|English physicist Thomas Young's circa 1804 double-slit experiment with light and the interference fringes produced, as diagrammed in his 1807 Natural Philosophy. |
"Though Descartes may be mistaken so is Mr Hook."
|Sketch of English physicist Isaac Newton's circa 1666 double prism, double perforation experiment, from his notebook, in which he showed that an isolated beam of colored light shined through a prism did not create new colors, contrary to the prevailing theory that prisms somehow added color to white light. |
|Depiction of Thomas Young's famous circa 1804 double slit experiment.  Depiction of two waves producing constructive interferences (left) and destructive interferences (right).|
“I maintain that when two portions of light are mixed, elevations or depressions in the undulations will result, similar to the way in which waves of colliding water combine in their effects, and I call this the general law of the interference of light.”In 1802, to elaborate on his theory, by analogy with water waves, Young built a "ripple tank" (below), with a glass bottom and board for creating ripples on one end, arranged such that if light was allowed to illuminate the bottom of the tank, the interference of the ripple patterns could be observed on a board placed above the tank at an angle.
|Ripple tank (top) and interference of two water waves (below) in the ripple tank, as diagrammed in Young's 1807 Natural Philosophy. |
“It is daydreaming. What counts is what you see on the screen. Do not ask if the particle did follow some continuous path. We do not know about that. Forget about it.?”— Martinus Veltman (2003), Facts and Mysteries in Elementary Particle Physics