Tuesday, 12 December 2006
Quantum Sock Theory
The advent of mechanised means of cleaning clothes brought new challenges and exposed new phenomena unexplainable by the old manual theory of laundry. In particular, the discovery of spontaneous sock disappearance was totally contrary to the principles of pair production. A new theory of laundry was required, one that took into account quantisation of the textilo-clothic field, whose quantised carriers are called lint. Not only did the new theory correctly predict the spectral distribution of coloured lint on a black garment, but also the phenomenon of tunneling, the disappearance of socks from a nominally closed laundry system being one of the more startling consequences.
Socks obey Hoson article statistics which apply to indistiguishable articles of clothing such as a pair of socks. Socks do not like to be in the same state, even the same country, let alone the same washing machine. When brought into violent collision within the agitation cycle, and the spin cycle in particular, the inter-sock potential can reach such high levels leading to an interdimensional tear in the fabric of spacetime. How this actually occurs is still uncertain, requiring a deeper theory which can take into account the discontinuous nature of fabric at the Pluck length. The leading, or most vocal, candidate for such an ultimate explanation is called Thread Theory.
Sock Chromo Dynamics (SCD) is a development of the basic theory to take into account another property of socks, which Sockocists whimsically have called colour. However, it seems that, unlike spin or charge, colour is not a conserved quantity, especially in the presence of bleach. It has also been posited that a phenomenon call mixing can also occur. Observed is also the related phenomena of Fashion Violations, such as the wearing of different coloured socks, but this is usually only observed in Universities, especially Maths, Engineering and Physics departments.
Sockocists are eagerly waiting for the completion of the LHC (Large Hosiery Collider) which will be able to explore the collision of heavier or larger articles, such as stockings, pantyhose and tights. Vigorous tumbling of these larger articles may lead to insights into the elegant, but yet unproven, Twisted Theory and even the more abstract Knotted Theory.
Thursday, 5 October 2006
The talk by Collins briefly recapped his research into "Interactional Expertise", but the main body of his talk was devoted to the notion that you can be a physicist without maths. He goes so far as to advocating specific physics courses with no mathematics, to train physics-savvy grads for managerial roles in society. Now, if one looks at the spectrum of mathematical ability within the physics community, it varies by quite alot, from mathematical geniuses, like Witten, to the less adept (but perfectly satisfactory physicists) usually to be found in the laboratory:-). Just because not all physicists are at the former end of the spectrum (and I would count myself firmly in the middle of the pack, or even below due to atrophy), it would be wrong to conclude that simply the existence of mathematically less capable physicists means that it is desirable to try to teach physics without maths. Usually, great physicists (Collins presents Bohr and Drever as examples, which may be arguable) who aren't great mathematically succeed despite their mathematical failing, usually compensated by a formidable intuitive grasp of the physics. However, these people lie way outside the norm (for physicists) and they are the exception which proves the rule. One may argue that traditional physics courses are predicated on the assumption that students be mathematical, so it is not surprsing that physicists have in general greater mathematical ability than the general populace, hence the mere fact that physicists have mathematical ability (to greater of lesser degree) does not in itself show that you need maths to be a physicist. But I'd argue that what separates physics as a science from merely a collection of facts about the universe is that mathematical models give concrete form to theory, and without being able to grasp the language in which the models are described, one cannot really be called a physicist. Besides which, trying to teach physics without maths is a like doing a marathon walking on your hands, in principle doable, but ultimately fruitless.
The other talk was a different kettle of fish. I wasn't quite sure exactly what Reid was tring to say. Most charatibly, he is imploring a more humane, kind and individually tailored approach to patient care, or basically better bedside manner. I have no objections to this sentiment. Less charitably, he could thought to argue that a doctor should be concerned mostly with making a patient "feel" well, rather than concentrate on the notion of "disease". There certainly is some scientific evidence that psychological factors are important in physiological response to illness and treatment. However, one should balance the relative magnitude of this effect with respect to other physical factors. There are philosophical questions raised by this approach. We should bound ourselves in nutshells and count ourselves kings of infinite space. If we perceived ourselves as well or bettter, then the actual reality is not important.
Reid was quick to duck any questions on Homeopathy, preferring to concentrate his talk on his vision of Integrative Healthcare, where doctors are melded with the role of welfare officers and crisis talklines. Sprinkled throughout were potshots (via cartoons) at NHS managers and drug companies, easy targets especially since the majority of the audience seemed to be quite sympathetic.
