Defect dynamics revealed
Vassilis Pontikis · Physics World · 1990
Defining the protocol of an imaginary experiment and exploring the expected results theoretically is a standard methodology used by physicists. There is a multitude of such theoretical schemes which have become famous in classical or quantum mechanics and thermodynamics. The belief that computers can help in 'realising' such thought experiments is not new either, but originated with Von Neumann and Ulam in the 1940s. Fermi, Pasta and Ulam then used one of the first available digital computers to perform 'experiments' designed to study the behaviour of a system of particles interacting through weakly nonlinear interactions. Their early results were striking – to achieve equipartition this particular system showed a behaviour that could not be modelled using conventional statistical mechanics. In the past three decades spectacular advances have been made in the technology of computers and their application in numerical physics and materials science has become more and more intensive. One particular example that has proved fruitful in bridging these two disciplines is the study of mass transport in crystalline solids.