This week I have mostly been working on all things Bragg and X-ray crystallography related. How you react to that news probably says a lot more about you and your educational background than it does the actual story I’m going to tell. I’m not talking about Billy or Melvin, or about any particular modern application of X-ray crystallography. No, I’m talking about William Henry and William Lawrence Bragg and their Nobel Prize winning work pioneering X-ray crystallography at Leeds 100 years ago.
(Image is from wikipedia)
This formula was worked out by this father and son team and it shows us that you can use X-rays to work out the structure of a material that has a crystalline structure – things like salt, diamond, DNA, to name but a few. That’s roughly how it works anyway. And the Braggs tried it out too, building their own equippment since there was nothing available that was quite what they needed at the time. Please don’t be put off by the equation, it really is only trigonometry if you look. No more daunting than 10 syllable word or some complicated spelling.
Anyway, how did this all come about, and is their story interesting to people who aren’t historians of science? Well, I think so, and this is why. The Bragg story begins in Adelaide, Australia. William Henry, the father in this story (I think this is why I like it, its all science and domesticity), had moved to Australia from England to become Professor of Physics. There he met and married Gwendoline Todd, daughter of Charles Todd, an astronomer and former employee of the Royal Observatory, Greenwich, and Alice Bell, after whom Alice Springs was named. Gwendoline had received a sound mathematical and scientific up bringing, and brought this to her new role as mother after the couple had three children. Actually, that last bit was a bit of a guess, based on her family background. Of course we don’t know anything about Gwendoline Todd, that research has yet to be done. They definitely had three children though. The university wasn’t terribly well equipped – lab work in universities was only beginning to become standard – and so William Henry ended up learning a fair amount of instrument making while he was there.
As the children grew up, Gwendoline, I’m guessing, would take care of their day to day education, while William Henry would try and involve them in his work whereever he could. My favourite Bragg story from this era tells of the day their eldest son Henry Lawrence, then aged 5 years old, fell off his tricyle and broke is arm. His father had just been reading about Rontegen’s discovery of X-rays and how they could go right through the body and produce an image of the bones inside. His son’s accident struck him as the perfect opportunity to try it out. No ethical issues about experimenting on family members for him, oh no. Luckily for all concern it worked, and the incident is now claimed as the first medical application of X-rays in Australia.
In 1908 William Henry was offered the job of Cavendish Professor of Physics at Leeds (a year after his friend Ernest Rutherford had arrived in Manchester) and decided the time had come to bring his family to England to stay. The University at the time was heavily involved in the local wool trade, with almost all departments funded by, producing work and skilled workers for, or in some other way involved in that industry. The physics department managed to stay a little way removed from all of this, it wasn’t obvious how physics might help that industry, and so Bragg was left alone to follow his own interests. He continued to work on X-rays and to correspond with his friends and colleagues around the world. His eldest son meanwhile, William Lawrence went off to Cambridge to study first mathematics, then natural science.
Then, on a family holiday in Cloughton, a village on the Yorkshire coast, just up from Scarbourgh, William Henry and William Lawrence read about some experiments by Max Laue at the University of Munich. Laue had discovered that X-rays could be scattered by travelling through crystals. What the Braggs did was to take this observation a step further and find a practical way of using this to work out the structure of crystals, that is the way the atoms and molecules were arranged in a crystal. William Lawrence started working on the mathematics as soon as he got back to Cambridge. His father meanwhile talked to the head mechanic Jenkinson in the physics workshop back in Leeds about building an X-ray spectrometer to try it out.
This all took place in 1912 and 1913. They tried out their mathematics and spectrometer on crystals of rock salt and gave a paper on their finds at the Royal Society on 21st June 1913. This was followed by more papers on more crystals (including one on the structure of diamond). Then in November 1915 William Henry and William Lawrence were jointly awarded the Nobel Prize for physics, making William Lawrence the youngest winner in history, a record he still holds to this day. The pair didn’t go to the ceremony though. Just two months earlier, in September 1915 William Lawrence’s younger brother Bob was killed in the Gallipoli landings. The family were still getting over the shock.
At a recent meeting about how to celebrate this anniversary we started to talk about “bringing the story up to date”. How could we make this story relevant, what was their legacy, how does their work continue to this day in Leeds? Well, it soon became clear that it was not so much a question of how to define impact as where to draw the line. X-ray crystallography is used in so many different disciplines. In Leeds, while the university was still very much attached to the textile trade, it found a use soon after Bragg in examining the structure of wool fibres. It is, according the university’s new Bragg website – www.leeds.ac.uk/Bragg100 – today ‘one of the most widely used analytical techniques in science and engineering and has been fundamental to the development of various scientific fields within industry, including microelectronics, pharmaceuticals, aerospace and power generation.’
But do we need all these justifications to find the story interesting? Should history only be about winners and legacies? Surely we shouldn’t have to invent linear story of progress and impact in order to get people interested in scientific characters from history. They didn’t have to with Richard III, so why should we with Bragg? Well, from the point of view of the University, there is of course a very good reason. It gives a way in for all the various science departments to get involved in our events and activities. It means they can talk about their current work but link it in to this anniversary and the university’s heritage. But I think the historical angle could still work as a stand alone story. Especially if we knew a bit more about the family, and about Gwendoline’s family, and about the work involved in bringing up a potential Nobel Prize winner and in creating and equipping a world class research lab almost from scratch. That to me is what’s facinating about this story, but then, I’m not sure in this instance that I qualify as the general public. Do you? What do you think?