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Popularisation or Propaganda?

Posted in Science Politics, The Universe and Stuff with tags , , , on November 25, 2008 by telescoper

I was just reading a piece by Jim Al-Khalili in today’s Guardian online science section. Jim is Professor of Physics and of Public Engagement in Science at the University of Surrey. His piece seems to have been inspired by the new appointment of Marcus du Sautoy to a similar position at Oxford University recently vacated by Richard Dawkins. His message is essentially that scientists should not only be more active in popularising science but also do more to “defend our rational, secular society against the rising tide of irrationalism”.

The legitimate interface between science and society has many levels to it. One aspect is the simple need to explain what science tells us about the world in order that people can play an informed part in our increasingly technological society. Another is that there needs to be encouragement for (especially young) people to study science seriously and to make it their career in order to maintain the supply of scientists for the future. And then there is the issue of the wider cultural implications of science, its impact on other belief-systems (such as religions) other forms of endeavour (such as art and literature) and even for government.

I think virtually all scientists would agree with the need for engagement in at least the first two of these. In fact, I’m sure most scientists would love to have the chance to explain their work to a lay audience, but not all subjects are as accessible or inspirational as, say, astronomy. Unfortunately also, not all scientists are very good at this sort of thing. Some might even be counterproductive if inflicted on the public in this way. So it seems relatively natural that some people have had more success than others, and have thus become identified as “science communicators”. Although some scientists are a bit snobby about those who write popular books and give popular talks, most of us agree that this kind of work is vital.

Vital, yes, but there are dangers. The number of scientists involved in this sort of work is probably more limited than it should be owing to the laziness of the popular media, who generally can’t be bothered to look outside London and the South-East for friendly scientists. The broadsheet newspapers employ very few qualified specialists among their staff even on the science pages so it’s a battle to get meaningful scientific content into print in the mass media. Much that does appear is slavishly regurgitated from one of the press agencies who are kept well fed by the public relations experts employed by research laboratories and other science institutes.

These factors mean that what comes out in the media can be a distorted representation of the real scientific process. Head of research groups and laboratories are engaged in the increasingly difficult business of securing enough money to continue their work in these uncertain financial times. Producing lots of glossy press releases seems to be one way of raising the profile and gaining the attention of funding bodies. Most scientists do this with care, but sometimes the results are ludicrously exaggerated or simply wrong. Some of the claims circulating around the time the Large Hadron Collider was switched on definitely fell into one or more of those categories. I realise that there’s a difficult balance to be struck between simplicity and accuracy, and that errors can result from overenthusiasm rather than anything more sinister, but even so we should tread carefully if we want the public to engage with what science really is.

Most worryingly is the perceived need to demonstrate black-and-white certainty over issues which are considerably more complicated than that. This is another situation where science popularisation becomes science propaganda. I’m not sure whether the public actually wants its scientists to make pronouncements as if they were infallible oracles, but the media definitely do. Scientists sometimes become cast in the role of priests, which is dangerous, especially when a result is later shown to be false. Then the public don’t just lose faith with one particular scientist, but with the whole of science.

Science is not about certainty. What it is a method for dealing rationally with uncertainty. It is a pragmatic system primarily intended for making testable inferences about the world using measurable, quantitative data. Scientists look their most arrogant and dogmatic when they try to push science beyond the (relatively limited) boundaries of its applicability and to ride roughshod over alternative ways of dealing with wider issues including, yes, religion.

I don’t have any religious beliefs that anyone other than me would recognize as such. I am also a scientist. But I don’t see any reason why being a scientist or not being a scientist should have any implications for my (lack of) religious faith. God (whatever that means) is, by construction, orthogonal to science. I’m not at all opposed to scientists talking about their religion or their atheism in the public domain, but I don’t see why their opinions are of any more interest than anyone else’s in these matters.

This brings us to the third of Jim’s suggestions: that more scientists should follow Richard Dawkins’ lead and be champions of atheism in the public domain. As a matter of fact, I agree with some of Dawkins’ agenda, such as his argument for the separation of church and state, although I don’t feel his heavy-handed use of the vitriol in The God Delusion achieved anything particularly positive (except for his bank balance, perhaps). But I don’t think it’s right to assume that all scientists should follow his example. Their beliefs are their business. I don’t think we will be much better off if we simply replace one set of priests with another.

So there you have my plea for scientists to accept that science will never have all the answers. There will always be “aspects of human experience that, even in an age of astonishing scientific advance, remain beyond the reach of scientific explanation”.

Can I have the Templeton Prize now please?

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What about magnetic fields?

