Thursday, December 20, 2007

Wise words from the Vatican?
[I’m no fan of the pope. And what I don’t say below (because it would simply be cut out as irrelevant) is that his message for World Peace Day includes some typically hateful homophobic stuff in regard to families. AIDS-related contraception and stem-cell research are just two of the areas in which the papacy has put twisted dogma before human well-being. But I feel we should always be ready to give credit where it is due. And so here, in my latest Muse article for Nature News, I try to do so.]

When Cardinal Joseph Ratzinger became Pope Benedict XVI in 2005, many both inside and outside the Christian world feared that the Catholic church was set on a course of hardline conservatism. But in two recent addresses, Benedict XVI shows intriguing signs that he is keen to engage with the technological age, and that he has in some ways a surprisingly thoughtful position on the dialogue between faith and reason.

In his second Encyclical Letter, released on 30 November, the pope tackles the question of how Christian thought should respond to technological change. And in a message for World Peace Day on 1 January 2008, he considers the immense challenges posed by climate change.

Let’s take the latter first, since it is in some ways more straightforward. Benedict XVI’s comments on the environment have already been interpreted in some quarters as “a surprise attack on climate change prophets of doom” who are motivated by “dubious ideology.” According to the British newspaper the Daily Mail, the pope “suggested that fears over man-made emissions melting the ice caps and causing a wave of unprecedented disasters were nothing more than scare-mongering.”

Now, non-British readers may not be aware that the Daily Mail is itself a stalwart bastion of “dubious ideology”, but this claim plumbs new depths even by the newspaper’s impressive standards of distortion and fabrication. Here’s what the pope actually said: “Humanity today is rightly concerned about the ecological balance of tomorrow. It is important for assessments in this regard to be carried out prudently, in dialogue with experts and people of wisdom, uninhibited by ideological pressure to draw hasty conclusions, and above all with the aim of reaching agreement on a model of sustainable development capable of ensuring the well-being of all while respecting environmental balances.”

Hands up those who disagree with this proposition. I thought not. When you consider that the idea that human activities might affect climate has been around for over a century, and the possibility that this might now be occurring has received serious study for more than two decades – during which time the climate science community has resolutely resisted pressing any alarm buttons until they could draw as informed a conclusion as possible – you might just begin to doubt it is they, and their current consensus that human-induced climate change seems real, who are in the pope’s sights when he talks of “hasty conclusions”. Might the charge be levelled, on the contrary, at those who pounce on every new suggestion that there are other factors in climate, such as solar fluctuations, as evidence of a global scientific conspiracy to pin the blame on humanity? I leave you to judge.

The pope’s statement is simply the one that any reasonable person would make. He calls for investment in “sufficient resources in the search for alternative sources of energy and for greater energy efficiency”, for technologically advanced countries to “reassess the high levels of consumption due to the present model of development”, and for humankind not to “selfishly consider nature to be at the complete disposal of our own interests.” Doesn’t that just sound a little like the environmentalists whom the pope is said by some to be lambasting? Admittedly, one might ask whether the Judaeo-Christian notion of human stewardship of the earth has contributed to our current sense of entitlement over its resources; but that’s another debate.

So far, then, good on Benedict XVI. And there’s more: “One must acknowledge with regret the growing number of states engaged in the arms race: even some developing nations allot a significant proportion of their scant domestic product to the purchase of weapons. The responsibility for this baneful commerce is not limited: the countries of the industrially developed world profit immensely from the sale of arms… it is truly necessary for all persons of good will to come together to reach concrete agreements aimed at an effective demilitarization, especially in the area of nuclear arms.” Goodness me, it’s almost enough to make me consider going to Christmas Mass.

The Encyclical Letter, meanwhile (entitled “On Christian Hope”), bites into some more meaty and difficult pies. On one level, its message might sound rather prosaic, however valid: science cannot provide society with a moral compass. The pope is particularly critical of Francis Bacon’s vision of a technological utopia: he and his followers “were wrong to believe that man would be redeemed through science.” Even committed technophiles ought to find that unobjectionable.

Without doubt, Benedict XVI says, progress (for which we might here read science) “offers new possibilities for good, but it also opens up appalling possibilities for evil.” He cites social philosopher Theodor Adorno’s remark that one view of ‘progress’ leads us from the sling to the atom bomb.

