Alan Lindsay Mackay

Who is Alan Lindsay Mackay?

Alan Lindsay Mackay FRS is a British crystallographer, born in Wolverhampton on 6 September 1926. He spent his scientific career at Birkbeck College, founded by George Birkbeck, one of the Colleges of the University of London, where he was immersed in a liberal scientific atmosphere under the leadership of John Desmond Bernal. He became a Fellow of the Royal Society on 17 March 1988 and a Fellow of Birkbeck College on 2 March 2002. He is also a Fellow of the Mexican Academy of Sciences. Mackay has made important scientific contributions related to the structure of materials: In 1962 he published a manuscript that showed how to pack atoms in an icosahedral fashion; a first step towards five-fold symmetry in materials science. These arrangements are now called Mackay icosahedra. He is a pioneer in the introduction of five-fold symmetry in materials and in 1981 predicted quasicrystals in a paper entitled "De Nive Quinquangula" in which he used a Penrose tiling in two and three dimensions to predict a new kind of ordered structures not allowed by traditional crystallography. In a later manuscript, in 1982, he took the optical Fourier transform of a 2-D Penrose tiling decorated with atoms, obtaining a pattern with sharp spots and five-fold symmetry. This brought the possibility of identifying quasiperiodic order in a material through diffraction. Quasicrystals with icosahedral symmetry were found by Dan Shechtman and co-workers in 1984. For his contributions to quasicrystals in 2010 Mackay was awarded the Buckley Prize, of the American Physical Society, with Dov Levine and Paul Steinhardt. The Nobel Prize in Chemistry was awarded in 2011 to Dan Shechtman for the discovery of quasicrystals.