I think underlying the current rise in Complementary and Alternative Medicine (CAM) is the unrealistic expectations people have about medicine, a victim of its own success one may say. "Shit Happens" and when fate deals out a losing hand, people feel cheated by conventional medicine and seek alternative treatments to fill their hopes.
There are parallels between the fight against quack medicine and pseudo-science. Both stem from a mis-understanding of what science actually is and what its limits are. People prefer certainty, but if Science and Modern Medicine cannot provide that, they will seek out other forms of assurance. That's not to say that modern conventional medicine doesn't have its own failings, but the inability to "cure" the incurable isn't one of them, just like the inability of science to provide "truth". I cannot see a quick fix to this problem, apart from making everyone pass a basic course in philosophy (of science) and critical thinking.
Saturday, 23 September 2006
One may try to use the results of the sociology experiment (Is this ironic, to use the techniques and methodology of the subject under study?) to reinforce the claim that all of science is simply social construction, that scientific truths have no greater claim to validity that any other socially conventions, and other notions of linguistic hegomonies. However, we need to look at the actual study and how it fits in with the wider framework of their sociological research. They distinguish between different grades of expertise and in particular, the sociologists do not claim to have imitated "contributory expertise", the ability to do research, merely the ability to appear to speak as if one had the ability.
I myself am philosophically in the functionalist camp. If someone does all of the things that a gravitational wave physicist does, then functionally they are a gravitational wave physicist. A full Turing test would probe the full technical competence of the subject. As it stood, the questions asked in the test were conceptual rather than technical or claculational so did not probe all of the functional aspects of being a gravity wave physicist. A movie set of submarine may look like a sub but can't submerge. I am reminded of the great mathematician, Ramanujan, who exemplified the total opposite of interactional expertise. He was totally self-taught, not even having talked to another professional mathematician before he was brought to Cambridge by Hardy, yet even today his results are still filtering into mainstream mathematics.
You can't spend 30 years with gravity wave physicists and not pick up some of the physics. The important part of the responses were that they were technically correct. Even though the sociologist couldn't do calculations in linearized general relativity, he had absorbed enough physics to answer the questions correctly. This is what happens when you go slightly out of your speciality, you may not be able to be perfectly conversant with the theoretical techniques but may know enough to understand the general concepts involved. But a thorough scientific training should allow one to bootstrap what one already knows to learn the new field. I greatly admire S. Chandresekhar who changed his specialism six times in his career, writing monographs on each field at the conclusion of each episode.
So what? Science, contrary to what some radical cultural relativists would say, is not about making up stories about the world and merely talking in the right terminology and giving the expected answers demanded by a imperialistic and fascist orthodoxy, but is about doing, probing nature and contributing to a tightly constrained framework of observation, experiment and theory.
Monday, 28 August 2006
A String Theorist, with whom I spoke about the book, was quick to affirm that he himself did not think strings were going to be the fundamental theory, but rather the techniques developed by string theory has actually be useful for conventional QCD. So even if the strong claims, by a minority of String Theorists it was stressed, were mostly hype, he reiterated the argument, "It's the only game in town". Whether this is a compelling argument is not clear to me but Lee Smolin, who has worked in String Theory, would disagree, citing several different approaches to unification in his book which also is critical of the present domination of the String Theory.
I think it's an exciting time to be a physicist despite the apparent stagnation of fundamental particle physics. We are only beginning to plumb the depths of complexity of many-body physics. Quantum computation and information is an example of where whole avenues of phenomena were waiting to be discovered, despite all the work on quantum theory and the foundation of its mathematical principles. Though it's not inventing "new" physics, we are discovering surprising things about the connections between established sub-fields of science. Looking further out, new astronomical observations are raising more questions than they answer, dark matter, the cosmological constant, gamma ray bursts etc. The opportunity to discover important insights is not simply confined to String/M/Brane Theory.
And they are so confident that they have thrown down the gauntlet to the scientific community in a bid to prove that they have rewritten the laws of physics. Last week, frustrated that they couldn't persuade scientists to take their work seriously, McCarthy, Walshe and the other 28 shareholders of Steorn, a privately owned technology research company, took out a full-page advertisement in the Economist. In it, they called upon scientists to form a 12-member jury to decide whether their free-energy system is real, hoaxed, imagined or incorrectly well-intentioned.
The problem is that extraordinary claims require extraordinary evidence, and that the burden of proof in such a case is really on the side of those making such claims. When modern physics, within its long-established borders, has been so successful and consistent, coming up with a perpetual motion machine would seem to be extremely unlikely.