More generally, the pope argues that there can be no ready-made prescription for utopia: “Anyone who promises the better world that is guaranteed to last for ever is making a false promise.” Of course, one can see what is coming next: “it is not science that redeems man: man is redeemed by love” – which the pope believes may come only through faith in God. Only with that last step, however, does he enter into his own closed system of reference, in which our own moral lack can be filled only from a divine source.

More interesting is the accompanying remark that “in the field of ethical awareness and moral decision-making… decisions can never simply be made for us in advance by others… in fundamental decisions, every person and every generation is a new beginning.” Now, like most spiritual statements this one is open to interpretation, but surely one way of reading it is to conclude that, when technologies such as stem cell science throw up new ethical questions, we won’t find the answers already written down in any book. The papacy has not been noted for its enlightened attitude to that particular issue, but we might draw a small bit of encouragement from the suggestion that such developments require fresh thinking rather than a knee-jerk response based on outmoded dogma.

Most surprising of all (though I don’t claim to have my finger on the pulse of theological fashion) is the pope’s apparent assertion that the ‘eternal life’ promised biblically is not to be taken literally. He seems concerned, and with good reason, that many people now regard this as a threat rather than a promise: “do we really want this – to live eternally?” he asks. In this regard, Benedict XVI seems to possess rather more wisdom than the rich people who look forward to resurrection of their frozen heads. ‘Eternal life’, he says, is merely a metaphor for an authentic and happy life lived on earth.

True, this then makes no acknowledgement of how badly generations of earlier churchmen have misled their flock. And it seems strange that a pope who believes this interpretation can at the same time feel so evidently fondly towards St Paul and St Augustine, who between them made earthly life a deservedly miserable existence endured by sinners, and towards the Cistercian leader Bernard of Clairvaux, who in consequence pronounced that “We are wounded as soon as we come into this world, while we live in it, and when we leave it; from the soles of our feet to the top of our heads, nothing is healthy in us.”

Perhaps this is one of the many subtle points of theology I don’t understand. All the same, the suggestion that we’d better look for our happiness on an earth managed responsibly, rather than deferring it to some heavenly eternity, gives me a little hope that faith and reason are not set on inevitably divergent paths.

Friday, December 14, 2007

Can Aladdin’s carpet fly?
[Here’s a seasonal news story I just wrote for Nature, which will appear (in edited form) in the last issue of the year. I gather, incidentally, that the original text of the ‘Arabian Nights’ doesn’t specify that the carpet flies as such, but only that anyone who sits on it is transported instantly to other lands.]

A team of scientists in the US and France has the perfect offering for the pantomime season: instructions for making a flying carpet.

The magical device may owe more to Walt Disney than to The Arabian Nights, but it is not pure fantasy, according to Lakshminarayanan Mahadevan of Harvard University, Mederic Argentina of the University of Nice, and Jan Skotheim of the Rockefeller University in New York. They have studied the aerodynamics of a flexible, rippling sheet moving through a fluid, and find that it should be possible to make one that will stay aloft in air, propelled by actively powered undulations much as a marine ray swims through water [1].

No such carpet is going to ferry humans around, though. The researchers say that, to stay afloat in air, a sheet would need to be typically about 10 cm long, 0.1 mm thick, and vibrate at about 10 Hz with an amplitude of about 0.25 mm. Making a heavier carpet ‘fly’ is not absolutely forbidden by physics, but it would require such a powerful engine to drive vibrations that the researchers say “our computations and scaling laws suggest it will remain in the magical, mystical and virtual realm.”

The key to a magic carpet is to create uplift as the ripples push against the viscous fluid. If the sheet is close to a horizontal surface, like a piece of foil settling down onto the floor, then such movements can create a high pressure in the gap between the sheet and the floor. “As waves propagate along the flexible foil, they generate a fluid flow that leads to a pressure that lifts the foil, roughly balancing its weight”, Mahadevan explains.

But as well as lifting it, ripples can drive the foil forward – as any respectable magic carpet would require. “If the waves propagate from one edge”, says Mahadevan, “this causes the foil to tilt ever so slightly and then move in one direction, towards the edge that is slightly higher. Fluid is then squeezed from this end to the other, causing the sheet to progress like a submarine ray.”

