the N-extended massive superparticle action in 4D has 2N-extended supersymmetry. The generic action for an N-extended superparticle in D-dimensional Minkowski spacetime was also shown to have `hidden' supersymmetries (related by `dualities' to the manifest supersymmetries) such that the full supersymmetry

pared our minds for Einstein's relativity, though it remained for Einstein's former mathematics professor Hermann Minkowski to com- plete the task. Minkowski was a brilliant mathematician, eventually holding a chair at the University of Gottingen. But in Zurich, where he was one of Einstein's professors,