower base and wider top. If the glass has a wide base and narrow top, he claimed, the card would fall. Then with an impish grin he said "let me put you up to date with the experimental situation. A colleague (faculty member F2) has done the experiment at home and it confirms my theory". I tried to explain my approach and why I disagreed, but could not exactly put my finger on the error in F1's explanation because he was doing things a different way (i.e. trying to balance forces instead of pressures) which I found more complicated and less intuitive. I should mention here that F1 was an academically honest person and his attitude during the debate with me was respectful and courteous throughout.

Just then, F2 walked in along with a very senior colleague, F3. F1 looked at them and said "Sunil here disagrees with us". Their attitude was quite different from that of F1. With a visible sneer, one of them said, as if I wasn't even there: "Oh, he disagrees?" and the other looked at me patronisingly and said "ha ha, you're wrong, I've already done the experiment". They then proceeded to try and intimidate me with all kinds of irrelevant questions. I was the only one in the room without a permanent job and F2 and F3 were using this fact, rather than science, to win the argument. But then a funny thing happened. F1, who had been staring at the blackboard, had an illumination. He suddenly started making changes to his original diagram to incorporate some force arrows he had left out, and concluded that I was right! This left F2 and F3 in a rather embarrasing position and they left the room with ill grace. For what it's worth, I repeated the experiment later on at home and got the obvious result (the effect doesn't depend on the shape of the glass).

Years later, by which time I was a senior faculty member, an issue came up involving the unfair negative grading of a junior administrative staff member by his immediate superior, resulting in a memo being issued. A meeting was called involving the Director, Deans and a few senior faculty wherein I explained the facts and argued that the negative grading should be reversed and the memo withdrawn. No one disputed the facts I had presented, but apparently they all found it less clear what to do. The Registrar, a person who managed to be obtuse about everything except power equations, had the cheek to say "it will send the wrong signal, that any administrative staff member can get a memo against him cancelled if he is friends with Sunil Mukhi". I spluttered but was asked by my faculty colleagues to be patient. Then, without actually saying so, they quietly did the calculation: in terms of power and authority I was outdone by the others in the room, both in numbers and seniority. So there was no need to change anything. However as I was angry and showing signs of getting more so, and also happened to be correct (none of these distinguished scientists expressed any disagreement about the facts of the case) it was decided to withdraw the memo on a pure technicality. To my knowledge it still sits in the file of this person, marked "cancelled" for a technical reason, but still full of venom about a completely innocent person penned by his incompetent superior out of spite. He never got any letter saying the memo stood withdrawn (had he asked for one, he would have got another memo for being cheeky). The spiteful superior was never disciplined.

Readers of this blog, if any, will argue that none of these cases is surprising in the Indian context. They are, if anything, rather mild (the postdoc got a faculty job, the memo got cancelled). Which is why I decided to put down the above reminiscences only today after reading a fascinating new story, published in Science. A postdoctoral researcher at Yale called Magdalena Koziol, working in the lab of Antonio Giraldez, had her zebrafish poisoned by a fellow postdoc. Koziol, suspecting sabotage, started leaving two batches of zebrafish in the lab - one labeled with her name and the other unlabeled. Only the batch bearing her name died. Thereafter hidden cameras were installed that caught the culprit, who confessed and obviously was sacked. But Koziol claims that her adviser Giraldez told her not to talk about it to anyone, and declined to give her a letter explaining what had happened, or help her make up for the research time she lost while all this was happening - which can be critical for the career of a postdoctoral scientist. He then turned increasingly hostile to her. Now she has filed a lawsuit against Giraldez and Yale University. You can read more about this case on this blog (or on Science if you have a subscription).

The issue is in court, but there is something more to the case that, in my opinion, will play a major role in deciding the outcome. Koziol has left Yale and returned to the lab of Nobel Laureate John Gurdon where she originally did her Ph.D. He has helped secure a small grant for her to carry on her research, and even contributed some personal money. Perhaps more important, he supports her case against Giraldez and Yale University, and has come out with this remarkable quote:  “They wrote her a letter promising her circumstances in which she could conduct her research, and they quite clearly did not provide even remotely adequate circumstances.”

I don't personally know the full facts of the case, which I'm sure will be put before the court. But I believe I have enough training by now to guess the relevant equations:

1. Giraldez + Yale University + Yale's lawyers  >>  Koziol + Koziol's lawyer
2. Giraldez + Yale University + Yale's lawyers  <  Koziol + Koziol's lawyer + a Nobel Laureate (Gurdon).

So my prediction is they will settle out of court, or else she will win in court. But we can't test what would have happened if there were no Nobel Laureate in the equation.

Mango pickle

Recently I've had a bit of a debate with friends on Facebook about the Aam Aadmi Party and would like to use this space to think out my views and share them.

Arguably the most important new phenomenon in Indian politics, the AAP is a party whose philosophy (or perhaps, lack thereof) has left me in grave doubt and discomfort. This discomfort dates from their earlier incarnation as a protest movement against corruption, but has intensified since they came to power in Delhi.

It has become an axiom that India's leaders wallow in an evil stew of dishonesty, corruption and criminality. This axiomatic view is one of the roots of my discomfort. Axioms do not require justification, they are just taken to be true. As a scientist, I would instead like to investigate rationally and argue step by step. That allows for a little more perspective and also for correcting errors in the argument if any.

