Wave and Partical Optics

For any man with half an eye,
What stands before him may espy;
But optics sharp it needs I ween,
To see what is not to be seen.

(Ptolemy) left in his Optics, the earliest surviving table of angles of refraction from air to water. ...This table, quoted and requoted until modern times, has been admired... A closer glance at it, however, suggests that there was less experimentation involved in it than originally was thought, for the values of the angles of refraction form an arithmetic progression of second order... As in other portions of Greek Science, confidence in mathematics was here greater than that in the evidence of the senses, although the value corresponding to 60° agrees remarkably well with experience.

Music is the arithmetic of sounds as optics is the geometry of light.