Friday, August 28, 2015

Songwriting by numbers

Can a crowd write a song? That’s what an online experiment by computer programmer Brendon Ferris in the Dominican Republic is hoping to determine. Users are invited to vote on the notes of a melody, one note at a time, and the most popular choice secures the next note. The melody is selected to fit an anodyne chord sequence, and as far as I can make out the choices of notes are restricted to those in the major scale of C, the key signature of the composition. I’m not sure if the notes are allowed to stray out of the single octave range beginning on middle C (the New Scientist article provides very few details), but so far they haven’t. In other words, the rules are set up to ensure that this will be a pretty crappy song come what may, with all the melodic invention and vocal range of Morrissey (oh ouch, that’s not going to be popular!).

Even putting that aside, the experiment bears no relation to how music is composed. No one decides on a melody note by note, or at least not outside of the extremes of, say, total serialism, where everything is determined algorithmically. Neither do we hear a melody that way. We group or “chunk” the notes into phrases, and one of the most salient aspects of a melodic line that we attend to – it’s what infants first discern, irrespective of the exact relationships between successive pitches – is the overall contour. Does it go up or down? Is the pitch jump a big or small one? The melodic phrase is, in general, a single meaningful unit, and its musicality disappears once it is atomized into notes. The very basis of our musicality lies in our propensity to arrange sound stimuli into groups: to bind notes together.

But this doesn’t mean that the experiment is worthless (even if it’s worthless as music). It potentially raises some interesting questions (though as I say below, the answers in this case are highly compromised by the constraints). Will this democratic approach to making melody result in a tune that shares the characteristics of other conventional tonal melodies? In other words, can the crowd as a whole intuit the “rules” that seem empirically to guide melodic composition? It seems that to a certain extent they can. For example:

- the crowdsourced melody (to the extent that can be judged so far) exhibits the same kind of arch contour as many common tunes (think of “Ode to Joy” or “The Grand Old Duke of York”, say), rising at the start and then falling at the end of the phrase.

- the contours tend to be fairly smooth: an ascent, once started, persists for several notes in the same direction, before eventually reversing.

- the statistics of pitch jumps between one note and the next exhibit the same general pattern, within the limited statistics so far, as is seen for music pretty universally: that’s to say, there are more small pitch steps than large ones, with most being just zero, one or two semitones (especially two, since this corresponds to the distance between most successive note pairs in the diatonic scale). Here’s the comparison: the statistics for a sample of Western classical music are shown in grey, the thick black line is for this song:

But there are some anomalies, like those weird downward jumps of a seventh, which I suspect are a consequence of a silly restriction on the span of the allowed note to exclude the upper note of the tonic octave: you have to go back down to C because you can’t go up. So perhaps all we really learn in this case is totally unsurprising: people have assimilated enough from nursery rhymes not to be picking notes at random or putting rests in weird places, they have intuited some basic principles of harmony (so that we’re not getting B naturals against an F chord), and that if you permit only the blandest of note choices against the blandest of chord sequences, you’ll get a tune that is of no real interest to anyone.

That’s the opposite of what Ferris was hoping for. “My way of thinking was, if the crowd decides what the next note is, then there must be something there that appeals to the most people,” he has said. “The song should sound good to everybody.” But even if the rules weren’t so badly chosen, this totally misunderstands what music is about. What snags our attention is not the obvious, the consensual, the average, but the unusual, the unexpected. But that can’t be arbitrary: there are also rules of a sort that help to make the unexpected work and prevent it from seeming unmotivated. Whether the crowd could, if given the right options, find its way to that sort of inventiveness remains to be seen; I’d be astonished if it could do so note by note.

Something of this same nature was tried before, with more insight, by the avant-garde jazz musician David Soldier, who is the pseudonym of the neuroscientist David Sulzer at Columbia University. Sulzer wrote a song based on surveys of hundreds of people to discover what elements, such as instrumentation, tempo and lyrics they liked best. He called the result "Most Wanted Song". I haven’t heard it myself, but some people have described it as a sickly abomination, while others have said that it sounds a bit like Celine Dion. Which I suppose is the same thing.

Sulzer’s whole point is that trying to define the perfect song according to some kind of measure of popularity is liable to end badly. I think Ferris is discovering that too.

Thursday, August 20, 2015

The cost of faking it

Here, a little belatedly, is my July column for Nature Materials, which considers the issues around bioprinting of fake rhino horn.


