This whole blog of mine was meant to be about interdisciplinary science. At least, when I started it up, 3 years ago next month, that was what I had in mind as my major theme. In fact, like so much of my life, it hasn’t panned out quite as envisaged. In the early days there were a number of posts on the topic; more recently practically none. So, time to redress that balance. I have been at a conference this week, organised under the auspices of the EPSRC-funded Network on the Physics of Life (I’m on its steering committee). Its aim is to start shaping the dialogue about what the UK Physics community can offer in solving biological problems. In part, acting as a network, its role is to bring researchers together to find innovative ways of moving the field – and it’s pretty broad – forward. In part it aims, through focussed workshops and discussion sessions, to identify major challenges where the tools (conceptual as well as experimental) of the physicist can usefully tackle important biological problems.
This week’s first plenary event focussed on The Living Cell and was a mixture of talks and discussion. The discussion amongst the attendees in break-out groups was targeted at identifying possible topics for future meetings. In particular we want to identify themes that bridge the different lengthscales relevant to ‘life’, so from within a single cell up to the multicellular and whole organism level. We also want to make sure we have plenty of biologists amongst our attendees to keep us on the straight and narrow when it comes to biology. To paraphrase what Viola Vogel (one of our keynote speakers) said, physicists need to learn enough biology to be able to ask relevant biological questions, not merely ones they can simplify enough to solve.
For a physicist to become fluent in biology – or the same in reverse – takes time and effort. I hope the time when physicists thought all problems could be solved by sufficient simplification (see this xkcd cartoon) are long past, but I wouldn’t be too sure. Biology and physics may differ very substantially in the way they see problems, and that is exactly why conversations between them can be so rewarding once the language barrier is overcome; this needs to include the translation of acronyms, but also must include getting to grips with words that appear to be the same but have different connotations and those that are utterly unfamiliar.
Nevertheless, even the most bilingual of biological physicists (or equally physical biologists) is probably only going to have knowledge associated with some small area. Perhaps they are expert in lipids and cell membranes, or molecular machines such as kinesin, or the extracellular matrix; but they are unlikely to be expert in all of them. Unfortunately collectively there are too many ‘or’s’ like this, so it is impossible for any one of us to be an expert in more than a small niche area. What we can do is try to look for connections, use the skills we have to ask the unexpected questions of our colleagues and see if approaches used in one field can helpfully be applied elsewhere. It is this last ‘philosophy’ that has led my Cambridge colleague Ben Simons, a theoretical physicist whose background lies in chaos theory, to develop completely new ways of thinking about stem cell differentiation thereby leading to a rethink in the (biological) stem cell community. In some ways his theories are incredibly simple, essentially equivalent to work from the nineteenth century on how surnames propagate or die out, but their application to stem cell colonies meant the overturning of received wisdom – if I understand this right!
To digress briefly, regular readers of this blog may know that Erasmus Darwin is one of my heroes. He was a polymath, a physician by day, an innovator and entrepreneur in his spare time with interests ranging from carriage axles to meteorology, as well as a well-known poet in his day. Thomas Young, he of Young’s slits and modulus, was another physician (rather less successful than Darwin) who managed to cover an enormous range of sciences including optics (physics) and the mechanism of vision (biology) as well as elasticity and who also had a hand in decoding the Rosetta Stone. Not for nothing was a recent biography of him by Andrew Robinson entitled ‘The Last Man who Knew Everything‘.
This epithet should be contrasted with the title of another physicist’s biography I’ve just finished reading: ‘The Man who Changed Everything‘ , a book by Basil Mahon about the Scottish physicist James Clerk Maxwell. Having read this I realise that as an undergraduate physicist his name had been liberally sprinkled over my courses without me really taking in that fact. The Maxwell-Boltzmann distribution of velocities in gases was a key memory from my first year courses. Of course at that point I also encountered Maxwell’s equations for electromagnetism as I struggled with the ideas of div, grad and curl from vector calculus. Maxwell relations – those equations linking differentials of thermodynamic functions – featured in the second year. Somewhere along the line I must have been introduced to that friendly, impish character of Maxwell’s demon, who sits next to small slits to try to mess up the second law of thermodynamics, as an early example of a gedanken experiment. I didn’t realise Maxwell also played a key part in developing dimensional analysis too, an approach that seems obvious now but was much more obscure to me at the start of my undergraduate life.
Maxwell had very broad interests and an ongoing area of experimentation throughout his life was in colour. To him we owe the idea that all spectral colours can be made up of red, green and blue (the RGB palette familiar from Photoshop for instance), unlike the way paint colours add, and he created ingenious ways to study the make-up of the whole spectral range of colours. Indeed he took the first colour photograph, using red, green and blue filters to superimpose images, although the fact that this worked turns out to have been fortuitous, at least according to this biography.
But was he genuinely interdisciplinary or merely a fantastically gifted physical scientist? And if not what is he doing featuring in this post (other than because I have a deep admiration for polymaths)? Like Young, his interests in image formation included an interest in the eye itself. He developed apparatus for studying the eye, an early ophthalmoscope (although not the very first which had been developed by Helmholtz a little before) and used it to study the yellow spot (macula lutea) which is an opaque area on the retina. Indeed his discovery of the RGB system arose from his interest in colour vision and how we perceive colours.
Maxwell of course was the first head of my own Cavendish Laboratory, the man who was instrumental in the design of the old buildings in the centre of Cambridge. His time there was cut short by his death at only 48 but during his life what a huge amount he managed to accomplish. He knew the importance of knowing what you do know and what you don’t; of having the tenacity to tease out the simple from the messy and complicated and to know who to turn to when information from outside one’s own area of expertise is required. These are all skills we should work at acquiring, all the more so if we aspire to move from our own discipline to work in another, facilitating working with others whose backgrounds may be very different from our own.