Posted in The Universe and Stuff with tags , , on November 20, 2008 by telescoper

If you’re stuck for a question to ask at the end of an astronomy seminar and don’t want to reveal the fact that you were asleep for most of it, there are some general questions that you can nearly always ask regardless of the topic of the talk without appearing foolish. A few years ago, “how would the presence of dust affect your conclusions?” was quite a good one, but the danger these days is that with the development of far-infrared and submillimetre instrumentation and the proliferation of people using it, this could actually have been the topic of the talk you just dozed through. However, no technological advances have threatened the viability of another old stalwart: “What about magnetic fields?”.

These thoughts came into my mind when I was listening to an excellent talk by Richard Ellis at the Royal Astronomical Society last Friday about the current state of play in the (very complicated) field of galaxy formation. I hasten to add that nobody there was sleeping. Well, not many.

In theory, galaxies condense out of the Big Bang as lumps of dark matter. Seeded by primordial density fluctuations and amplified by the action of gravity these are supposed to grow in a hierarchical, bottom-up fashion with little blobs forming first and then merging into larger objects. The physics of this process is relatively simple (at least if the dark matter is cold) as it involves only gravity.

But, by definition, the dark matter can’t be seen. At least not directly, though its presence can be inferred indirectly by dynamical measurements and gravitational lensing. What astronomers generally see is starlight, although it often arrives at the telescope in an unfamiliar part of the spectrum owing to the redshifting effect of the expansion of the Universe. The stars in galaxies sit inside the blobs of dark matter, which are usually called “haloes” although blobs is a better name. In art the whole purpose of a halo is that you can see it.

How stars form is a very complicated question to answer even when you’re asking about nearby stellar nurseries like the Orion Nebula. The basic idea is that a gas cloud cools and contracts, radiating away energy until it gets sufficiently hot that nuclear burning switches on and pressure is generated that can oppose further collapse. The early stages of this processs, though, involve very many imponderables. Star formation doesn’t just involve gravity but lots of other processes, including additional volumes of Landau & Lifshitz, such as hydrodynamics, radiative transfer and, yes, magnetic fields. Naively, despite the complicated physics, it might still be imagined that stars form in the little blobs of dark matter first and then gradually get incorporated in larger objects.

Unfortunately, as Richard Ellis pointed out, this naive picture doesn’t seem to work. Deep surveys of galaxies suggest that the most massive galaxies formed their stars quite early in the Big Bang and have been relatively quiescent since then, while smaller objects contain younger stars. In other words, pretty much the opposite of what one might have thought. This phenomenon (known appropriately in the time of the Credit Crunch as “downsizing”) suggests that something inhibits star formation early on in all but the largest of the largest haloes. It could be that powerful feedback from activity in the nuclear regions associated with a central black hole might do this, or it could be something a little less exotic such as stellar winds. Or it could be that the whole scheme is wrong in a more fundamental way. I personally wouldn’t go so far as to throw out the whole framework, as it has scored many successes, but it is definitely an open question what is going on.

Then I was reminded by a posting on the arxiv about an interesting paper that appeared in Nature last month by Art Wolfe and collaborators which revealed the presence of an enormously strong magnetic field in a galaxy at the relatively high redshift of 0.692. Actually it’s about 84 microGauss. OK, so this is just one object but the magnetic field in it is remarkably strong. It could be a freak occurence resulting from some kind of shock or bubble, but it does seem to fit in a pattern in which young galaxies generally seem to have much higher magnetic fields than previously expected. Obviously we need to know how many more such magnetic monsters are lurking out there.

So why are these results so surprising? Didn’t we already know galaxies have magnetic fields in them?

Well, yes we did. The Milky Way has a magnetic field with a strength of about 10 microGauss, much lower than that discovered by Wolfe et al. But the point is that if we understand them properly, galactic magnetic fields are supposed to be have been much lower in the past than they are now. The standard theoretical picture is that a (tiny) initial seed field is amplified by a kind of dynamo operating by virtue of the strong differential rotation in disk galaxies. This makes the field grow exponentially with time so that only a few rotations of the galaxy are needed to make a large field out of a small one. Eventually this dynamo probably quenches when the field has an energy density comparable to the gas in the galaxy (which is roughly the situation we find in our own Galaxy).

Hopefully you now see the problem. If the field is being wound up quickly then younger galaxies (those whose light comes to us from a long way away) should have much smaller magnetic fields than nearby ones. But they don’t seem to behave in this way. A few years ago, I wrote a paper about a model in which the galactic fields weren’t produced by a dynamo but were primordial in origin and large from the start. I might dust it off and look it again…

The mystery of the origin of galactic magnetic fields remains unsolved largely because, although we know magnetism exists, it is notoriously difficult to understand its behaviour when it is coupled to all the other messy things we have to deal with in astrophysics. It’s a kind of polar opposite of dark matter, which we don’t know (for sure) exists but which only acts through gravity so its behaviour is easier to model. This is the main reason why cosmological theorists prefer to think about dark matter rather than magnetic fields. I’d hazard a guess that this is one problem that won’t be resolved soon either. Things are complicated enough already!

