The place of soft matter in undergraduate physics courses

In 2005, the UK's national funding agency for the physical sciences, the ESPRC, commissioned an international review of research in physics in the country's universities.¹ Among the comments the panel made was the remark “it is the perception of the Panel that there are quite a few physics departments where students get little, if any, exposure to modern soft matter physics. This is regrettable, because soft matter physics has deep links with many other areas of science, whilst the theoretical concepts and experimental techniques of this field are of direct relevance for biophysics. In addition, soft matter physics has many industrial applications”. I completely agree with these sentiments. I am pleased to say, though, that students in the two departments that I have taught physics in – in the Universities of Cambridge and Sheffield – are not disadvantaged in this way. I was able to use the experience of teaching soft matter physics to undergraduates in these two universities, and the wisdom and advice I received from my colleagues, in writing the textbook Soft Condensed Matter.²

From the many possible motivations for teaching physics students about soft matter, I would pick out three key ones. Firstly soft matter physics offers some particularly concrete realisations of statistical mechanics. Statistical mechanics is, of course, one of the pillars of modern physics, yet to many students it seems dry, formal and difficult to grasp. In soft matter physics we see easily visualized applications of key concepts of statistical mechanics, such as the effect of entropy, phase transitions, mean field theories, and the importance of fluctuations. Brownian motion is a central theme, and an elementary treatment of transport quantities like viscosity, diffusion and viscoelasticity leads to simple introductions to powerful concepts such as fluctuation–dissipation theorems. My own preference in teaching the statistical mechanics relevant to soft matter physics is to emphasise the concrete aspects at the expense of formal elegance; these topics lend themselves well to this approach.

Secondly, there is a relevance and immediacy to the applications of soft matter physics to everyday life and modern technologies. A physicist should be able to give a simple answer to a question such as, what makes a solid solid, a liquid liquid and a glass neither one nor the other? Understanding intermediate states of order, such as liquid crystals, gives an appreciation of ubiquitous technologies such as liquid crystal displays. Closer to home, everyday experiences with paint, glue and all sorts of cooking operations make the peculiarities of complex fluids very familiar.

To me, it is the third reason that is perhaps the most fundamentally important – which is that soft matter physics gives the most natural route into appreciating the field of biological physics. Achieving a proper, physical and mechanistic understanding of how living things work remains one of the most fascinating and important uncompleted tasks of physics today, and it is soft matter physics that will provide the tools for achieving this understanding through powerful concepts such as self-assembly and conformational change.

It can seem that the pedagogy of physics changes rather slowly; certainly I don't see many fundamental differences between the content of the physics degree I did thirty years ago and what is taught today. One should not demand novelty for novelty's sake, but where a relatively new area of the subject offers pedagogic value, technical relevance and connections to important unsolved scientific questions, today's students should have the chance to learn about it. Soft Condensed Matter is unquestionably such an area.

Richard Jones, University of Sheffield

References

1. http://www.epsrc.ac.uk/SiteCollectionDocuments/Publications/reports/PhysicsInternationalReview.pdf, accessed 26 November 2012.
2. R. A. L. Jones, Soft Condensed Matter, Oxford University Press, Oxford, 2002.

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Footnote

† This article is part of a collection of editorials on Soft Matter Education.

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