Debates about distinctions between “natural” and “synthetic” materials date back to antiquity, when Plato and Aristotle wondered if human “art” can rival that of nature. Scepticism about alchemists’ claims to make gold in the Middle Ages weren’t so much about whether their gold was “real” but whether it could compare in quality to natural gold. Such questions persisted into the modern age, for example in painters’ initial suspicions of synthetic ultramarine and in current consumer confusion over the integrity of synthesized natural products such as vitamin C.

It is all too easy for materials technologists to overlook the fact that what to them seems like a question of chemical identity is for users often as much a matter of symbolism. Luxury materials become such because of their cost, not their composition, while attitudes to the synthetic/natural distinction are hostage to changing fashions and values. The market for fake fur expanded in the 1970s as a result of a greater awareness of animal conservation and cruelty, but providing a synthetic alternative was not without complications and controversy. Some animal-rights groups argue that even fakes perpetuate an aesthetic that feeds the real-fur market, while recently there has been a rise in real fur being passed off as faux – a striking inversion of values – to capture the market of “ethical” fur fans. The moral – familiar to marketeers and economists if less so to materials scientists – is that market forces are dictated by much more than chemical composition.

These considerations resonate strongly in the current debate over plans by Seattle-based bioengineering company Pembient to use 3D printing for making fake rhinoceros horn from keratin. The company hopes to reduce rhino poaching by providing a synthetic alternative that, by some accounts, is virtually indistinguishable in composition, appearance and smell from the real thing. It claims that 45% of rhino horn traders have said they would buy the substitute. How to interpret that figure, even taken at face value, is unclear: will it help save the rhino, or does it show that over half of the buyers value something more than material identity? In the black-market Chinese and Vietnamese medicines that use the horn, it is supposed to imbue the drugs with an essence of the wild animal’s vitality: it is not just an ingredient in the same sense as egg is a part of cake mix, but imparts potency and status.

The same is true of the tiger bone traded illegally for medicines and wine. Even providing the real thing in a way that purports to curb the threat to wildlife, as for example when tigers are farmed in China to supposedly relieve the pressure on wild populations, can backfire in the marketplace: some experts say that tiger farming has revitalized what was a waning demand.

Critics of Pembient’s plans – the company intends to print tiger bone too – make similar complaints, saying that the objective should be to change the culture that creates a demand for these products rather than pandering to it. There’s surely a risk here of unintended outcomes in manipulating markets, but also a need to remember that materials, when they enter culture, become more than what they’re made of.

Thursday, July 30, 2015

Liquid-state particle physics

Here’s my latest column for Nature Materials.


The ability of condensed-matter physics to offer models for fundamental and particle physics has a distinguished history. Arguably it commenced with the liquid-droplet model of the atomic nucleus formulated in 1936 by Niels Bohr, which provided a simple approximation for thinking about nuclear stability and fission in terms of familiar concepts such as surface tension and heat of vaporization. Since then, real materials systems have offered all manner of laboratory analogues for exploring fundamental physical phenomena that lie outside the range of direct experimentation: for example, the use of liquid crystals to mimic the topological defects of cosmic strings and monopoles [1], the representation of graphene’s electronic structure in terms of massless relativistic Dirac fermions [2], or the way topological insulators made from oxide materials might manifest the same properties as Majorana fermions, putative spin-½ particles that are their own antiparticles [3].

These cases and others supply an elegant demonstration that physics is unified not so much by reduction to a small set of underlying equations describing its most fundamental entities, but by universal principles operating at many scales, of which symmetry breaking, phase transitions and collective phenomena are the most obvious. It’s perhaps curious, then, that particle physics has traditionally focused on individual rather than collective states – as Ollitrault has recently put it, “on rare events and the discovery of new elementary particles, rather than the “bulk” of particles” [4]. One indication that bulk properties are as important for high-energy physics as for materials science, he suggests, is the new discovery by the CMS Collaboration at CERN in Geneva that the plasma of quarks and gluons created by a proton collision with a lead nucleus has emergent features characteristic of a liquid [5].

It was initially expected that the quark-gluon plasma (QGP) – a soup of the fundamental constituents of nucleons – produced in collisions of heavy nuclei would resemble a gas. In this case, as in an ideal gas, the “bulk” properties of the plasma can be derived rather straightforwardly from those of its individual components. But instead the QGP turns out to be more like a liquid, in which many-body effects can’t be neglected.