It is also worth considering the possibility that magnetic fields might play a role in moderating the processes by which gas turns into stars within protogalaxies. At the very least, a magnetic field generates stresses that influence the onset of collapse. Although it is by no means obvious that they provide the required missing link between dark matter haloes and stars, we now have less excuse for continuing to ignore them.

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On First Looking into Chapman’s Homer

Posted in Poetry, The Universe and Stuff with tags , , on November 19, 2008 by telescoper

As a present to those who appear disgruntled by my comments about exoplanets here and there, this is from John Keats:

 

Much have I travell’d in the realms of gold,
    And many goodly states and kingdoms seen;
    Round many western islands have I been
Which bards in fealty to Apollo hold.
Oft of one wide expanse had I been told
    That deep-brow’d Homer ruled as his demesne;
    Yet did I never breathe its pure serene
Till I heard Chapman speak out loud and bold:
Then felt I like some watcher of the skies
    When a new planet swims into his ken;
Or like stout Cortez when with eagle eyes
    He star’d at the Pacific–and all his men
Look’d at each other with a wild surmise–
    Silent, upon a peak in Darien.
 

This famous sonnet was written in October 1816 and is considered the highlight of Keats’s first volume of poetry. It was originally a gift for his friend, Charles Cowden Clarke. The two men had spent an evening reading George Chapman’s superb 17th century translation of the Iliad and Odyssey.

Please note lines 9 and 10. I’m sure they capture the excitement of discovery although Keats probably wasn’t using the correct IAU nomenclature. I’m not sure about the bit about being “silent” either.

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Science and Stamp Collecting

Posted in Books, Talks and Reviews, The Universe and Stuff with tags , , on November 18, 2008 by telescoper

Musing over the comments posted on my (slightly ironic) blog item about exoplanetary ennui, I remembered a piece I wrote for the Times Literary Supplement last summer so I dusted it off, chopped it up, and updated it for presentation here because it expands a bit on the earlier contribution.

If the Sun were the size of a golf ball, then the Earth would be a speck of dust a few metres from it and the nearest star would be hundreds of kilometres away. And this is what it is like in the relatively crowded environment of the Milky Way. The unimaginable scale of our Universe means that astronomy has never really become an experimental science, but has largely remained an observational one, having more in common with, say, archaeology than chemistry or other laboratory-based disciplines. Consequently, even though it is perhaps the oldest science, it is also in some respects the least mature. The absence of the traditional interplay between theory and experiment, the inability to perform repeated experiments under slightly different conditions, and the sheer difficulty of measuring anything at all have stunted its development compared to younger fields. For this reason, one often finds in astronomy certain tendencies that other subjects have largely grown out of, such as an unhealthy mania for classification and nomenclature.

Taxonomy has its place within the scientific method: modern chemistry owes much to Dmitri Mendeleev‘s periodic table; botany could not have progressed without Linnaeus; and the theory of evolution was founded on Charles Darwin‘s painstaking studies on the Galapagos Islands. But arranging things in groups and giving them names does not in itself constitute scientific progress, no matter how systematically it is done. The great experimental physicist Ernest (Lord) Rutherford dismissed this kind of activity as not science but “stamp collecting”.

This brings us to the grand debate that took place in Prague in the summer of 2006 under the auspices of the International Astronomical Union. One of the problems before the IAU’s 26th General Assembly was what to do about the fact that recent investigations have revealed the presence of a number of objects orbiting the Sun that are ostensibly at least as worthy of the name “planet” as Pluto, which in our current textbooks is the ninth one out. Obviously, which objects should be called planets depends on how you define what a planet is. The solar system contains objects of all shapes and sizes, from tiny asteroids to immense gas giants such as Jupiter and Saturn. Where should one draw the line? The original proposal was to increase the number of planets to twelve by admitting some lowly new members to the club, but in the end the IAU decided to demote Pluto to the status of a “dwarf” planet thus restricting the number of true planets to eight. This was a controversial decision, at least in the United States, because the vital vote was taken on the last day of the meeting when most of the US delegates had to take flights home. Pluto was discovered by an American, Clyde Tombaugh, in 1930, so the decision deprived the nation of its only planet-discoverer.