To generate a big thrust and thus a high speed, the carpet has to undulate in big ripples, comparable to the carpet's total size. This makes for a very bumpy ride. ”If you want a smooth ride, you can generate a lot of small ripples”, says Mahadevan. “But you’ll be slower.” He points out that this is not so different from any other mode of transport, where speed tends to induce bumpiness while moving more smoothly means moving slower.

"It's cute, it's charming", says physicist Tom Witten at the University of Chicago. He adds that the result is not very surprising, but says "the main interest is that someone would think to pose this problem."

Could artificial flying mini-carpets really be made? Spontaneous undulating motions have already been demonstrated in ‘smart’ polymers suspended in fluids, which can be made to swell or shrink in response to external signals. In September, a team also at Harvard University described flexible sheets of plastic coated with cultured rat muscle cells that flex in response to electrical signals and could exhibit swimming movements [2]. “In air, it should be possible to make moving sheets – a kind of micro hovercraft – with very light materials, or with very powerful engines”, says Mahadevan.

Mahadevan has developed something of a speciality in looking for unusual effects from everyday physics – his previous papers have included a study of the ‘Cheerios effect’, where small floating rings (like the breakfast cereal) stick together through surface tension, and an analysis of the sawtooth shape made by ripping open envelopes with a finger.

“I think the most interesting questions are the ones that everyone has wondered about, usually idly”, he says. “I think that is what it means to be an applied mathematician – it is our responsibility to build mathematical tools and models to help explain and rationalize what we all see.”


1. Argentina, M. et al., Phys. Rev. Lett. 99, 224503 (2007).
2. Feinberg, A. W. et al., Science 317, 1366-1370 (2007).

Thursday, December 13, 2007

Surfers and stem cells
[This is the pre-edited version of my Lab Report column for the January issue of Prospect.]

Just when you thought that the Dancing Wu Li Masters and the Tao of Physics had finally been left in the 1970s, along comes a surfer living on the Hawaiian island of Maui who claims to have a simple theory of everything which shows that the universe is an ‘exceptionally beautiful shape’. Garrett Lisi has a physics PhD but no university affiliation, and lists his three most important things as physics, love and surfing – “and no, those aren’t in order.”

But Lisi is no semi-mystic drawing charming but ultimately unedifying analogies. He is being taken seriously by the theoretical physics community, and has been invited to the high-powered Perimeter Institute in Waterloo, Canada, where leading physicist Lee Smolin has called his work “fabulous.”

One thing rather fabulous is that it is almost comprehensible, at least by the standards of modern fundamental physics. Lisi himself admits that, in comparison to string theory, the main contender for a theory of everything, he uses only “baby mathematics.” That’s not to say it’s easy, though.

A theory of everything must unify the theory of general relativity, which describes gravity and the structure of spacetime on large scales, with quantum theory, which describes how fundamental particles behave at the subatomic scale. To put it another way, gravity must be mixed into the so-called Standard Model of particle physics, which explains the interactions between all known fundamental particles – quarks, electrons, photons and so forth.

Physicists typically attempt unification by using symmetry. To put it crudely, suppose there are two particles that look the same except that they spin in opposite directions. These can be ‘unified’ into a single particle by appreciating that they can be interconverted by reflection in a mirror – a symmetry operation.

The idea is that the proliferation of particles and forces in today’s universe happened in a series of ‘symmetry-breaking’ steps, just as lowering a square’s symmetry to rectangular creates two distinct pairs of sides from four identical ones. This is already known to be true of some forces and particles, but not all of them.

Lisi claims that the primordial symmetry is a pattern called E8, known to mathematicians for over a century but fully understood only recently; it is rather like a multi-dimensional polyhedron with 248 ‘corners’. He has shown that all the known particles, plus descriptions of gravity, can be mapped onto the corners of E8. So a bit of it looks like the Standard Model, while a bit looks like gravity and spacetime. Twenty of the ‘corners’ remain empty, corresponding to hypothetical particles not yet known: the E8 model thus predicts their existence. It’s rather like the way nineteenth-century chemists found a pattern that brought coherence and order to the chemical elements – the periodic table – while noting that it had gaps, predicting elements that were later found.

Is E8 really the answer to everything? Physicists are reserving judgement, for Lisi’s paper, which is not yet peer-reviewed or published, is just a sketch – not a theory, and barely even a model. Mathematical physicist Peter Woit is unsure about the whole approach, saying that playing with symmetry just defers the question of what breaks it to make the world we know. But the trick worked before in the 1950s, when Murray Gell-Mann predicted a new particle by mapping a group of known ones onto a symmetry group called SU(3).

