Researchers Measure 3D Force in Matter at the Single-Particle Scale

What started as a question to the A-exam became a revolutionary discovery in the material science field. Neil Y.C. Lin — a graduate student from Cornell University pursuing a physics Ph.D. — was asked if it was possible to measure forces at the single particle scale, given that the current methods can only measure said forces at bulk scale (in groups) on his A-exam. A-exam is an exam where Ph.D. candidates must attempt to answer questions that not even the professors know the answers to. This question led Lin to work with Prof. Itai Cohen, physics, Prof. James Sethna, physics, Matthew Bierbaum grad and Prof. Peter Schall, physics, University of Amsterdam. After three years of research, this team of theorists, computer calibrators, and crystal specialists found their answer in SALSA — not the tasty dip, but Stress Assessment from Local Structure Anisotropy.