The “no” decision hinged on the adoption of three criteria: that the object be round, i.e. have a shape determined by internal gravitational forces; that it should have cleared its own orbit of debris; and that it should be orbiting our own star, the Sun. None of these has any special scientific value; the resulting decision was therefore pretty arbitrary. Moreover, deep-space observations have led to the discovery of literally hundreds of planetlike objects orbiting other stars. These exoplanets offer much greater prospects for scientific progress into the general theory of planet formation than the few objects that happen to have formed in our particular vicinity, so why are they excluded from the definition? In any case, what have we learned scientifically from the new nomenclature? Pluto is still the same object that it was before August 2006, and astronomers still don’t understand what one can infer from its own particular properties about the general process of planet formation.

So is Pluto a planet?

Who cares? In this case there really is nothing in a name. When I was asked this question on the telephone by a reporter I gave precisely that answer and he was shocked. I’m sure he thought that all that astronomers do is look at things and give them names. There are some that do that, of course, but most of us prefer doing proper science.

In the field of exoplanet research we are seeing real signs of maturity, although current studies are still firmly rooted in the “discovery” and “classificatuion” stage. Witness last weeks press interest in the first directly imaged exoplanets. I am well aware of the immense potential that those pictures have for stimulating interest in science, but there is still a long way to go before this field reaches its prime. That probably makes it an excellent area for young scientists to work in. But ultimately this youthful exuberance should give way to something a bit more serious, which is to go beyond what these discoveries are in themselves and ask what deeper questions they might answer.

One can see many other parallels in the history of astronomy, such as the discovery of quasars in the late 1950s. The first few of these must have generated a huge amount of excitement because they were not at all understood. Within a few years hundreds had been detected by radio observations but their nature remained unknown. The subsequent identification of redshifted hydrogen emission lines in the spectra of these objects led to them eventually being identified as very distant extragalactic sources of immense intrinsic power. By the 1980s quasars were identified as a particular type of active galaxy and placed within a general classification scheme that also involved blazars, Seyfert galaxies, and so on. Nowadays we have samples of tens of thousands of quasar spectra and the interest evolves around how the activity in their nucleus relates to the process of galaxy formation in an expanding Universe and how we can use these objects to map out the large-scale distribution of matter. To an outsider these tasks may seem less glamorous that the early days of quasar research, but that’s what science is like.

At the extreme end of the distance scale of astronomical investigation lies my own field of cosmology, the scientific study of the Universe as a whole. The scale of the solar system is challenging enough, but the cosmos is really big. Until recently, cosmology was so lacking in reliable observational input that it was thought of as a flaky offshoot of astronomy, more a branch of metaphysics than a proper scientific discipline, a paradise for theoreticians whose wildest speculations stood no chance of ever being tested with real measurements. Over the past twenty years or so, however, staggering advances in astronomical instrumentation have allowed astronomers to probe the darkest depths of space, capturing light that has travelled for almost 14 billion years on its way towards us. Theories are now so tightly constrained by these observations that there is very little room for manoeuvre. From this interplay between conjecture and refutation has emerged a cosmological framework that accounts, at least in a broad-brush sense, for how the Universe is constructed and how it is evolving.

There are some important gaps, including some puzzling anomalies, and the precise nature of many of its constituents is yet to be understood, but the establishment of the “concordance model” is a sign that cosmology really has come of age.

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When you’ve seen one planet….

Posted in The Universe and Stuff with tags on November 14, 2008 by telescoper

Rumours have been circulating for several days and now we have confirmation. The most exciting news in the history of the Universe! Planets exist! 

Well, actually, we knew that. We live on one. And anyway, the International Astronomical Union recently stipulated that planets could only be things orbiting the Sun.  Don’t ask me why. So the new things have to be called exoplanets. And over 300 hundred of these were known before today anyway.  A rose by any other name would smell as sweet, so we won’t worry about the taxonomy. But what’s the big deal?

2008111311What is different about the most recent observations, reported in today’s issue of Science, is that they involve direct detection (i.e. imaging) of exoplanets, not indirect inferences made by studying stellar wobbles. An example is shown here: the three red dots are the exoplanetary objects orbiting around the star HR 8799.

 Quite interesting.

But is every new detection of an exoplanet going to be hyped like this from now until doomsday? Or until the public gets thoroughly bored?  Might it not be better to wait until there’s a sufficiently large and unbiased sample that exoplaneticists can quit their stamp collecting and start doing some real science?

At least in cosmology nobody ever exaggerates the importance of their discoveries.

*cough*

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A Lop-sided Universe?

