Michael Heller

Polish physicist, philosopher and Roman Catholic priest Michael Heller, has just been awarded the £820,000 Templeton Prize. Michael invited me to Krakow in 2006 and 2007 to deliver a couple of papers, and I honestly can't think of a more deserving recipient.

Michael will be investing all his Templeton prize-winning money in the Copernicus Centre in Krakow, an institute whose raison d'etre will be 'philosophy in science', rather than 'philosophy of science'. I have remarked before that most physicists seem to be happy to write about philosophical issues, but do so without having first familiarised themselves with the relevant philosophical literature. As a consequence, they commit the same egregious philosophical errors over and over again. It would be nice, then, to think that something can be done to ameliorate this phenomenon.

Congratulations Michael!

The Wrong Trousers

Me trousers split at work today.

One minute everything was fine, and I was chatting to a female colleague, and the next I looked down to see that a gaping hole had opened up from below the zip, all the way round to the saddle point of the trouser-space. Now, whilst this colleague's attractions are undeniable and multifarious, on this occasion the explanation didn't lie with an unanticipated tumescence event. Rather, the effort I had expended moments earlier in shifting a number of filing cabinets, had obviously torn the stitching asunder.

One's first thoughts in such a situation are obviously: 'Why can't they teach these third-world kids to use a sewing machine properly?' Subsequently, however, I realised that I was close to a total trouser-failure scenario, and remedial action was necessary. Sellotape placed across the inside of the rent fabric offered a temporary solution, but a safety pin supplied by another colleague, (who himself had suffered a total trouser-failure event some months previously, and been forced home by the trauma) was less effective, and ultimately discarded.

I duly reduced the length of my gait, and struggled to the end of the day as best I could.

Evilution

Those wishing to gain an insight into the minds of those on the religious right-wing in North America, may be, in equal measures, enlightened, amused, and disturbed by this diagram, produced by the Pittsburgh Creation Society.

It seems that the theory of evolution by natural selection, sustained by nutritious sin, is not only responsible for all the ills of society, but is also responsible for inflation, moral education, women and children's liberation, 'dirty books', and even 'hard rock'.

Which reminds me of the time that Ned Flanders went to what he claimed was a Christian Rock concert. On returning from the 'Chris Rock' gig, Ned confessed to having enjoyed the event, but also expressed some surprise at the frequent use of the f-word.

The Physics of NASCAR

With the exception of the characters in Frasier, America doesn't do sophistication. Nowhere is this more apparent than in the nature of its premier motorsport category, NASCAR, a form of stock-car racing. Simply put, the most popular form of motorsport in the USA is the type of thing which, in the 1970s, World of Sport and Dickie Davis would have spurned in favour of a demolition derby from Wimbledon.

Whilst Formula 1 cars are manufactured from carbon-fibre, NASCAR vehicles are made from sheet metal welded to steel tubing; the engine block has to be made of cast-iron; the valves in the engines must be operated by pushrods rather than overhead camshafts; and the air and fuel must be mixed by carburetors rather than fuel injection!

However, partly because of the ancient and alien nature of the technology employed in NASCAR, and also because its author, Diandra Leslie-Pelecky, is a brilliant scientific expositor, this is a fantastic book, and one which, I predict, will win awards within the 'popular science' genre.
Diandra covers unfashionable topics such as the physical chemistry of steel and paint and fuel, with elan and panache, and I found myself learning new things, like this, on virtually every page:

Water-based paint, like latex house paint, has a polymer binder and pigment suspended in water. You brush or roll the paint on the wall, and when the water evaporates, the polymers hold the pigment to the surface like bungee cords hold down a load in a pickup truck...Cars...use acrylic urethane paints...Unlike latex paint, acrylic urethane paint comes in two parts. The first part is an acrylic-based resin that contains the pigment and a polymer, and the second part is a hardener or catalyst. Neither part is paint by itself-they don't become paint until they are mixed and a chemical reaction occurs...Acrylic-urethane paint dries in two stages. First the [volatile organic compounds] in which the pigment and binder were dispersed start to evaporate. The second step is crosslinking, where the acrylic-urethane polymers form chemical bonds with each other. The resulting polymer network has a hard, glossy finish.

CP-violation

The redoubtable Bryan Appleyard writes a nice piece for the Sunday Times on supercomputer simulations of CP-violation in quantum chromodynamics.

In particle physics, a CP transformation is the combined operation which swaps positive charges and negative charges (Charge conjugation), and swaps right-handed particle states and left-handed particle states (Parity reversal). Given a left-handed, negatively charged particle, the corresponding antiparticle is a right-handed, positively charged particle. CP-violation occurs when particle processes are not invariant under a CP transformation. CP-violation is necessary to explain the asymmetry present in the early universe between the amount of matter and the amount of antimatter. However, whilst the standard model of particle physics predicts CP-violation in electroweak processes, and this CP-violation has been experimentally observed, the order of the violation is insufficient to account for the matter-antimatter asymmetry. The standard model is also capable of representing strong force CP-violation, but this has not been experimentally observed, and, once again, it transpires that this CP-violation, even if it does exist, cannot account for the exact magnitude of the matter-antimatter asymmetry in the early universe.

