Pierre-Gilles de Gennes 1932-2007

I was sorry to hear that Pierre-Gilles de Gennes, the great French theoretical physicist, died a week ago last Friday, following a long struggle with cancer. De Gennes, who won the Nobel Prize for Physics in 1991, created much of our modern understanding of liquid crystals, colloids and polymers, essentially founding the field of soft condensed matter by recognising the common features of these soft systems characterised by interaction energies comparable to thermal energies and dominated by Brownian motion.

This obituary in Le Monde has a good account of his life and work. My first introduction to his work was at the very beginning of my PhD. When I asked my supervisor what I should do to begin my studies, he told me to go to the bookshop, buy a copy of de Gennes’s book Scaling Concepts in Polymer Physics, and come back when I had read it. I did this, and very good advice it turned out to be; it’s a book I still refer to. Soon after I had the chance of meeting the man himself , when he listened with absolute attention and politeness to what this insignificant graduate student had to say.

De Gennes was an erudite, deeply cultured and utterly charming man. One of his passions outside physics was art, and he used art history to illustrate how he saw the role of the theoretical physicist evolving in a time when computer simulations are becoming ever more powerful. Just as the invention of photography meant that artists no longer felt the obligation to strive for simple verisimilitude, and could seek to capture the essence of their subject in increasingly impressionistic and abstract ways, so the fact that systems of great complexity could now be simulated on a computer left theorists with the job of sketching a description of these systems in a way that puts insight and transparency ahead of perfect accuracy. As the attention of physicists turns more and more towards complex and difficult systems (including living things, the most difficult systems of all) this insistence on cutting through the thicket of detail to focus on the essentials becomes ever more important.

In praise of Vaclav Smil

In my efforts to educate myself about how new technologies might impact on our economy and society, the author from whom I’ve learnt the most is unquestionably Vaclav Smil. Smil is a Professor in the Department of Environment and Geography at the University of Manitoba, but his writings cover the whole sweep of the interaction of technology and society. What I appreciate about his books is their emphasis on rigorous quantification, their long historical perspective and global span (Smil is an expert on China, among many other things), and their grounding in the things that matter – how we get the food we eat and the energy that underlies our lifestyles.

My introduction to Smil’s work came when I needed a rapid introduction to energy economics. His 2003 book Energy at the Crossroads: global perspectives and uncertainties does this job in an admirably clear-headed and realistic way. It has a particularly sobering view of the poor record of energy forecasting in the past, and of the evolution of linkages between economic growth and output and energy inputs. Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production takes a historical view of the linkage between energy and food. Few people nowadays stop to think about the importance of artificial nitrogen fixation, powered by fossil fuels, in feeding the world. Yet it is clear that without artificial fertilizers more than half of the current population of the earth would not be alive today. We are effectively surviving by eating oil. This theme is developed in Feeding the World: A Challenge for the Twenty-First Century, which asks the fundamental question, just how many people could the world feed? After a period of plentiful and cheap food, at least in the West, we’ve forgotten about some of the more apocolyptic visions of mass famine. Yet the world food supply equation is probably more fragile than we’d like to think. This is likely to get worse, as climate change, water shortages, and environmental degradation puts pressure on yields, and increasing demand for biofuels increases demand for non-food uses of crops.

Many of these themes are brought together, with many other trends, in two of Smil’s most recent books, Creating the Twentieth Century: Technical Innovations of 1867-1914 and Their Lasting Impact and Transforming the Twentieth Century: Technical Innovations and Their Consequences . Taken together, these two volumes offer the best overview of how the world we live in now has developed that I know of. At one level, this is simply a narrative history of modern technology, albeit one that takes a holistic view of the way in which many different inventions come together to make important innovations possible. In this sense, it’s the story of accelerating change, in which one technological development facilitates another. But he is explicitly dismissive of those who are too quick to plot exponential curves and extrapolate from them. The title of his first book makes it clear that in Smil’s view, the true technological revolution took place in the last part of the 19th century, and what we have seen since then is largely the unfolding of the developments that were initiated in this great saltation. And he is by no means certain that the rapid change will continue, noting the degree to which it has been built on a massive, and probably unsustainable, growth in energy consumption. His agnostic outlook is summed up in the last chapter, where he asks:

“have the last six generations of great technical innovations and transformations merely been the beginning of a new extended era of unprecedented accomplishments and spreading and sustained affluence – or have they been a historically ephemeral aberration that does not have any realistic chance of continuing along the same, or a similar trajectory, for much longer?”

Ideologies and nanotechnology

There are many debates about nanotechnology; what it is, what it will make possible, and what its dangers might be. On one level these may seem to be very technical in nature. So a question about whether a Drexler style assembler is technically feasible can rapidly descend into details of surface chemistry, while issues about the possible toxicity of carbon nanotubes turn on the procedures for reliable toxicological screening. But it’s at least arguable that the focus on the technical obscures the real causes of the arguments, which are actually based on clashes of ideology. We supposedly live in a non-ideological age, so what are the ideological divisions that underly debates about nanotechnology? I suggest, for a start, these four ideological positions, each of which implies a very different attitude towards nanotechnology.

  • Transhuman. Transhumanists look forward to a time in which technology allows humanity to transcend its current physical and mental limits. Radical nanotechnologies are essential to the fulfillment of this vision, so the attitude of transhumanists to nanotechnology in its most radical, Drexlerian form, is that it is not only inevitable but morally mandated.
  • Transglobal. Those who accept the current neo-liberal, globalising consensus look to new technologies as a driver for further economic growth. Nanotechnology is expected to lead to changes which may be disruptive to individual business sectors, but which probably won’t fundamentally change global socio-economic systems.
  • Deep Green. To radical environmentalists, our current urban, industrial economic system is unsustainable. Technologies are regarded as in large measure responsible for the difficulties we are now in, and a return to more rural, post-industrial, locally based economies is regarded as not only desirable but inevitable. Nanotechnology is, like most new technologies, viewed with deep distrust, as very likely to lead to undesirable and possibly unintended consequences.
  • Bright Green. Another strand of environmentalists share with Deep Greens the conviction that the current socio-economic system is unsustainable, but are confident that new technology and imaginative design will make possible an urban culture with a high standard of living that is sustainable. These people look with enthusiasm to nanotechnology for new sustainable energy systems and decentralised, low waste manufacturing processes.

When one sees a debate about nanotechnology start to get heated, it’s perhaps worth asking what the ideological positions of the debaters are, and whether an apparently technical argument is actually a proxy for an ideological one.