Physicists measure the spectrum (the intensity of light as a function of wavelength, or color) of a light source in a spectrometer. The figure below shows a schematic drawing of a simple prism spectrometer. White light comes in from the left and t...

Hans Bethe introduces quantum theory as "the most important discovery of the twentieth century" and shows that quantum theory gave us "understanding and technology." He cites computers as a dramatic realization of applied quantum physics.

Scientists Now Uncertain About Heisenberg's Uncertainty Principle. David Deutsch's The Fabric of Reality connects the spookier elements of quantum mechanics. And now, Richard Feynman playing the bongos.