It seems then, that an explanation for the matter-antimatter asymmetry will reside in a Grand Unified Theory (GUT). Such a theory goes beyond the standard model by unifying the strong force with the electroweak force. (Note that a GUT does not incorporate gravity, and should not be confused with a Theory of Everything, which does just that.) CP-violation in a GUT will, it appears, be necessary to explain the matter-antimatter asymmetry. When energy densities in the early universe were sufficiently high, it is thought that the strong and electroweak forces were unified, and that particles mediating the unified force passed between quarks and leptons, permitting transmutations between these particles. If these reactions possessed CP-violation, then it could well explain the presence of a matter-antimatter asymmetry at the end of the GUT era.

Note, incidentally, that Appleyard's article equates the question 'Why was there more matter than antimatter in the early universe?' with the question 'Why is there something rather than nothing?' This is rather misleading. If there had been an exactly equal amount of matter and antimatter in the early universe, all the mass in the early universe would have been converted into a sea of photons (i.e., radiative energy). One would therefore have a space-time replete with energy, and although there would be no matter as such, this is hardly the same thing as nothing at all.

CP-Violation Standard Model Something rather than nothing Grand Unified Theories Bryan Appleyard

The Joint European Torus

Whilst the prospect of controllable fusion power remains out of reach, the technology employed to pursue this goal is quite fascinating.

Consider, for example, the Joint European Torus (JET), at UKAEA's Culham laboratory in Oxfordshire. This doughnut-shaped vessel, called a tokamak, is designed to confine a plasma of deuterium and tritium with the use of magnetic fields. The deuterium and tritium nuclei will fuse at the high temperatures created in a plasma, and release energy in two forms: neutrons and helium nuclei. The ultimate intention is that the energy carried by the neutrons can be used to heat the water in a jacket around the tokamak, and the steam energy from this can then be used to, say, power turbines that generate electricity. In principle, the energy carried by the helium nuclei is then sufficient to sustain the temperature of the plasma, and thereby make the fusion reaction self-sustaining once started.

What is particularly fascinating about JET is the way in which the magnetic fields are generated. To confine the plasma, a helical magnetic field is generated inside the tokamak. As a consequence, the charged deuterium and tritium nuclei in the plasma follow spiral trajectories inside the vessel. To generate this helical magnetic field, two distinct components are generated by distinct mechanisms:

Firstly, a 'toroidal' magnetic field is generated by superconducting magnets around the tokamak. This magnetic field is essentially generated in accordance with Ampere's law, in the same manner that a magnetic field is generated in the interior of a solenoid.

The toroidal field provides the longitudinal component to the resultant magnetic field. The total field is the sum of the toroidal field and a 'poloidal' field, which provides a latitudinal component to the resultant field. The poloidal field is generated by a changing current in a coil within the hole of the doughnut. To understand this requires some further background in electromagnetism:

An electric current creates a magnetic field, and in particular, creates something called magnetic flux, which is the integral of the magnetic field over a surface area. If a changing electric current is generated in a coil, then this generates a changing magnetic flux, and by magnetic induction, this will generate a current in another circuit. (This is the same principle by which a transformer operates).

In the case of a tokamak, the electrons in the plasma constitute the secondary circuit, and the changing current in the inner coil generates a toroidal electric field, which drives a longitudinal electron current in the plasma. Just like the current through a copper wire, this current generates a circular magnetic field in the perpendicular plane. This is the poloidal magnetic field, which generates the latitudinal component to the magnetic field controlling the trajectories of the deuterium and tritium nuclei.

Karl Pilkington on art

Karl Pilkington, as I might have mentioned before, is something of a hero of mine. Here, he visits the Hayward Gallery, and chats to some artists. His interview with one David Shrigley, in particular, is priceless. Shrigley tries to argue at one stage that an artist doesn't need to be able to draw well, in the same way that a guitarist in a band doesn't need to be able to play the guitar well.

Now, I'm no expert on music, but I reckon that Brian May, Jimi Hendrix, and the woolly-capped fellow from U2, can probably all play the guitar quite well, and that they had to learn their craft first, and then build the art upon the craft. A concept which seems to find little favour in modern art...

Gauging What's Real

I'm currently reading Gauging What's Real, by the philosopher of physics Richard Healey. This is an excellent treatise on the interpretation of classical and quantized gauge field theories. These theories are the prevailing theoretical paradigm employed in the standard model of particle physics. In fact, Healey's book forms the perfect counterpoint to my own, for whilst the balance of exposition in my own book is about 75% mathematical structures, 25% philosophy, the balance is somewhat reversed in Healey's text.