Shades of Bohr, indeed. But how many many-body terms are relevant? Earlier studies of the tiny blob of QGP formed in lead-proton collisions, containing just 1,000 or so fundamental particles, showed significant two-particle correlations [6]. But in an ordinary liquid, hydrodynamic flow produces coherent structures in which the motions of many molecules are correlated. The new CMS results show that the QGP also has small but measurable six- and eight-body correlations – suggestive of collective flow effects – that are evident in the variations in particle numbers with the azimuthal angle relative to the line of collision. The azimuthal variations indicate that this flow is anisotropic, and the CMS team proposes that the anisotropy comes from a hydrodynamic amplification of random quantum fluctuations of the colliding particles.

So exactly what kind of liquid is this? Since the strong force between quarks and gluons doesn’t diminish with distance, the QGP seems likely to be quite unlike any we know so far. But might it be within the wit of colloid scientists to tune inter-particle forces so as to create a simple laboratory analogue?

1. Davis, A.-C. & Brandenberger, R. Formation and Interactions of Topological Defects (Springer, New York, 2012).
2. Novoselov, K. S. et al., Nature 438, 197-200 (2005).
3. Fu, L. & Kane, C. L., Phys. Rev. Lett. 100, 096407 (2008).
4. Ollitrault, J.-Y., (2015) [here].
5. Khachatryan, V. et al. (CMS Collaboration), Phys. Rev. Lett. 115, 012301 (2015) [here].
6. CMS Collaboration, Phys. Lett. B 718, 795-814 (2013).

Added note: Jean-Yves Ollitrault reminds me that perhaps the best example of particle physics borrowing from condensed-matter physics is the Higgs mechanism, which was inspired by the model of conventional superconductivity.

Friday, July 24, 2015

Silence of the geronotologists

I was perhaps a bit cryptic in tweeting about my New Statesman piece on “the immortality business” (which I’m afraid I can’t put up here, but it should be online soon – and NS is always worth its modest cover price anyway). This is what I meant.

When I pester researchers for comments on a topic I’m writing about, I recognize of course that none is under the slightest obligation to respond. That they almost always do (even if it’s to apologize for being unable to help) is a testament to the extraordinary generosity of the research community, and is one of the abiding joys and privileges of writing about science – my impression is that some other disciplines don’t fully share this willingness to explain and discuss their work. Occasionally I do simply get no response at all from a researcher, although it is unusual that a gentle follow-up enquiry will not at least elicit an explanation that the person concerned is too busy or otherwise indisposed to comment.

That’s why my experience in writing this piece was so clearly anomalous. I contacted a large number of gerontologists and others working on ageing, explaining what I was trying to do with this piece. With the very few honourable exceptions named in my article, none responded at all. (One other did at least have the grace to pretend that this was “not really my field”, despite that being self-evidently untrue.) I am almost certain that this is because these folks have decided that any “journalist” contacting them while mentioning names like Aubrey de Grey wants to write another uncritical piece about how he and others like him are going to conquer ageing.

I can understand this fear, especially in the light of what I said in the article: some researchers feel that even allowing the immortalists the oxygen of publicity is counter-productive. But truly, chaps, burying your head in the sand is the worst way to deal with this. A blanket distrust of the press, while to some degree understandable, just takes us back to the bad old days of adversarial science communication, the kind of “us versus them” mentality that, several years ago, I saw John Sulston so dismayingly portray at a gathering of scientists and science writers. What researchers need to do instead is to be selective and discerning: to decide that all writers are going to recycle the same old rubbish is not only silly but damaging to the public communication of science. I would even venture to say that, in figuring out how to deal with the distortions and misrepresentations that science sometimes undoubtedly suffers from, scientists need help. While it is understandable that, say, IVF pioneer Robert Edwards should have bemoaned the way “Frankenstein or Faust or Jekyll… [loom] over every biological debate”, I see little indication that biologists and medics really know how to grapple with that fact rather than just complain about it. You really need to talk to us, guys – we will (some of us) do our very best to help.

Wednesday, July 22, 2015

Understanding the understanding of science

That the computer scientist Charles Simonyi has endowed a professorial chair at Oxford for the Public Understanding of Science seems a rather splendid thing, acknowledging as it does the cultural importance of science communication (which was for a long time disdained by some academics, as Carl Sagan knew only too well). Richard Dawkins was the natural choice for the first occupant of the position, and indeed it seems to have been created partly with him in mind.

When his incumbency ended and applications were invited for his successor, a few well-meaning folks told me “you should have a go!” I quickly assured them that I am simply not in that league. Little did I know, however, that should I have been overcome with mad delusions of grandeur, I’d not only have stood less than a cat’s chance in hell but would have been specifically excluded from consideration in the first place. The full text of Simonyi’s manifesto in creating the position is reproduced in the second volume of Dawkins’ autobiography, Brief Candle in the Dark. It doesn’t simply say, as it might quite reasonably have done, that the post is for academics and not professional science communicators. No, it goes out of its way to insult the latter. Get this, fellow science hacks:

The university chair is intended for accomplished scholars who have made original contributions to their field, and who are able to grasp the subject, when necessary, at the highest levels of abstraction. A populariser, on the other hand, focuses mainly on the size of the audience and frequently gets separated from the world of scholarship. Popularisers often write on immediate concerns or even fads. In some cases they seduced less educated audiences by offering a patronizingly oversimplified or exaggerated view of the state of the art or the scientific process itself. This is best seen in hindsight, as we remember the ‘giant brains’ computer books of yesteryear but I suspect many current science books will in time be recognized as having fallen into this category. While the role of populariser may [may, note] still be valuable, nevertheless it is not one supported by this chair.

OK, I won’t even get started in on this. Richard doesn’t reproduce this without comment, however. He says he wants to “call attention especially” to “the distinction between popularizers of science and scientists (with original scientific contributions to their credit) who also popularize.” It’s not clear why he does this, especially as the distinction is spurious for many reasons.

I might add that Simonyi also stipulates that “preference should be given to specialities which express or achieve their results mainly by symbolic manipulation, such as Particle physics, Molecular biology, Cosmology, Genetics, Computer Science, Linguistics, Brain research, and of course, Mathematics.” So stuff you, chemists and earth scientists. Actually, stuff you too, cell biologists, immunologists and many others.

It doesn’t much matter to the world that I find this citation offensive. I think it does matter that it displays such ignorance of what science communication is about. I would be much more troubled, however, if the chair were not currently occupied by such a profoundly apt, capable and broad-minded individual as Marcus du Sautoy. If it continues to attract incumbents of such quality, I guess we needn’t trouble ourselves too much about the attitudes of its founder and patron.

Friday, July 17, 2015

Dawkins and the Spotted Dick mystery

I have agreed, with some trepidation, to review volume 2 of Richard Dawkins’ autobiography, this one called Brief Candle in the Dark. I guess I figured it might be refreshing to return to the pre-God-bashing, pre-Twitter Dawkins, when he was rightly known primarily as our pre-eminent science communicator (who called out the idiocies of creationism). And on the whole it is: rather than appearing to be the polarizing caricature that Dawkins is often presented as today, he comes across so far in the book as simply a chap with appealing features as well as foibles, not least of which among the former being his touching generosity to students. Sure, there are Pooterish touches (note to editors: if I ever write anything autobiographical that includes the line “I think my speech went down quite well”, then I’m counting on you guys), but also a sense of the humane individual (not to mention the splendid writer) who these days it can be hard to discern behind all the controversy that surrounds him. I should add that I’m still only on page 50.

But there are also occasional glimpses of the Twitter-era Dawkins, springing out Hyde-like from the good Jekyllish doctor. I was particularly struck by a passage in which, apropos of nothing in particular, Dawkins tells us about a “care home for old people in England” at which a “local government inspector” banned the traditional pudding Spotted Dick from the menu on the grounds that its name was “sexist”. This looked to me for all the world like one of those apocryphal “PC gone mad” stories that the Daily Mail loves to run (and then occasionally retract a few weeks later in small print). Could it really be true?

Thee only item that comes up after a quick Google is one reported – well, what did you expect? – by the Daily Mail. There, the change in naming was not occasioned by a prudish, PC government inspector. The story says that staff in a council canteen were totally fed up with a few customers (one in particular) who kept on making lewd and childish remarks whenever Spotted Dick was on the menu, and so they decided to take matters into their own hands – with the extremely ill-advised idea of calling it instead Spotted Richard. A council official then rather shamefacedly decided to intervene and reverse this policy because it looked so silly (and because it was being reported as an example of political correctness). There was no mention of anyone finding the name sexist, nor of officialdom actually trying to be politically correct.

Some Twitter comments challenged Dawkins about this, and his response was that this was not the same story at all. Rather, the Spotted Dickgate that he heard was from “a personal acquaintance, personally vouched for,” and not the infamous Flintshire Spotted Dickgate. And that, it seems, is all we are going to get from him (though you might think he’d be curious about the parallels).

