Abstract Photograph of Alan Lindsay Mackay. Alan Mackay, a crystallographer who challenged conventional ideas of crystallography, will probably be mainly remembered for his prediction of quasi-crystals. Joining Bernal's Birkbeck laboratory soon after World War II, when crystallography was in its early days, he made significant contributions to the field's development. In the 1960s he began to challenge the dominance of the lattice in classical crystallography. Arguing alternatively for the importance of local interactions led to the eponymous Mackay icosahedron that made a major impact on particle, cluster and intermetallics research. He solved the problem of non-periodically filling three-dimensional space with entities possessing five-fold symmetry, work that led to him predicting the occurrence of quasi-crystals, the experimental discoverer of which was awarded the Nobel Prize in chemistry. Pioneering contributions he made to generalizing crystallography included alternative ways of looking at structures based on curved two-dimensional surfaces, an approach that has wider applications outside science. Speaking, reading and writing in several languages, he travelled widely, becoming an expert in Russian and Eastern science, and developed collaborations throughout the globe—his home welcomed a frequent stream of scientific visitors who always found a warm welcome. He had strong views on the nature of science and on the role of science in society, concerned that science should be making the world a better place. Although some of his achievements were not properly recognized, he considered himself privileged to have taken part in what he called the Republic of Science—and he had a great, and often mischievous, sense of humour.
John L. Finney (Wed,) studied this question.