Preparing a harmonic oscillator in a state with a well-defined energy is a tricky business. With the new tools provided by cavity and circuit quantum electrodynamics it is now possible to make these pure quantum states and watch how they evolve in time.
Physics1, 20 (2008) – Published September 15, 2008
Thick layers of disordered materials, such as milk or snow, scatter light so that very little of it gets through. Theorists say that a properly designed combination of incident light waves would be almost completely transmitted and we now have experimental proof of this remarkable result.