Lisi’s surfer-dude persona is fun, but so what, really? The real point is that his suggestion invigorates a field that, wandering in the thickets of string theory, sorely needs it.


Stem-cell researchers in Shoukhrat Mitalipov’s team at the Oregon Health and Science University might be forgiven a little chagrin. No sooner had they reported the breakthrough that has eluded the field for years than they were trumped by two reports seeming to offer an even more attractive way of making human stem cells. Having sung the praises of Mitalipov’s achievement, Ian Wilmut, the University of Edinburgh cloning pioneer who created Dolly the sheep, announced that he was ditching their approach in favour of the new one.

Stem cells are the all-purpose cells present in the very early stages of embryo growth that can develop into just about any type of specialized tissue cells. The ‘traditional’ strategy for making them with DNA matched to the eventual recipient involves stripping the genetic material from an unfertilized egg and replacing it with donor DNA, and then prompting the egg to grow into a blastocyst, the initial stage of an embryo, from which stem cells can be extracted. This is called somatic cell nuclear transfer (SCNT), and is the method used in animal cloning. It works for sheep, dogs and mice, but there had previously been no success for humans or other primates.

On 14 November last year, Mitalipov and colleagues reported stem cells made by SCNT from rhesus macaques that could develop into other cell types. But a week later, teams based at the universities of Kyoto and Wisconsin-Madison independently reported the creation of human stem cells from ordinary skin cells, by treating them with proteins that reprogrammed them. In effect, the proteins switch the gene circuits from a ‘skin cell’ to a ‘stem cell’ setting. This reversal of normal developmental pathways is extraordinary.

The two teams used different cocktails of proteins to do the reprogramming – the Wisconsin team manage to avoid an agent that carries a cancer risk – showing that there is some scope for optimising the mix. Best of all, the method avoids the creation and destruction of embryos that has dogged the ethics of stem-cell research. But Mitalipov insists that starting with eggs is still best, and he has now started collaborating with a team in Newcastle licensed to work with human embryos. After years of frustrating effort, suddenly all options seem open.

Wednesday, December 12, 2007

Money for old rope

… except without the money. At no extra work to myself, I appear in a couple of recent books:
The Public Image of Chemistry, eds J. Schummer, B. Bensaude-Vincent & B. Van Tiggelen (World Scientific, 2007). This is a kind of proceedings volume of a conference of (almost) the same name in 2004, supplemented by contributions from a session at the 5th International Conference on the History of Chemistry in 2005. There’s lots of interesting stuff in it. It contains my paper ‘Chemistry and Power in Recent American Fiction’, which was published previously in the journal Hyle.
Futures from Nature, edited by my friend Henry Gee and published by Tor in January 2008. This is a collection of 100 of the short sci-fi stories published in Nature in recent years, and includes a contribution (I won’t say a short story, more of a pastiche) by one Theo von Hohenheim, who sounds vaguely familiar. Buy it here.

And while I’m at it, I recorded today a review of the year in science for the BBC World Service’s Science in Action. Don’t know when it is being broadcast… but before the year is out, clearly.

And while I'm at it at it, I have a piece in the latest issue of Seed on why RNA is the new DNA...

Sunday, December 09, 2007

We’re only after your money

There is a very sour little piece in this Saturday’s Guardian from Wendy Cope on copyright. I should say first of all that I must acknowledge a few items:
1. Cope is right to say that a poem is much more likely to get copied (either digitally or on paper) and downloaded than an entire book – in that sense, poets are especially vulnerable to copyright violations.
2. It’s mostly damned hard making a living as a writer, and perhaps especially so as a poet, so some sensitivity to potential earnings lost seems reasonable.

But it seems rather sad to see a writer of any sort so bitterly possessive about their words. To read Cope’s piece, one might imagine that she sits scribbling away resentfully, thinking each time she finishes a poem, ‘Now, get out there and earn your keep, you little sod.’ Now, to be honest, my rather limited experience of Cope’s work tallies rather well with the notion that bitterness is one of her prime motivations, but this piece seemed so jealous of every last penny potentially denied her that one wonders why she doesn’t just throw in the towel and become a plumber. Indeed, it seems to me that she doesn’t even truly understand why people read or buy poetry. Why, if anyone genuinely loved her poems, would they be content to download a few from the web and, and then – well, then what? File the printouts? Poetry lovers must be among the most bookish people in the world – they surely relish having the books on their shelves, rather than just scanning their eyes briefly over a piece of downloaded text and then binning it.

