An interesting and oft-investigated question, “What is the origin of light?” and the solution of it, has been repeatedly attempted, with no other result than to crowd our lunatic asylums with the would-be solvers. Hence, after fruitless attempts to suppress such investigations by making them liable to a heavy tax, the Legislature … absolutely prohibited them.
From Abbott’s Flatland
5.1a What Is Radiation Scattering?
In Chapter 1 we described dark-field microscopy in which particles too small for direct microscopic observation could be detected against a dark field by horizontal illumination. Airborne dust or smoke particles show in a beam of light in an otherwise ...