Building a better foam

I have a story on Nature’s blog about a nice new paper on ‘minimal foams’, which finally reports evidence for the Weaire-Phelan foam reported several years ago to be a more energetically favourable structure than Kelvin’s, postulated in 1887. Denis Weaire has written a nice (but goodness me, pricey) account of this so-called Kelvin Problem. And I get to show last year’s holiday snaps in Beijing…
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Physicists working at Trinity College in Dublin, Ireland, have finally made the perfect foam. Whereas most Dubliners might consider that to be the head of a pint of Guinness, Denis Weaire and his coworkers have a more sophisticated answer.

‘Perfect’ here means the lowest-energy configuration of packed bubbles of equal size. This is a compromise. Making a soap film costs energy proportional to the film’s surface area. But the many interlocking faces of an array of polyhedral bubbles in a foam also have be mechanically stable. The Belgian scientist J. A. P. Plateau calculated in the nineteenth century that three soaps films are mechanically stable when they meet at angles of 120o, whereas four films meet at the tetrahedral angle of about 109.5o.

So what bubble shape minimizes the total surface area while (more or less) satisfying Plateau’s rules? That’s essentially the same as asking what shape balloons, or any squashy spheres, will adopt when squeezed together. Scientists including the French zoologist Georges Buffon have pondered that, using lead shot and garden peas, for centuries. The Irish scientist Lord Kelvin thought he had the answer in 1887: the ‘perfect foam’ is one in which the cells are truncated octahedra, with eight hexagonal faces and six square ones – provided that the faces are a little curved to better fit Plateau’s rules.

Kelvin’s solution was thought to be optimal for a long time, but there was no formal proof. Then in 1994 Weaire and his colleague Robert Phelan found a better way. It wasn’t so elegant – the structure had a repeating unit of eight polyhedra, six of them with 14 faces and two with 12, all with hexagons and imperfect pentagons and again slight curved (see first pic above). This has 0.3 percent less surface area than Kelvin’s foam.

But does it really exist? The duo found no definitive evidence of their ideal foam in experiments (conducted with washing-up liquid). Now there is. The key was to find the right container. Normal containers have flat walls, which the Weaire-Phelan (WP) foam won’t sit comfortably against. But physicist Ruggero Gabbrielli from the University of Trento figured that a container with walls shaped to fit the WP foam might encourage it to form. He has collaborated with Weaire and his colleagues, along with mathematician Kenneth Brakke at Susquehanna University in Pennsylvania, to design and make one out of plastic.

When the researchers filled this container with equal sized bubbles, they found that the six layers of about 1500 bubbles were ordered into the WP structure (see second pic above). They describe their results in a paper to be published in the Philosophical Magazine Letters.

This isn’t actually the first time that the WP foam has been made. But the previous example was built by hand, one cell at a time, from girders and plastic sheets, to comprise the walls of the iconic Olympic Swimming Stadium in Beijing (see third pic above).

Christmas reading

John Whitfield’s new book about reputation, People Will Talk, is out, and I am, to be honest, envious – and I haven’t even read it yet. First, John has picked such a great and timely topic. And second, I know that he will have covered it brilliantly. Yes, this is a shameless plug for my pals, but I really want John’s book to get the attention it deserves, and not get lost among all the pre-Christmas celebrity memoirs.

And while I’m plugging, look out for the debut novel Random Walk by Alexandra Claire, published by Gomer. I’m only part of the way through, but enjoying it for much more profound reasons than the fact that it quotes from my Critical Mass at the beginning (and not just because I’m a Cymruphile either).

The sun and moon in Italy

Now that it’s happened, I can say that there’s definitely something uniquely challenging about having your fiction translated. The Sun and Moon Corrupted has become, in Italian, La Città del sole e della Luna (The City of the Sun and the Moon). I can live with that change, not least because I like the resonance with Tommaso Campanella’s visionary early seventeenth-century work The City of the Sun, which becomes somewhat apt. But how have the voices translated? In particular (this Italian illiterate wonders), how have they dealt with the eccentric English of Karl Neder and his fellow Eastern Europeans? How does one translate the Brixton riots and the Wapping news era – the whole oppressive gloom of the middle Thatcher years – to Italians?