According to McCarthy and Walshe, the marketing manager, there have been no fewer than eight independent validations of their work conducted by electrical engineers and academics "with multiple PhDs" from world-class universities.
The fact that conventional physics is so successful and consistent, any credible evidence that the inventors' claims were true would have any true physicist to drop everything they were working on, and instantly switch to studying such a violation of all known laws of physics. They are claiming up to 4 times as much (mechanical) energy as they are putting in. A signature of free energy this large would be absolutely unmissable. Why haven't we seen anything run? They need only hook up one of their devices via a generator to the electricity grid and start making money.
Of course, the whole affair is running along the usual lines for a fringe claim. Conventionally, if a scientist makes a great discovery, after filing the necessary patents of course, they will disclose the set-up and techniques required to reproduce those results by independent researchers. If others are able to reproduce the results or confirm the observations, then one can have more confidence in the validity of the original claims. However, the inventors of this latest affair are, "seeking a jury of twelve qualified experimental physicists to define the tests required, the test centres to be used, monitor the analysis and then publish the results." This strike me as very odd. Science is not about testing black boxes. Without access to the inside of the black box and an attempt to understand its properties, the whole thing looks especially dubious. Why are their white papers restricted to registered academic users of their web-site and potential jurists? Why not post them on the arXiv like every other working physicist? The papers, here and here, claiming an anti-gravity effect above rotating High Tc superconducting discs were posted there (not that I find these claims credible either).
Even the Pons and Fleischmann affair was conducted slightly more openly. Other researchers tried to reproduce the experimental set-up but failed to obtain convincing data. Even then, the manner in which th original "results" were announced, the supposed signatures of fusion, and the ultimate lack of firm confirmation by anyone else has lead to cold fusion dying away. The supposed mechanism of cold fusion was at the extreme boundary of known physics, ultimately beyond it, but at least it was not totally inconsistent with what we know (just a extremely inconsistent).
It isn't up to the physics community to take up any "challenge", the challenge is for the inventors to back up their claims with proper disclosure for a truly scientific evaluation. Until that is done, the whole business cannot be taken seriously.
Sunday, 23 July 2006
Since I don't get to do any experiments, wear a white (or any other colour) lab coat, or play around with impressive looking apparati, my attempts at depicting the kind of work I and my colleagues do are usually quite unimpressive. All we do everyday is sit around in our offices, in front of a computer or a notebook, occasionally scribbling random greek letters on a big whiteboard, accompanied by a cup of coffee in hand. No machines which go "bing!" The picture on the left is about as much fun as it gets, Stephen Hawking listening to a talk by Roger Penrose about his latest ideas on quantum state reduction via gravitational interactions.
So in a way I understand the urge to spice things up with unrepresentative imagery. Visually, a lot of a scientist's job is as interesting as any other office worker's. No one is really interested in seeing people think. Occasionally, there's a really animated discussion with equations and hands flying all over the place but that's about as exciting as it gets around here.
Still, why should scientists care about having their dull (at best), or menacing (at worst) perception by the world at large spruced up by photographic glitz? For me, it crosses the line between documentary and imaginary. A fundamental goal of science is to present the clearest and accurate picture of nature that we can. Although it is part and parcel of the day-to-day machinations of science that we may emphasize our own particular contributions, and and are every bit as emotionally involved in our work as anyone else, lying about one's work is an anathma. One can make an analogy with journalism, once a reporter starts making stuff up in their articles, they have crossed the line of jounalistic integrity. Scientists have at least as strong a responsibility to present fair, balanced and truthful accounts of their work as possible.
I would posit that this onus extends to the portrayal of the work we do, in whatever medium. Here, the TV show CSI and its spinoffs have a lot to answer for. Stylish offices, flashy computer graphics, DNA tests which take 10 seconds, these are all absolute fictions. Of course it's entertainment, but one of the main attractions of a show like that is it is supposed to make science, and scientists "sexy". However, there is a danger of misrepresenting what science can and cannot achieve, as well as giving a totally misleading account of work conditions.
Still, having to take pictures of my workmates at work (as opposed to at play) is akin to pulling teeth. It's not an easy job but the challenge to do it in an interesting way without resorting to gimmicks is a worthwhile one which I implore other photographers to tackle. Otherwise, it is missing spirit of science and doing it a disservice.
Saturday, 22 July 2006
1. Don't rub in suncream
It turns out we have got it wrong all these years. If you rub suncream into your skin until it vanishes, regardless of what factor it is, you will have reduced its efficacy to zero, and your risk of skin cancer will be undiminished. The correct way to apply it, it transpires, is to slide on a thick buttery layer that remains clearly visible, and leave it there to dry on the surface of your skin. Attractive, eh? Maybe best to cover up or stay out of the sun altogether...
