The sheer beauty of crystals has fascinated and puzzled people for centuries, but it is only in the last 300 or so years that they have been studied scientifically.
Prior to 1912, much of what was known about what crystals were and what they were made of was conjecture based on little more observation than of their external forms.
Various scientists, for example, Kepler, Hooke and several others developed theories that suggested some sort of repeating elements as being the necessary requirement to make a crystal. In the 19th century, in particular, ideas about crystal symmetry came to the fore and this was used to classify different types of crystal.
However, in early 1912, Laue, Friedrich and Knipping, working in Muenich, were able to show that x-rays could be diffracted by crystals, the main aim of this work being to demonstrate that X-rays consisted of waves rather than particles.
However, Laue made a number of incorrect assumptions about the results and it was William Lawrence Bragg, at the young age of 22, who showed how Laue’s experiments could be interpreted in a memorable publication of November 11 1912, just over one hundred years ago! In particular he was able to determine the crystal structure of zinc sulphide, and thus he heralded in the modern subject of X-ray crystallography.
He carried on working together with his father William Henry Bragg publishing a series of important papers in 1913-1914, interrupted subsequently by the First World War.
Laue was awarded the Nobel Prize for Physics in 1914, and both father and son Bragg shared the Nobel Prize in 1915.
The younger Bragg still remains the youngest Nobel Prize winner ever. The two Braggs continued to make important scientific contributions, and their work has led to in excess of 23 Nobel prizes.
In this talk, I shall discuss some of the ideas prior to Bragg’s discovery and then explain how the Braggs have influenced science today and will certainly continue to do in the future.