Book Reviews: The gentle pioneer
P.P. Ewald and his Dynamical Theory of X-ray Diffraction . Edited by D.W.J. Cruickshank, H.J. Juretschke & N. Kato. International Union of Crystallography, Oxford University Press, 1992. Pp. x+161, £40.00. ISBN 0-19-855379-X Paul Ewald, who died in 1985 at the age of 97, was one of the greats of modern science. Born in Berlin into a comfortable middle-class academic family, he developed a passion for mathematical physics. When Sommerfeld presented him with a list of possible topics for his Doctoral Thesis he chose one related to crystal optics. This work, presented in 1912, could be applied to the behaviour of X-rays in crystals and it is suggested that it was a conversation between von Laue and Ewald early in 1912 that gave von Laue the idea for his famous experimental demonstration of X-ray diffraction.