Place an ultracold neutron in a gravitational potential and you get a system whose quantized energy levels could be used to probe dark energy and dark matter. As Wolfgang Schleich and Ernst Rasel write in APS Physics: Spectroscopy has always set the pace of physics. Indeed, the observation of the Balmer series of the hydrogen atom led to the Bohr-Sommerfeld model about 100 years ago. A little later the discreteness of the spectrum moved Werner Heisenberg to develop matrix mechanics and Erwin Schrödinger to formulate wave mechanics. In 1947, the observation of a level shift in hydrogen by Willis E. Lamb ushered in quantum electrodynamics.
Posted on: Wed, 16 Apr 2014 17:25:11 +0000