Whatever the case, Edizioni Dedalo have done a nice job on the superficial level to which I am constrained: I like the faux-naif cover. I just hope there’s still enough disposable income in Italy for people to read it.

Surprise prize

The Royal Society Winton Prize for science books was awarded last night. I have written a piece on it for Prospect’s blog. Here it is for convenience.
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Part of the pleasure of the presentation of the Royal Society Winton Prize for Science Books on Thursday night was that it was happening at all. Having lost its corporate sponsor (Rhône-Poulenc, subsequently merged to Aventis) after 2006, the prize was nobly supported by the Royal Society alone for the past four years but looked increasingly in danger of folding. Now it has been rescued by the British investment firm Winton Capital Management, who have agreed to back it for five years. So popular science still has its Man Booker.

The winning title, Gavin Pretor-Pinney’s The Wavewatcher’s Companion (Bloomsbury), was a surprise. In both cover and content, it looks like a sequel to Pretor-Pinney’s previously successful The Cloudspotter’s Guide, but it won over the judges with what Richard Holmes, chair of the judging panel, called “old-fashioned charm and wit”. Like many of the best science books, it doesn’t at first seem to be about science at all, but is a celebration of the ubiquity of waves of all sorts, from sonar to football crowds.

‘Wit’ seems to have been a valuable feature. Holmes commented on how often humour was employed in the submitted books. That’s encouraging – not because science books have previously been dour, but because they have often had a tendency towards leaden adolescent humour of the “imagine finding that in your sandwich!” variety. This sort of thing wouldn’t have passed muster with the erudite Holmes, whose The Age of Wonder (2009 winner of the prize) was, among many other praiseworthy things, a model of the wry footnote.

But another issue bothered some of the attendees. As the six white male shortlisted authors sat on the stage, broadcaster Vivienne Parry asked “Where are all the girls?” (Tucked up in bed, one was tempted to reply, but you could see her point.) The (typically gender-balanced) judges confessed that this had been a serious concern, but one that they could do nothing about. It’s even worse when you look at the prize’s history: only one woman has ever won it (anthropologist Pat Shipman in 1997), and then as a co-author. Parry is herself one of the very few women to have been shortlisted.

A glib answer is that this just reflects the lack of women in science. But that isn’t the case for science journalism and publishing. It is mercifully free of the male-domination still evident in the lab: at least half of the editorial staff of Nature are women, and this is fairly representative. Plenty of female science writers and scientists have authored books. And the imbalance is all the more troubling when compared to the strong female showing in other non-fiction literary awards such as the Samuel Johnson. So “what’s that about?”, asked science journalist Ian Sample, also on the science book prize shortlist, in response to Parry’s question. No one seemed to know.

Identity crisis

This is not me, though I kind of wish it was.

Everyone (except, I am willing to bet, my daughters) has namesakes, but there’s genuine scope for confusion here, as I’ve just discovered. There’s also a young medical writer called Philip Ball. I think someone should book us all to talk on the same platform.

PS Funnily enough, I've just discovered that it goes further. This nice discussion of my appearances at the Edinburgh Book Festival claims to direct the reader to my "surprising" web site - which is probably even more of a surprise when, with a double "l" in my name, it in fact takes you here.

Who is human?

Back from two weeks in China, with some things to catch up on. I have a feature article on graphene in the latest issue of the BBC's science magazine Focus - not available online, sadly. And an article on pattern and shape in the glossy lifestyle & sports magazine POC - also not (yet) available on the web, but I'll put the piece on my website shortly. And here is a book review I did for the Observer on 7 October.
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What It Means to be Human:
Reflections from 1791 to the Present
Joanna Bourke
Virago, 2011
ISBN 978-1-84408-644-3

“Are women animals?”, asked a correspondent to the Times in 1872 who described herself only as “An Earnest Englishwoman.” Her point was not that women should be regarded as less than fully human, but that they already were – to such a degree that they would have more rights if they could at least be granted the same status as cats, dogs and horses. The law could be more punitive to a man who ill-treated his horse than to one who murdered his wife.

