CHAPTER 16: Quantum Mechanics Brings Uncertainty to the Atom: de Broglie, Schrödinger, Heisenberg, Dirac and Born (France, Switzerland, England, Austria, and Germany)

In 1924, Prince Louis-Victor de Broglie proposed the “wave-particle duality of matter”, after which Erwin Schrödinger treated electrons in atoms as confined waves that set up certain allowed wave patterns with corresponding energies described by “quantum numbers”. His wave equation, one of the most important in atomic history, is prominently inscribed above his grave in the picturesque Austrian town of Alpbach and below his bust at the Arcades of the University of Vienna. The story of the “erotic outburst” that produced it is truly unique and one that travelers will revel in recalling when they visit Schrödinger sites. The role of probability and uncertainty in the interpretation of Schrödinger's “wave mechanics”, Heisenberg's “matrix mechanics” and Dirac's relativistic quantum mechanics is discussed in sufficient detail that travelers can begin to appreciate how they are incorporated into modern atomic theory. The nature of atomic orbitals as depictions of the probability of finding electrons in atoms is succinctly explained. Stories about Schrödinger's cat, Dirac's personality, Heisenberg's retreat to the North Seas island Helgoland where he invented “matrix mechanics”, and the enigmatic equation on Max Born's tombstone all contribute to the fun and adventure of traveling with the atom.