‘You want to read my poems? Then buy the book’, is Cope’s crabby refrain. Does she pull her volumes off the shelves of public libraries, I wonder? What is particularly dispiriting about this little rant is that it gives no sense of writing being about wanting to share with people ideas, images, thoughts and stories – and recognizing that this will never happen solely through the medium of books sold – but that it is instead about creating ‘word product’ that you buggers must pay for.

No source of income is too minor or incidental that its possible loss is not begrudged. Other people reading your poems at festivals is no good, because you might not get your little commission for it. (You get paid just for standing up and reading out old words? What the hell are you complaining about?) Another thing I find odd, although perhaps it just shows that things work differently in the poetry world, is that Cope is so covetous of every last book sale because of its financial rewards. In non-fiction at least, if you’re the kind of writer who gets a substantial part of your income from royalties, as opposed to pocketing a modest advance that might with great luck be paid off in ten years’ time, then you must be selling so many books that you shouldn’t need the supplement of £1.20 for a book sale that comes from someone’s refusal to copy one of your poems and give it to friend.

But what caps it all – and indeed reveals the pathology of Cope’s obsession – is her anger and regret that all those possible royalties are going to be lost when you’re dead. “I sometimes feel a bit annoyed by the prospect of people making money out of my poems when I’m too dead to spend it”, she moans. Well personally, Wendy, if someone keeps my words alive when I’m not, I’ll be over the bloody moon, and I don’t give a damn what they make from doing so.

Thursday, December 06, 2007

Beyond recycling
[This is my Materials Witness column for the January 2008 issue of Nature Materials.]

It is surely ironic that global warming and environmental degradation now pose serious risks at a time when industry and technology are cleaner than at any other stage of the Industrial Revolution. Admittedly, that may not be globally true, but in principle we can manufacture products and generate energy more efficiently and with less pollution than ever before. So why the problem?

Partly, the answer is obvious: cleaner technologies struggle to keep pace with increased industrial activity as populations and economies grow. And green methodologies are typically costly, so aren’t universally available. But the equation is still more complex than that. For example, cars can be more fuel-efficient, less polluting and cheaper. But consumers who save money on fuel tend to spend it elsewhere: they drive more, say, or they spend it on holiday air flights. And cheap cars mean more cars. There is an ‘environmental rebound effect’ to such savings, counteracting the gains.

This is just one way in which ‘green’ manufacturing – using fewer materials and environmentally friendly processing, recycling wastes, and making products themselves recyclable or biodegradable – may fall short of its goal of making the world cleaner. All of these things are surely valuable, indeed essential, in making economic growth sustainable. But the problem goes beyond how things are made, to the issue of how they are used. We need to look not just at production, but at consumption.

One of the initiatives here is the so-called Product-Service System (PSS): a combination of product design and manufacture with the supply of related consumer services that has the potential to give consumers greater utility while reducing the ecological footprint. That might sound like marketing jargon, but it’s a tangible concept of proven value, enacted for example in formalized car-sharing schemes, leasing of temporary furnished office space, biological pest management services, and polystyrene recycling. It’s not mere philanthropy either: there’s a profit incentive too.

One of the key benefits of a PSS approach is that it might offer a way of simply making less stuff. You don’t need to be an eco-warrior to be shocked at the senseless excesses of current manufacturing. A splendid example of an alternative model is offered by a team in Sweden, who have outlined plans for a baby-pram leasing and remanufacturing scheme (O. Mont et al., J. Cleaner Prod. 14, 1509; 2006). Since baby prams generally last for much longer than they are needed (per child), who not lease one instead of buying it? If the infrastructure exists for repairing minor wear and tear, every customer gets an ‘as new’ product, and no prams end up on the waste tip in a near-pristine state.

Developing countries are often adept at informal schemes like this already: little gets thrown away there. But if implemented all the way from the product design stage, it is much more than recycling. What remains is to break our current cult of ‘product ownership’. Prams seem as good a place to start as any.