Posted in Bad Statistics, Cosmic Anomalies, The Universe and Stuff with tags , on November 9, 2008 by telescoper

Over on cosmic variance, I found an old post concerning the issue of whether there might be large-scale anomalies in the cosmic microwave background sky. I blogged about this some time ago, under the title of Is there an Elephant in the Room?, so it’s interesting to see a different take on it. Interest in this issue has been highlighted by a recent paper by Groeneboom & Eriksen that claims to have detected asymmetry in the distribution of fluctuations in the data from the Wilkinson Microwave Anisotropy Probe (WMAP) inconsistent with the predictions of the standard cosmological model. If this feature is truly of primordial origin then it is an extremely important discovery as it will (probably) require the introduction of new physics into our understanding of cosmology, and that will be exciting.

It is the job of theorists to invent new theories, and it is not at all a problem that these bits of evidence have generated a number of speculative ideas. Who knows? One of them may be right. I think it is the job of theoreticians to think as radically as possible about things like this. On the other hand, it is the observational evidence that counts in the end and we should be very conservative in how we treat that. This is what bothers me about this particular issue.

elongatedThe picture on the left shows a processed version of the WMAP fluctuation pattern designed to reveal the asymmetry, with the apparent preferred direction shown in red. This map shows the variation of the across the whole sky, and the claimed result is that the fluctuations are a bit larger around the red dots (which are 180 degrees apart) than in the regions at right angles to them.

It’s a slight effect, but everything in the picture is a slight effect as the CMB is extremely smooth to start with, the fluctuations in temperature being only about one part in a hundred thousand. The statistical analysis looks to me to be reasonably solid, so lets suppose that the claim is correct.scan

The picture on the right (courtesy of NASA/WMAP Science Team) shows the scan strategy followed by the WMAP satellite on the same projection of the sky. The experiment maps the whole sky by spinning its detectors in such a way that they point at all possible positions. The axis of this spin is chosen in a particular way so that it is aligned with the ecliptic poles (out of the plane of the solar system). It is in the nature of this procedure that it visits some places more than others (those at the ecliptic poles are scanned more often than those at the equator), hence the variation in signal-to-noise shown in the map. You can see that effect graphically in the picture: the regions near the North and South ecliptic poles have better signal to noise than the others.

The axis found by Groeneboom & Eriksen is not perfectly aligned with the ecliptic plane but it is pretty close. It seems a reasonable (if conservative) interpretation of this that the detected CMB anomaly could be due to an unknown systematic that has something to do either with the solar system (such as an unknown source of radiation, like cold dust) or the way the satellite scans. The WMAP team have worked immensely hard to isolate any such systematics so if this is such an effect then it must be very subtle to have escaped their powerful scrutiny. They’re all clever people and it’s a fabulous experiment, but that doesn’t mean that it is impossible that they have missed something.

Many of the comments that have been posted on cosmic variance relating to this question the statistical nature of the result. Of course we have only one sky available, so given the “randomness” of the fluctuations it is possible that freakish configurations occur by chance. This misses the essentially probabilistic nature of all science which I tried to describe in my book on probability From Cosmos to Chaos. We are always limited by noise and incompleteness but that doesn’t invalidate the scientific method. In cosmology these problems are writ large because of the nature of the subject, but there is no qualitative difference in the interplay between science and theory in cosmology compared with other sciences. It’s just less easy to get the evidence.

So the issue here, which is addressed only partially by Groeneboom % Eriksen, is whether a lop-sided universe is more probable than an isotropic one given the WMAP measurements. They use a properly consistent Bayesian argument to tackle this issue and form a reasonably strong conclusion that the answer is yes. As far as it goes, I think this is (probably) reasonable.

However, now imagine I don’t believe in anistropic cosmologies but instead have an idea that this is caused by an unknown systematic relating in some way to the ecliptic plane. Following the usual Bayesian logic I think it is clear that, although both can account for the data, my hypothesis must be even more probable than a lop-sided universe. There is no reason why a primordial effect should align so closely with the ecliptic plane, so there is one unexplained coincidence in the lop-sided-universe model, whereas my model neatly accounts for that fact without any freedom to adjust free parameters. Ockham’s razor is on my side.

So what can we do about this? The answer might be not very much. It is true that, soon, the Planck Surveyor will be launched and it will map the CMB sky againat higher resolution and sensitivity. On the other hand, it will not solve the problem that we only have one sky. The fact that it is a different experiment may yield clues to any residual systematics in the WMAP results, but if it has a similar scan strategy to WMAP, even Planck might not provide definitive answers.

I think this one may run and run!

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Parallel Lives

Posted in Music, The Universe and Stuff with tags , on November 6, 2008 by telescoper

I’ve just finished reading The Life of Charles Ives by Stuart Feder, which I bought some time ago with my Cambridge University Press author discount and I’ve had on my shelves without getting around to read it until this week. It’s a very interesting and informative biography of one of the strangest but most fascinating composers in the history of classical music.