So you must make up your own minds, people. Was Dawkins’ acquaintance recounting what shows every sign of becoming an urban myth, or was this really a case of Spotted Dick strikes again? Can anyone, in any event, figure out how Spotted Dick could be construed as “sexist” – or even, to paraphrase Spinal Tap, as ”sexy”? The anecdote doesn’t really make sense.

Alleged political correctness has of course become one of Dawkins’ bĂȘte noirs (bĂȘtes noir?) – after all, it did for his good friend James Watson after Watson betrayed his racist views once too often, and it also came close to doing for his friend Tim Hunt (a much nicer man than Watson) after Tim said something stupidly sexist. Could it possibly be that it suited Dawkins to believe what he was told without feeling the need to inquire further?

If that’s so, it’s simply another example of the kind of confirmation bias that often leads scientists astray, as I discussed here. What is ironic is that this passage comes so soon after Dawkins has given us a rather nice account of the critical thinking that interview questions at Oxford aim to probe. But it’s one thing to be led to false conclusions in research by seeking out the answer you are already predisposed to find; it’s quite another to recycle an anecdote in a way that makes you sound like a ranter in the comments section of the Daily Mail website.

So pending a full disclosure of data and references, preferably in a major peer-reviewed journal, I propose we should avoid propagating the “Spotted Dick” meme, even if the inventor of memes himself repeats it. This has been a public service announcement.

Monday, July 13, 2015

Beckett's epic fail (again)

One of my esteemed colleagues recently finished a nice piece on careers in science by quoting Samuel Beckett: “Ever tried. Ever failed. No matter. Try again. Fail again. Fail better.” The sentiment is entirely laudable: you’ll get things wrong, but don’t be deterred – every time you attempt something and fail, you get a little better. Or something like that.

Yet whenever I see Beckett put to use this way, I can’t help thinking “Hmphrgh”. This is Beckett you’re quoting. Yes, Samuel Beckett. Does anyone believe that he was ever going to write a soundbite of fist-punching, keep-on-goin’ self-motivation?

The line comes, of course, from Beckett’s late work Worstward Ho. I say of course because that’s commonly acknowledged, but I wonder how many have seen or read Worstward Ho. It is, shall we say, opaque even by the standards of a master of opacity. Dense, you might say. Difficult. Now, I love Beckett and find him an intensely funny writer, but funny because of a wry bleakness that makes Will Self seem like a bouncing-bunny optimist. It’s a braver soul than me who will pronounce with certainty on what Beckett was driving at with “Fail better”, but I will bet a pint of Guinness that he did not intend this to be a boiled-down version of that pious little primary-school mantra “If at first you don’t succeed, try, try again.”

It’s wise not to get too po-faced and spluttery about this misappropriation, not least because Beckett would doubtless have appreciated the joke. We get the memes we seem to need, like the martyrdom of Giordano Bruno or the misuse of “deconstruct”, and I’d be a sad fool indeed to think that a blog comment is going to make the slightest difference in squelching them.

But it’s sad that the irony here is so seldom recognized. Indeed, what seems particularly sad is that the opportunity to take a more nuanced view of failure is bypassed by this bit of repurposed wisdom.

Mark O’Connell has a great piece on Slate, called “How Samuel Beckett became Silicon Valley’s life coach.” He says “What has happened here, I suppose, is that a small shard of a fragmentary and difficult work of literature has been salvaged from the darkness of its setting, sanded and smoothed of the jagged remnants of that context”. The result, O’Connell says, is that Beckett is pressed “into service as a kind of highbrow motivational thought-leader.” But in truth “his attitude toward success and failure was more complex and perverse than this interpretation suggests.” That’s surely true.

What, then, was that attitude? Maggi Dawn has a nice interpretation on her blog: “there is a sense in which claiming always to fail is comedy not tragedy. It releases us from the lie of success, frees us from the obligation to adopt its thin veneer, and allows us to do whatever it is we do for its own sake.”

My own suspicion is that Beckett was hinting at the glorious tragedy of our own self-delusion, in which we tell ourselves that we will eventually transform failure into success, and that the world really cares whether we do or not. We are not Steve Jobs but Harold Steptoe (and if you’re too young to get that allusion, you can thank me later for broadening your horizons), doomed forever to be making pathetic plans for betterment in a kind of frenzied desperation, forever glimpsing our cherished goal only to have it snatched from our grasp by the realities of our sad and miserable existence. And perhaps to realise that our only real hope of solace lies in accepting that Albert will always thwart our efforts, so that we might ask well celebrate failure and get drunk with the surly old sod.

But imagine trying to sell that in Silicon Valley.