On Size and the RI Christmas Lecture

This year's RI Christmas Lecture was given by Mark Miodownik, Head of the Materials Research Group in the Natural and Mathematical Sciences School at King's College London.  Appropriately approachable in suit and trainers and a slightly hesitant speaking style, he did rather well I thought.  His topic was 'Size Matters' and he covered a lot of ground.

For example, he discussed the old question of why small animals can survive long falls and large ones can't (using crash test pets).  He did this quite well - but I wish he'd mentioned J.B.S Haldane's famous 1928 essay (On Being the Right Size):

You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes. For the resistance presented to movement by the air is proportional to the surface of the moving object. Divide an animal's length, breadth, and height each by ten; its weight is reduced to a thousandth, but its surface only a hundredth. So the resistance to falling in the case of the small animal is relatively ten times greater than the driving force.

OK, I suppose perhaps not quite right for his young audience - commendably brief but the Christmas Lecture requires more spectacle (the crash test pet dog did splash...). 

Anyway, Miodownik covered this, why larger animals are cumbersome (can't dance), the relative strengths of creatures (against there body weight), and so forth, before he moved on to strange materials and then to very large scale structures.  He gave three lectures (I seem to remember recent speakers giving four?  maybe that is a false memory).   The last lecture took us from how high a building might we be able to build one day, given the limitations of the Earth's surface as a base to start from, to the space elevator, by way of carbon nanotubes.  It ended with him on wires, high above his audience and a model of the earth, paying out model nanotube cable to get the elevator going.

There is a kind of convention whereby the Christmas Lecturer ends by exhorting the younger generation to discover new things and follow in the scientific and/or technological footsteps of their parents and predecessors... He did this bit especially well, I thought - moving from the moon landings of the 60s and 70s to the possibilities of the space elevator - if they can do it.

His delivery was hesitant, as I said, and there seemed to be a large number of strange diversions into different types of new material which at the time I thought didn't really aid his argument much, but in retrospect that was too critical of me.  The whole piece came together very well, and worked.  I ended up feeling quite inspired by the dangling man.

And it was back on the BBC where it belongs.