Charles Ives was by any standards a daring musical innovator. Some of his compositions involve atonal structures and some involve different parts of the orchestra playing in different time signatures. He also wrote strange and wonderful piano pieces, including some which involved re-tuning the piano to obtain scales involving quarter-tones. Among this maelstrom of modern ideas he also liked to add quotations from folk songs and old hymns which gives his work a paradoxically nostalgic tinge.

His pieces are often extremely diffficult to play (so I’m told) and sometimes not that easy to listen to, but while he’s often perplexing he can also be exhilarating and very moving. Other composers might play off two musical ideas against each other, but Ives would smash them together and to hell with the dissonance. I think the wholeheartedness of his eccentricity is wonderful, but I know that some people think he was just a nut.. You’ll have to make your own mind up on that.

My favourite quote of his can be found scrawled on a hand-written score which he sent to his copyist:

“Please don’t try to make things nice! All the wrong notes are right. Just copy as I have – I want it that way.”

But the point of adding this post to my blog was that in the course of reading the biography, it struck me that there is a strange parallel between the life of this controversial and not-too-well known composer and that of Albert Einstein who is certainly better known, especially to people reading what purports to be a physics blog.

For one thing their lifespans coincide pretty closely. Charles Ives was born in 1874 and died in 1954; Albert Einstein lived from 1879 to 1955. Of course the one was born in America and the latter in Germany. One inhabited the world of music and the other science; Ives, in fact, made his living in the insurance business and only composed in his spare time while Einstein spent most of his career in academia, after a brief period working in a patent office. Not everything Ives wrote was published professionally and he also rewrote things extensively, so it is difficult to establish exact dates for things especially for a non-expert like me. In any case I don’t want to push things too far and try to argue that some spooky zeitgeist acted at a distance to summon the ideas from each of them in his own sphere. I just think it is curious to observe how similar their world lines were, at least in some respects.

We all know that Einstein’s “year of miracles” was 1905, during which he published classic papers on special relativity, brownian motion and the photoelectric effect. What was arguably Ives’ greatest composition, The Unanswered Question, was completed in 1906 (although it was revised later). This piece is subtitled “A Cosmic Landscape” and it’s a sort of meditation on the philosophical problem of existence: the muted strings (which are often positioned offstage in concert performances) symbolize silence while the solo trumpet evokes the individual struggling to find meaning within the void. Here’s a fine performance of this work recorded at La Scala in Milan, in which the strings are onstage while the trumpet is in the audience. I love the way that at the end nobody seems to know if they have finished!

The Unanswered Question is probably Ives’ greatest masterpiece, but it wasn’t the only work he composed in 1906. A companion piece called Central Park in the Dark also dates from that year and they are sometimes performed together as a kind of diptych which offers interesting contrasts. While the former is static and rather abstract, the latter is dynamic and programmatic (in that it includes realistic evocations of night-time sounds).

Einstein’s next great triumph was his General Theory of Relativity in 1915, an extension of the special theory to include gravity and accelerated motion, which which came only after years of hard work learning the required difficult mathematics. Ives too was hard at work for the next decade which resulted in other high points, although they didn’t make him a household name like Einstein. The Fourth Symphony is an extraordinary work which even the best orchestras find extremely difficult to perform. Even better in my view is Three Places in New England (completed in 1914) , which contains my own favourite bit of Ives. The last movement, The Housatonic at Stockbridge is very typical of his unique approach, with a beautifully paraphrased hymn tune floating over the top of complex meandering string figures until the piece ends in a tumultuous crescendo.

After this period, both Einstein and Ives carried on working in their respective domains, and even with similar preoccupations. Einstein was in search of a unified field theory that could unite gravity with the other forces of nature, although the approach led him away from the mainstream of conventional physics research and his later years he became an increasingly marginal figure.

By about 1920 Ives had written five full symphonies (four numbered ones and one called the Holidays Symphony) but his ambition beyond these was perhaps just as grandiose as Einstein’s: to create a so-called “Universe Symphony” which he described (in typically bewildering fashion) as

“A striving to present – to contemplate in tones rather than in music as such, that is – not exactly within the general term or meaning as it is so understood – to paint the creation, the mysterious beginnings of all things, known through God to man, to trace with tonal imprints the vastness, the spiritual eternities, from the great unknown to the great unknown.”

I guess such an ambitious project – to create an entirely new language of “tones” that could give expression to timeless eternity, a kind of musical theory of everything – was doomed to failure. Although Ives was an experienced symphonic composer he couldn’t find a way to realise his vision. Only fragments of the Universe Symphony remain (although various attempts have been made by others to complete it).

