William Lawrence Bragg, 1890–1971

Lawrence Bragg, microdiffraction and X-ray lasers.

We trace the historical development of W. L. Bragg's `law' and the key experimental observation which made it possible using polychromatic radiation at a time when neither X-ray wavelengths nor cell constants were known. This led, through his phasing and solving large mineral structures (without use of a computer), to work on metals, proteins, bubble rafts and his X-ray microscope. The relation...

Differential Geometry of Gerbes Lawrence Breen and William Messing

0. Introduction 1 1. Torsors and associated gauge groups 5 2. Gerbes and their gauge stacks 7 3. Morita theory 12 4. The gauge stack as an inner form 13 5. Comparison with the explicit cocycles 20 6. Connections on torsors and groups 23 7. Connections on gerbes 32 8. Curving data and the higher Bianchi identity 40 9. Partially decomposed gerbes with connections 48 10. Fully decomposed gerbes wi...

On the structure of aragonite -- Lawrence Bragg revisited.

The structure of aragonite was first determined by Lawrence Bragg in 1924 in what is the now standard space-group setting Pnma (No. 62). Subsequent studies have all taken his structure as their starting points, despite Bragg's own stated doubts and some earlier etching studies which indicated that the underlying symmetry may really be polar. We have reinvestigated the structure and found that t...

Sir William Lawrence (1783-1867); a study of pre-Darwinian ideas on heredity and variation.

Lawrence Kruger