This is an example where journalistic pressures have distorted the actual scientific findings. This bit of reporting comes from a recent report from the The Restoration of Appearance and Function Trust which was also reported by the BBC (who did a better job, but still managed to distort the issue). The scientific paper upon which these findings are reported is,
Haywood R, Warden P, Sanders R, Linge C. Sunscreens inadequately protect against ultraviolet A-induced free radicals in skin: implications for aging and melanoma? J Invest Dermatol 2003;121:862–68. It's three years old so I'm puzzled why only now is this issue being trotted out to the public. Anyway, a closer reading of the paper spells a slightly different picture to the popular accounts.
The findings were that rubbed in sunscreen had minimal protection against UVA induced production of free-radicals. Free radicals are a possible mechanism by which certain types of skin cancers (melanomas) may be induced, though the link is far from clear in humans. The protection against UVB was practically unaffected by rubbing in the sunscreen, it is usually how SPF is determined . UVB has been strongly linked to basal and squamous cell carcinomas, the mechanism is direct DNA damage.
The Guardian report totally misrepresents the reduction in effectiveness of rubbed-in sunscreen, not reducing it to zero as claimed. The BBC report fails to mention that UVB, aside from causing reddening of the skin, is also responsible for skin cancer as well.
Why is this important? I'm not advocating we become blasé about the dangers of sun exposure (I grew up in a country where we're paranoid about skin cancer, not without cause mind you with the highest skin cancer rate in the world, 6 times that of the UK) and it's a risk which can be easily avoided. The issue of science reporting is much greater and extends to the role of the media in presenting science to the public. The public perception of science is greatly skewed by the "spin" journalists and editors place upon science stories. The real issues are not so simple as the media makes them out to be, inviting simplistic responses. The research upon which this latest scare-mongering is based upon seems like perfectly good science, the methods and results are uncontroversial. However, the interpretation and conclusions as translated in the media are unwarranted.
With scientific issues such as anthropogenic climate change, radiological safety, pollution, biodiversity and asteroidal impact threats of great importance, media driven agenda are not beneficial, especially when the scientific bases upon which we need to decide what actions to take are being misreported to the public, who ultimately have the power to shape governmental and corporate action.
It also undermines public trust as well. With the media cherrypicking and presenting contrary views, science is portrayed as unreliable, arbitrary and ineffective, when in fact the picture, though uncertain in parts (the bits the media tend to concentrate on), is in the whole consistent and reliable.
Addendum: I found the latest paper on this result, Rachel Haywood. 2006: Relevance of Sunscreen Application Method, Visible Light and Sunlight Intensity to Free-Radical Protection: A Study of ex vivo Human Skin. Photochemistry and Photobiology: Vol. preprint. It's a pre-print so it hasn't been published yet. This paper basically repeats the results of the aforementioned paper, perhaps over a wider range of exposures and target preparations. The link between UVA/free-radicals and melanoma is still to be firmly established however.
So instead of concentrating on what isn't science, I thought I might add a few words on science as a framework of reasoning and for making sense of a complex world. The value of science isn't just in the spinoffs, the application of the results of science, but as a concerted endeavour to understand the whole universe, from the stars, the ground upon which we walk, the life around us, and to the ends of time. My thoughts are very general and broad, there are exceptions to everything of course but in the main, I think science as a whole possess the following properties.
Science is a process. To make a tenuous analogy, the economy is a process, rather than an object. Science is continually evolving, it changes in response to many factors, some internal, but most importantly to external input, observation and experiment. Without this, science would be a sterile, onanistic activity. There are no received truths, the final arbiter is nature itself. Science is both reactive and proactive. Reactive in the sense that science must continually accommodate new results. Proactive in that it seeks to find the new results which would change science itself. The least interesting science is where there is nothing new to discover.
Science is introspective. Science is not, contrary to popular perception, about absolute certainty and truth. The hallmarks of a vigorous science is constructive debate and discussion. By subjecting our theories and results to the greatest scrutiny, the more confident we can be about their reliability if they pass these tests. What may seem to outsiders like indecision, qualification, dithering and caution, is actually thoughtful consideration of the complexities of the subject. It's not a case of right or wrong usually, rather a case of less or more valid in a particular context. This can be confusing to an outsider who expects the opposite.
