Batchelor, Murray T.2015-12-152015-12-150031-9228http://hdl.handle.net/1885/95035Hans Bethe introduced his now-famous ansatz to obtain the energy eigenstates of the one-dimensional version of Werner Heisenberg’s model of interacting, localized spins in a solid. Although it is among Bethe’s most cited works and has a wide range of applications, it is rarely included in the graduate physics curriculum except at the advanced level. The 75th anniversary of the Bethe ansatz is appropriately marked by reflecting on the impact of Bethe’s result on modern physics, ranging from its profound influence on the field of exactly solved models in statistical mechanics to insights into the subtle nature of quantum many-body effects observed in cold quantum gases.http://www.sherpa.ac.uk/romeo/issn/0031-9228..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 16/12/15). Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics Today and may be found at https://doi.org/10.1063/1.2709557Keywords: Bosons; Heisenberg model; Heisenberg spin chain; Function evaluation; Ground state; Mathematical models; Superconducting materials; Wave equations; Quantum theoryThe Bethe ansatz after 75 years200710.1063/1.27095572016-02-24