Wednesday, 5 September 2012

Brazil and Moseley, Mostly

The beach at Maresias
The view from the hotel
I have the pleasure of being at a conference in Brazil.  It's at a lovely location on the coast, by a nice beach, which is something of a surfers' haven.  I've never tried surfing, and I'm not about to start, at least not given the size of the waves here.  It's nice just being by the sea, though, and winter in Brazil is not a bad sort of climate to spend a few days in.  I attach an obligatory picture of the sea, taken a few steps from my hotel room.

As well as giving a talk, I've learnt about much of the nuclear physics research that goes on in Brazil, spanning experimental work, partly carried out at the São Paulo Pelletron, to theoretical stuff, to quite a lot of applied areas, like environmental radiation monitoring and cancer therapy.  All interesting stuff, but I just want to mention one interesting fact that I learned in a talk by Navin, a physicist working at GANIL in France, this morning.  He was talking about Moseley's Law, an empirical relation between the frequencies of X-rays emitted from atoms and the nuclear atomic number.  It did much to cement the Rutherford model of the atom in the earliest days of nuclear physics.  Moseley was British, and worked at Oxford and Manchester in the years preceeding the First World War.  If I remember rightly, there was a plaque dedicated to him outside of one of the lecture theatres in the Clarendon Lab at Oxford.

I already knew about Moseley's Law, but one thing that Navin mentioned in his talk was news to me.  I did know that Henry Moseley signed up to fight in World War One, and was killed by a sniper in Gallipoli.  The death of anyone is, of course, a personal tragedy to friends and family, but Moseley's death was also a loss to the physics community.  He was a first-class scientist, who would most likely have been considered very seriously for a Nobel prize in the years shortly after his death (they are never awarded posthumously).  What I didn't know was that, apparently, Moseley's death caused the British government to stop sending leading or promising scientists to the front line in wars.  I did not know that this was a policy and that it was caused by this single event.  I wonder if the rule still applies now and how they judge who is sufficiently good not to be conscripted (or even allowed to volunteer).