Now, even with my best debating skills I can hardly argue that India's elected leaders are particularly admirable. It appears that a significant number of them habitually commit  crimes, both social (such as rape and murder) and economic (such as corruption and theft). The question I want to raise is whether these persons are, in this criminal aspect, worse than the rest of us Indians, or in any specific way different from us. Or are they just the same as the rest of us on average? This is the central question whose answer determines how we should respond to the criminality of the political class.

Naturally politicians cannot be exactly like the "rest of us" due to the crucial difference that they have power (whatever the AAP might say, politics is power). So the question above has to be rephrased thus: are India's politicians just the same as the rest of us on average except that they are able to more easily indulge their criminality due to their power?

My answer is a clear "yes". Politicians have no unique claim on murder and rape - these days it seems everyone from mighty judges and magazine editors to humble security guards and bus drivers is involved in the business of sexual molestation. Politicians have no unique claim on corruption either. Their own corruption is usually in conjunction with powerful business interests. But plenty goes on without any help from politicians. Match-fixing is corruption on the part of bookmakers and sportspersons. Corruption and sexual molestation in Bollywood are nothing new. Businesses routinely pay TV and newspapers to propagate their case - a good example where both industry and media are corrupt without any help from politicians. So why do politicians get singled out for blame? How can we expect better from them when our society and culture are no better? How can we reform them before reforming our culture?

Now I can articulate my unease about AAP. Instead of trying to lay bare the root of corruption and exorcise it, it has become a nodal agency for shifting the blame outside ourselves. Its appeal to the urban middle-class voter is to basically pretend that corruption is something "out there", that we are merely its hapless victims and that the government refuses permission for anything only to extract a bribe. This makes AAP - as presently functioning - a part of the problem, not the solution.

To this day, most Indians will cheerfully give a bribe if doing so provides them an edge over someone else (who among you has not bribed for a railway ticket? did you ever think about the poor soul on the waiting list from whom that ticket was wrongfully snatched?). By turning the camera away from ourselves and onto someone else, the AAP has propped up the favourite construct of guilty persons: blaming the "other". From this perspective, the recent raid on Africans in Khirki village was no aberration. Prostitution and drug abuse are widespread in Indian cities and the law must be used to redress this problem. But the raid on the Africans was intended to convey a different message: that prostitution and drug use are not "Indian" habits and have come to us via dark and perverse foreigners. The AAP's website continues to defend the raid, by the way, and a thought-provoking attack on their defence appears in this article. So I'm afraid we can expect more moralising and distancing behaviour from this party.

Gandhi tried to teach us that true reform is reform from within, and he was completely right about that. All that is good about India (and there is a lot) has its roots in our cultural selves. All that is bad (and there is a lot) also has its roots in the self-same culture. Good or bad, we are all implicated. I don't know which political party will dare to tell us this and risk its vote base, but that's what we need to hear in order to make progress.

If you're with us, you're also against us

Scientists such as myself were delighted to learn that the National Security Agency (NSA) of the United States plans to build a quantum computer. The news first appeared in the Washington Post, you can read it here. Previous attempts at snooping on civilians have tended to use physics mainly in the form of electronics, a subject that was exciting many decades ago but is no longer considered to be a part of physics at all. Quantum computing, by contrast, is a major buzzword these days. With the NSA's move in this direction, everyone living outside the US (the "snooped-upon") has a chance to be involved with the deepest questions in science, or at least to be the victim of people engaged in studying these questions.

For the benefit of readers who do not understand how quantum mechanical spying will enrich their lives, let me  imagine a system where it is possible to be in one of two states: "with us" and "against us". The classical dynamics of this two-state system was famously analysed by one George W. Bush, who correctly observed that it was possible to be in only one of these states. But in quantum mechanics things are different: one can be in a quantum superposition of the two. A simple example would be a person who is "with us" with an amplitude of one over the square root of 2, and also "against us" with the same amplitude. Importantly, the phase of "against us" can be arbitrary relative to "with us", leading to the possibility of "quantum interference".

Imagine a person in the quantum state just described. As long as the NSA does not spy on her, she will simply remain in that state (for which reason it's called a "stationary state"). But suppose they measure whether she is "with us", as the NSA will surely want to do. This leads to a disastrous phenomenon called "collapse of the wave function". The poor soul will instantly find herself to be either "with us", or "against us", and the probability of collapsing into each of these states will be exactly a half. Moreover, and I can hardly stress this enough, all subsequent measurements will return the same state as the first one. We physicists like to say that the person went into an eigenstate.

It is not clear, at the time of writing, whether collapsing a person's wave function and forcing them into an eigenstate is as serious a violation of human rights as collapsing their humanity and forcing them into Guantanamo prison. As usual, the NSA is way ahead of the United Nations on this matter. Even physicians can't be certain: is forcing you into an eigenstate as painful as forcing water up your nose? Today this is a known unknown, but once the NSA unveils its powerful quantum computer we will be sure. Or perhaps we will only know with a definite probability?

As a human-rights supporter, I look forward with interest to the first quantum trial in a court of law. The dialogue might run like this:

Judge: Is the defendant with us or against us?
NSA: Yes, your honour.
Judge: You mean she is the sum of both?
NSA: Not necessarily, your honour. She could be the difference of both. Or a complex combination.
Judge: You mean you couldn't detect the phase?
NSA (looks at shoes): No, your honour. Our quantum computer programmer isn't good with complex numbers.
Judge: Case dismissed!