File:Wine glass caustic example.jpg

Summary
More information on the physics of the image can be found in the following publication: "Wine glass caustic and halo analogies", Appl. Optics Vol. 57(19), pp. 5259-5267 (2018), https://www.osapublishing.org/AO/abstract.cfm?uri=AO-57-19-5259
 * Other information: