Deep inelastic collision between an electron and a proton, where the nucleon is viewed either (a) as a blob that breaks up or (b) as composed of quarks, one of which is ejected by elastic scattering with the electron.
Optical prism, consisting of a refracting medium bounded by two surfaces. Dispersion of light into its component colors is shown. (After W. J. Smith, Modern Optical Engineering, 3d ed., SPIE Press–McGraw-Hill, 2000)
Pentaprism, used in single lens reflex cameras. (a) Perspective view, showing how the prism deviates light through an angle of 90° without inverting or reverting the image. (b) Ray diagram. (After R. E. Hopkins and R. Hanau, U.S. Military Handbook…
Set of two thin prisms, known as optical wedges, which can be used as an alignment device. (After P. R. Yoder, Jr., Non-image forming optical components, in Geometrical Optics, SPIE Proc., 531:206–220, 1985)
Calcite concretion formed in Paleocene marine siltstone, Moeraki beach, New Zealand. Uncemented siltstone has been eroded away by wave action. Concretion is about 2 m (7 ft) in diameter, which is unusually large.