In fact, the end of Ives’ creative career was much more sudden and final than Einstein who, although he never again reached the heights he had scaled in 1915 – who could? – remained a productive and respected scientist until his death. Ives had a somewhat melancholic disposition and from time to time suffered from depression. By 1918 he already felt that his creative flame was faltering, but by 1926 the spark was extinguished completely. His wife, appropriately named Harmony, remembered the precise day when this happened at their townhouse in New York:

“He came downstairs one day with tears in his eyes, and said he couldn’t seem to compose anymore – nothing went well, nothing sounded right.”

Although Charles Ives lived almost another thirty years he never composed another piece of music after that day in 1926. I find that unbearably sad, but at least a lot of his work is available and now fairly widely played. Alongside the pieces I have mentioned, there are literally hundreds of songs, some of which are exceptionally beautiful, and dozens of smaller works including piano and violin sonatas.

Although they both lived in the same part of America for many years, I don’t think Charles Ives and Albert Einstein ever met. I wonder what they would have made of each other if they had?

If you believe in the multiverse, of course, then there is a part of it in which they do meet. Einstein was an enthusiastic violinist so there will even be a parallel world in which Einstein is playing the Ives’ Violin Sonata on Youtube.

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Theories of Everything

Posted in The Universe and Stuff with tags , on October 18, 2008 by telescoper

A string theorist arrives home one evening. When he goes into his house, his wife tells him that she’s hired a private detective who has been following him for the past week and she now knows he’s having an affair with another woman.

“But darling…” says the string theorist. “I can explain everything.”

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Nobel Sur-prize

Posted in The Universe and Stuff with tags , , on October 7, 2008 by telescoper

I was waiting for the letter from Stockholm, but it didn’t come. Maybe next year…

Anyway, this year’s Nobel Prize for Physics has been awarded to Yoichiro Nambu (half the prize) and the other half is split between
Makoto Kobayashi and Toshihide Maskawa. All three are extremely distinguished physicists and their contributions certainly deserve to be rewarded. But, in the case of Kobayashi and Maskawa, the Nobel Foundation has made a startling omission that I really can’t understand at all and which even threatens to undermine the prestige of the prize itself.

The work for which these two were given half the Nobel Prize this year relates to the broken symmetry displayed by weak interactions between quarks. We now know that there are three generations of quarks, each containing quarks of two different flavours. The first generation contains the up (u) and the down (d), the second the strange (s) and the charmed (c), and the third has the bottom (b) and the top (t). OK, so the names are daft, but physicists have never been good at names.

The world of quarks is different to penetrate becauses quarks interact via the strong force which binds them close together into hadrons which are either baryons (three quarks) or mesons (a quark and an anti-quark).

But there are other kinds of particles too, the leptons. These are also arranged in three generations but each of these families contains a charged particle and a neutrino. The first generation is an electron and a neutrino, the second a muon and its neutrino, and the third has the tau and another neutrino. One might think that the three quark generations and the three lepton generations might have some deep equivalence between them, but leptons aren’t quarks so can’t interact at all by the strong interaction. Quarks and leptons can both interact via the weak interaction (the force responsible for radioactive beta-decay).

Weak interactions between leptons conserve generation, so the total number of particles of electron type is never changed (ignoring neutrino oscillations, which have only relatively recently been discovered). It seemed natural to assume that weak interactions between quarks should do the same thing, forbidding processes that hop between generations. Unfortunately, however, this is not the case. There are weak interactions that appear to convert u and/or d quarks into c and/or s quarks, but these seem to be relatively feeble compared to interactions within a generation, which seem to happen with about the same strength for quarks as they do for leptons. This all suggests that there is some sort of symmetry lurking somewhere in there, but it’s not quite what one might have anticipated.

The explanation of this was proposed by Nicola Cabibbo who, using a model in which there are only two quark generations, developed the idea that states of pure quark flavour (“u” or “d”, say) are not really what the weak interaction “sees”. In other words, the quark flavour states are not proper eigenstates of the weak interaction. All that is needed is to imagine that the required eigenstates are a linear combination of the flavour states and, Bob’s your uncle, quark generation needn’t be conserved. This phenomenon is called Quark Mixing. What makes it simple for only two generations is that it can be described entirely by one number: the Cabibbo angle, which measures how much the quark flavour basis is misaligned with the weak interaction basis. The angle is small so the symmetry is only slightly broken.

Kobayashi and Maskawa generalized the work of Cabibbo to the case of three quark generations. That’s actually quite a substantial task as the description of mixing in this case requires not just a single number but a 3×3 matrix each of whose entries is complex. This matrix is universally called the Cabibbo-Kobayashi-Maskawa (CKM) matrix and it now crops up all over the standard model of particle physics.