Inmates at Guantánamo Bay made precisely the same case. Noticing a dog in an air-conditioned kennel next to Camp X-Ray, a British detainee said to the guards “I want his rights” – only to be told “That dog is a member of the US army.” Clive Stafford Smith, representing the inmates, declared that “it would be a huge step for mankind of the judges gave our clients the same rights as the animals.”

As these cases illustrate, historian Joanna Bourke’s survey is not so much about the boundaries of humankind as about the way in which some humans have systematically denied full personhood to others, particularly women, children and other (generally non-European) races and cultures. She would have helped her argument by keeping that distinction more clear. When for example she remarks apropos of slavery that it questions “who is truly human and who is merely ‘property’”, only to follow with the suggestion that “the claim that some humans are property rather than true ‘persons’ is still rampant”, the confusion muddies the point.

Although the forms of denigration that Bourke considers are certainly ‘dehumanizing’, they don’t usually challenge biological or species identity. Rather, they erect hierarchies of human worth, development, and supposed intellectual and spiritual capacity. All the same, her well-made thesis is that this tendency has commonly pushed the oppressed group towards the realm of beasts, whether via the bird-like ‘twittering’ of women or the ‘simian’ countenance of African slaves.

It is an ugly spectacle to see with what insufferable smugness and pseudoscientific justification these judgements have been repeatedly made by white Western males. And of course it would be nonsense to pretend that we all know better now. Yet there is something a little paralysing about this detailed exposé of the obviously pernicious. It is not to belittle the evils of slavery, racism, female oppression and the Holocaust to say that they are, in themselves, scarcely news.

There is also a strong risk of presentism in all this: judging the past as if it were the present. While it is no response to protest that no one knew any better in those days (not least because plenty of women and slaves certainly did), one is left wondering how to contextualize Darwin’s references to “savages… on [a] par with Monkeys” and his chauvinistic hierarchy of races relative to, say, Thackeray’s or Carlyle’s hysterical aversion to African-Americans. It is surely an oversight that nothing is made of Darwin’s anti-slavery motivation in showing that humankind is truly one species, given how thoroughly this was recently documented by Adrian Desmond and James Moore.

The kind of exclusivity that Bourke explores is at least as old as slavery itself, which occasionally means that one feels the absence of the long view. The nastiness and bigotry on display here would be found in spades in the Middle Ages or ancient Greece, albeit differently nuanced. Bourke shows how fears of animalization in the use of animal tissue in medicine have remained more or less unchanged from Jenner’s cowpox vaccinations in 1796 to xenografts of animal organs today. But it seems a shame not to consider the same themes in Thomas Shadwell’s play The Virtuoso (1676), where he satirized the animal-to-human transfusion experiments of the Royal Society. And when one critic of vaccination worried that it might induce ladies to “receive the embraces of the bull”, there are significant echoes of the legendary coupling of Pasiphae and Minos’s beautiful bull to produce the monstrous Minotaur.

But within the scope that Bourke has set herself, she has found some extraordinary material, such as the rejuvenation experiments of Serge Voronoff in the 1920s. These involved placing slices of simian testicle inside a man’s scrotum under local anaesthetic. An analogous anti-aging procedure for women was harder to arrange, but in any event deemed less important (not everything stays the same, then). Women did, however, worry about receiving the advances of septuagenarians whose renewed sexual vigour was said to be “abnormal both in degree and character”.

No wonder it is an embarrassment to endocrinologists that this is how their field began, although I didn’t need to be told that twice in the same chapter. Such repetition is not the only evidence of some loose editing. Lapses into the gnomic wink-wink traits of literary theory are mercifully rare, but to define molecular biologist James Watson as a “leading Darwin scholar” is eccentric at best. Perhaps that’s part and parcel with the neglect of modern genomics, the most egregious omission in the book.

Yet if the narrative is patchy, it is more than a collection of historical curiosities. Bourke’s critique of the concept of human rights opens an important debate on a complacent ideal, while her cross-examination of animal welfare should give all parties pause for thought. And she is quite right to say that modern biomedical science genuinely does now complicate the definition of humanity in ways that we are ill equipped, ethically and philosophically, to confront.