In addition to refraction (prism) and reflection (polished floor) diffraction is characteristic of the wave behaviour of light. Investigated by Thomas Young (slits figure) and used by Duality to couple light in and out of chips, diffraction can be observed in nature. The softening of the edges of the person in the window is from diffraction. The image of the galaxy cluster SMACS 0723, known as JWST’s First Deep Field shows stars with diffraction spikes caused by the supporting vanes around the secondary mirror. (But the Dali style fried egg galaxies are from gravitational lensing.)
Image credits: From T. Young, “Course of Lectures on Natural Philosophy and the Mechanical Arts,” 1807 and JWST Image.