One of the criticisms I would make is that Healey's account of the mathematics of gauge field theory fails to employ the far simpler approach pioneered by Andrzej Derdzinski. The essence of Derdzinski's approach is that an interaction can be represented by an interaction bundle δ, a free particle field can be represented by a free-particle bundle σ, and the interacting particle field can be typically represented by the tensor product bundle δ ⊗ σ.

Nevetheless, Healey's book is much recommended.

Monday's sunset

The major enviro-aesthetic event of the week was surely Monday's spectacular Wagnerian sunset. During the day, the sky was bereft of cloud and haze, and, from a West Berkshire perspective, aircraft contrails carved deep white furrows across a field of pure azure overhead. After the Sun slid beneath the rim of the horizon, a forboding golden glow bathed the entire Western hemisphere of the clear cold sky, silhouetting the stark dendritic outlines of the Wintering trees.

Is it abnormal to be normal?

I think it's true to say that most of us, when we are young, dream of growing up to become statisticians. Sadly, very few of us chase that dream, and instead we grow up to become, say, premiership footballers or Grand Prix drivers. Nevertheless, there are a select few who persist, and who consequently spend their working lives looking at random variables, probability density functions, and cumulative distribution functions. Still, my beating heart.

Needless to say, statistics doesn't really do it for me. The problem with statistics, as a branch of mathematics, is that its value derives largely from its practical utility, not the intrinsic interest of its mathematical structures. Whilst statistics has vital application in all branches of science, finance and commerce, it is precisely this universality and utility which divest it of intrinsic interest. Statistics performs a service for other sciences, rather than being of value in its own right.

Nevertheless, any subject can be interesting once you tunnel sufficiently deeply, so consider the following well-known statistical scientific truism:

If a number of independent random variables combine in an additive fashion, then the collective result is a normal distribution. (i.e., a bell-shaped, Gaussian distribution).

If a number of independent random variables combine in a multiplicative fashion, then the collective result is a lognormal distribution. (i.e., a distribution whose logarithm is a normal distribution).

Now, I'm not sure whether this common wisdom is really correct. As far as I can make out, the first clause in a simplified statement of the central limit theorem. This asserts that the sum of a collection of n independent and identically distributed random variables will converge to a normal distribution as n tends to infinity. The central limit theorem has one particularly important implication for measurement science and the estimation of measurement error:

Suppose that the variable to be measured has an arbitrary distribution, and suppose that one measures the value of the variable by taking a collection of sample measurements, each sample consisting of n measurements; if one calculates the mean value from each sample, then the distribution of sample means will converge to a normal distribution, centred upon the true value of the measured variable, as the size of the sample, n, tends to infinity. Hence, whatever the distribution of the variable being measured, whether it is normal or not, the collection of sample means will have a normal distribution. This is crucial, because it enables one to estimate the 95% or 99% confidence interval, (the uncertainty or measurement error), in a measurement estimate, using the simple formulae or tables of values associated with the normal distribution.

So far, so good. But in general, will a sum of independent random variables give a normal distribution? The central limit theorem doesn't entail that it will, for the central limit theorem requires the contributing random variables to be identically distributed. So what happens when a sum of independent random variables with different distributions is taken?

The second assertion, that a lognormal distribution results from random variables combining in a multiplicative fashion, also needs to be tightly qualified. The assertion is largely based upon the following property of the logarithmic function:

log (A x B) = log A + log B

Thus, given a collection of independent random variables with identical distributions, their product will possess a distribution well-approximated by the logarithm of a normal distribution (applying the central limit theorem again). However, what if the collection of variables are not identically distributed?

Moreover, it has been noted that if the number of steps in a multiplicative process is itself subject to a statistical distribution, then the result will not necessarily be a lognormal distribution. For example, if the number of steps in a multiplicative process is subject to a geometric distribution (a discrete version of the exponential distribution), then whilst the body of the distribution will be lognormal, the tails will exhibit power law behaviour. That's interesting.

Sheila law

It is time to face up to the fact that there are large communities of young women in this country who respect not the conventional mores and manners of English society, but are beholden instead to a set of principles called Sheila law. Named after the colloquial term for an Australian woman, Sheila law attributes highest-value to a life of foul-mouthed, heavy-drinking, promiscuous behaviour. Those who subscribe to Sheila law regard the whole world as governed by Sheila law, and reject other standards of behaviour.

Sheila law is especially insidious because it is intolerant to all forms of criticism. Any expression of reproach directed towards those who live under Sheila law is met with aggression, hysteria and abuse.

One moral code for everybody would be something of a danger, and it is time for a constructive accommodation with some aspects of Sheila law. It seems inevitable that at least some form of Sheila law will be incorporated permanently into English mores and morality, and officially recognising this will improve relations with young modern females.

We need to look at Sheila law with a clear eye and not imagine, either, that we know exactly what we mean by Sheila law and just associate it with Australian women, or whatever. I do not think we should instantly spring to the conclusion that the whole of that world of modern female morality and practice is somehow monstrously incompatible with human dignity and respect, just because it doesn't immediately fit with how we understand it.