Yet American physics circa 1900 was characterized by experimental virtuosity, by developing apparatus to measure extremely small effects. Henry Rowland's
diffraction gratings, Michelson and Morley's interferometer, Millikan's oil-drop apparatus for measuring electric charge, and Nichols' and Hull's
radiometer required extraordinary skills in instrument-making, experimental design, error reduction and patience, producing a kind of "measuring physics"
that historians of physics have called peculiarly "American" in those years [Goldberg and Steuwer, eds., The Michelson Era in American Science, 1870-1930
(1988)]. These experiments were a tour de force 110 years ago. They remain today a tour de force. Any experimentalist who reads the original papers will
be amazed at the skill, attention to detail and the level of sensitivity and numerical accuracy achieved by Nichols and Hull with such basic equipment.
Radiative light forces have since found many applications including laser cooling, trapping, and manipulation (optical tweezers) of neutral atoms and molecules.
Radiative forces are used to manipulate atoms to form exotic states of matter, such as Bose-Einstein condensates, optical molasses and optical crystals,
and to facilitate delicate high precision atom beam interferometers. The radiation pressure of soft x-rays is the basis for nuclear fusion confinement in
the Teller-Ulam method of hydrogen weapon technology.
Recently, there has been a significant growing effort to perform the quantum version of the Nichols-Hull experiment, in particular to measure the photon shot noise force on a macroscopic object. Such a back reaction force sets fundamental limits to the sensitivity of force meters and is for example relevant for gravity wave detection. The pioneering work of Nichols and Hull, and of Lebedev, is cited in recent optomechanics papers, workshops, conferences and Nobel Lectures [see for example, the one of W. D. Phillips (1997)]. It is clearly recognized as the starting point for all modern radiative force techniques in the manipulation of atoms and macroscopic bodies.