Science is like betting. A good punter studies the form, tries to gather as much information about past performances as well as takes into account current conditions to make an informed guess as to future performance. This is what science does with the world. It studies how the world works and tries to infers the mechanisms by which it functions and hence hopefully how it will work in given circumstances. Our theories are bets on what would happen. The more learn about the world, the more we can refine our models and be more confident about our wagers. Let's give a simple example, related to Dawkins' famous quote (River Out of Eden):
Show me a cultural relativist at thirty thousand feet and I'll show you a hypocrite. Airplanes are built according to scientific principles and they work. They stay aloft and they get you to a chosen destination. Airplanes built to tribal or mythological specifications such as the dummy planes of the Cargo cults in jungle clearings or the bees-waxed wings of Icarus don't.
Why do we generally not step off the edges of cliffs? It's because it is a reasonable assumption that gravity exists and rapid deceleration at the end one's vertical journey is not good for the human body. Why do we think that it is reasonable to "believe" in gravity? Not because we have Einstein's Field Equations but because historically, objects which are without support generally accelerate towards the ground. Science is just a small step further from this in that it is a systematic way of coming to a justifiable or reasonable assumption about how things will behave. If you're even slightly curious, you may want to investigate how long it take an object to fall a certain distance. You could extend this to the case when you give the object some initial velocity. How about horizontal velocity etc? Galileo did some experiments and came up with a set of rules which seemed to describe the trajectory of ballistic objects. The ancient Greek philosopher Aristotle had some ideas on the same subject. However, he based his conclusions on how objects ought to behave, rather than how they actually do behave. Unsurprisingly, ballistic trajectories envisioned by medieval engineers and gunners based upon Aristotelian ideas were inconsistent with Galileo's calculations, and what were later incorporated in Newton's Laws of Motion.
Science is a process by which we come to such conclusions about the world. However, these conclusions are aren't absolute truths, each comes with their own caveats and degrees of certainty, depending upon the results, theory and the interplay between them, and how they fit within the entire structure of scientific thought. Some scientific conclusions are so certain that it would be perverse to believe otherwise, e.g. the fact of gravity. Similarly certain conclusions are that the Earth is not flat, the Earth revolves around the Sun, the existence of atoms, evolutionary change, and local realism is not a good physical model. Down the spectrum, there are conclusions which are less certain, but still reasonable to take as working hypotheses, the Standard Model of particle physics is one example. At the edge of what could conceivably be called science (rather than mathematical speculation) is String Theory.
One could liken this attitude to Bayesian analysis. Given all the observations and experiments that have ever occurred, what is the post priori probability that a given outcome is likely? Science represents our best guess given everything we know (not to mention a consistent framework in which to place such knowledge in context). Being unscientific is ignoring the evidence and betting on the outsider when the payoff is not worth the risk (cf. MMR).
I think it's important to try to impress upon the public why scientists accept the validity of their results, and why they all come with degrees of uncertainty. I guess it's a fundamental worldview in which one have to accept that issues are not black and white, we live in a complex world and that its explanations may not be reducible to a sound bite. However, we're instinctual creatures, prone to acting on gut feelings about what is "right" or "wrong". Getting the public to fight our natural human instincts and be rational may be the greatest continuing battle for science.
I have a large version of this up in the common room of the building which is shared with some fluid dynamicists. I often get questions from them and their visitors about whether it is a real photo, or maybe I've been a bit clever with computer rendering or Photoshop. In fact, it's one of my earliest photos, when I was just getting into photography. To me, the photo invokes a connotation of black holes and gravity waves, ripples in space-time. The relationship isn't so far fetched, acoustic black holes have been proposed as systems in which to test general relativistic predictions on the Earth.
Friday, 21 July 2006
I am a theoretical physicist in an emerging field of enquiry. My day to day job involves investigating how we can utilise the quantum nature of matter and light to perform information processing. My main interests are in finding ways of getting around the deleterious effects of decoherence in various implementations of quantum computation and in characterising the quantumness of states and processes through interference phenomena. Of course, you can't be involved in quantum theory without bumping into questions of interpretations and foundations, but I try to leave the core issues to those more philosophically inclined. I may, from time to time, comment on particularly interesting paper which come to my attention. The whole field very broad so I apologise for any glaring omissions.
Though I have felt that blogs were little different from vanity self-publishing, I've recently stumbled upon some interesting science blogs which show that they can actually be informative and not simply the ramblings of self-centred, glory-seeking, egoists;-). I make no hubristic assumptions that anyone will actually read my posts, but if you have happened upon these pages by accident or design, I hope you will enjoy whatever random jottings follow.