And there’s the rub. Why on Earth was Cabibbo not awarded a share of this year’s prize? I was shocked and saddened to find out that he’d been passed over despite the fact that his work so obviously led the way. I can think of no reason why he was omitted. It’s outrageous. I even feel sorry for Kobayashi and Maskawa, because there is certain to be such an outcry about this gaffe that it may detract from their success.

But really…

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Wakeham Review

Posted in Science Politics, The Universe and Stuff with tags , , on October 1, 2008 by telescoper

Today is the day of publication of the Wakeham Review of the state of Physics in the United Kingdom. This report was commissioned by the Secretary of State for Innovation, Universities and Skills (DIUS) against the backdrop of the funding crisis that threatened to engulf the
Science and Technology Facilities Council (STFC) in December 2007 and which has led to drastic cuts in research grant funding in particle physics and astronomy throughout the country.

I started blogging a bit too late to join in the chorus of anger surrounding the handling of this crisis by STFC and especially by the behaviour of its Chief Executive, Keith Mason. An investigation of this by a parliamentary Select Committee stated that

“Substantial and urgent changes are now needed in the way in which the Council is run in order to restore confidence and to give it the leadership it desperately needs and has so far failed properly to receive”

If anyone was ever given a clear message that he should resign, this was it. But Keith Mason remains Chief Executive of STFC.

I hoped, therefore, to find some comment about this state of affairs in the Wakeham Review. I haven’t had time to read all of it, but most of it seems bland and rather self-congratulatory. It does, however, describe the strengths of astronomy and space science research in the UK, which is one of the areas placed in jeopardy by STFC’s cack-handed management and woeful lack of political nous. On the other hand, the UK has less impressive impact in other areas. Condensed matter physics was the research area in which most University-based physicists in the UK worked in 2001but their impact, at least in bibliometric terms, was and is unspectacular compared with other countries. Perhaps this is the reason why the number of condensed matter physicists submitted to the Research Assessment Exercise in 2008 has declined, while astronomy and astrophysics have increased.

The Wakeham review does not come to any clear conclusions on why some areas of physics are more popular than others, citing as possibilities laboratory costs and difficulties of attracting people into cross-disciplinary areas like biophysics or nanoscience. Since I’m not a member I don’t have to mince words like the panel did. I think some fields are popular because they are more interesting. And if people wanted to do chemistry or biology they wouldn’t have become physicists in the first place.

There are two paragraphs specifically about STFC, and they make very specific proposals although falling short of asking the current leadership to step down:

6. There is a need to ensure that there is coherence of planning of physics facilities and the allocation of physics research grants, so that research needs are closely aligned with facility provision. For that reason it is not desirable to separate former PPARC-like physics from the funding of its facilities. For this reason the Panel recommends that the current division of physics funding between Research Councils remains. Whilst recognising recent difficulties, the Panel believes that it is important that facilities provided for particle physics and astronomy researchers be directly tensioned with the budget for the research that will utilise those facilities. The current structure provides this tension in part of its remit. However, the panel believes that adding to this tension a further dimension of national facilities and a government Science and Innovation Campuses is just too much.

This is true but I think it’s only a small part of the problem.

The Panel recommends that:
a) the STFC be required at each CSR to bid for and allocate specific funds to former PPARC facilities and grant funding together.This would avoid the undesired tensioning of these grants and facilities support against national facilities and the project for the development of science and innovation campuses.

Good! But will this happen?

b) the existing structure should be allowed time to develop, given it was founded on the basis of extensive positive consultation. However, at an appropriate point following the review of STFC management currently being conducted by Dr David Grant, DIUS should commission a review to examine STFC operations.

*Sigh* Another review. Great.

The next one is a bit stronger:


7. The STFC’s governance structure must be representative of the community it serves in order to gain stakeholders’ confidence going forward.

“..stakeholders’ confidence going forward”? Ugh! Who wrote that bollocks?

The Panel believes that significant damage has been done to the UK’s international reputation in some areas of the discipline of physics following the furore that was generated by the manner, timescale of changes and announcement of recent STFC funding decisions.

You can say that again.

The Panel were very concerned at the make-up of the STFC Council, both in terms of the over representation of the executive and the lack of representation of the community it serves in comparison with other Research Councils. It is understood that this structure was deliberately adopted to deal with the distinct features of STFC that arose because of its multiple missions. However, this has not best served the scientific community in some branches of science whose input was at one level below the Council. This is in sharp distinction to the practice of other Research Councils.


The Panel recommends to DIUS that the membership of STFC’s Council be broadened to include more of the stakeholders in the science activity at the highest level, and to redress the balance between executive presence and non-executive oversight.

Somebody must have deleted the sentence about having to get a new Chief Executive.

I’m sure there’ll be a lot more on physics blogs when there’s been time to digest the whole report, and if I think I’ve missed anything at a first reading I may post some more myself.

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