The two 1.3-cm apertures do not produce two separate images, but rather two
images superimposed upon each other. Again, the fact that
this is so was just demonstrated previously. However, as in
Thomas Young’s famous double slit experiment,2 an alternat-
ing pattern of constructive and destructive interference bands
is now present in the image. These are like Young’s fringes
produced by two 1.3-cm holes rather than two slits. As in the
case of Young’s experiment, the fringe spacing can be shown
to vary with the hole separation: the farther the holes are
moved apart, the closer the fringe spacing, as is shown in the
five images in the left column of Fig. 2.