Submit your own photos of “visual physics”: email pictures to tpt@appstate.edu
While visiting Reykjavik, Iceland, last July, I photographed the Harpa Concert Hall with its kaleidoscope of reflections and colors in the several thousand glass panes that variously adorn the building (Fig. 1). When I crossed the boulevard to take a closer picture (position A in Fig. 1), I not only noticed that some of the panes were mirrors, but one of the mirrors about 10–12 m above me (B in Fig. 1) reflected the image of another tourist some distance from me (at C in Fig. 1) also taking a picture of the building. The law of reflection for the light following the path from the other tourist to me, path CBA, came to mind—the angle of incident rays as measured from the normal to a mirror’s surface equals the angle from the normal...