Wave Interference on Small Pool

November 29, 2014

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Photographer: Greg Stablein
Summary AuthorGreg Stablein
Shown above is a fine example of wave patterns resulting from falling water drops as observed at Mammoth Cave, Kentucky. When the falling drops hit the water surface they act as point sources of circular waves. As the waves or ripples travel outward over the surface of the water, they constructively or destructively interfere with neighboring waves. Note that portions of the wave patterns are alternatively light and dark. This caustic network results from the wave interaction on the surface of the water. An upward pointing wave crest acts as a convex lens that bends light from my camera's flash to create bright areas on the bottom of the pool. Conversely, a trough in the water surface acts as concave lens that disperses light from the flash resulting in the darker area on the pool's bottom. Photo taken June 2, 2007.
Photo details: Camera Maker: FUJIFILM; Camera Model: FinePix S5100; Focal Length: 5.7mm; Aperture: f/2.8; Exposure Time: 0.020 s (1/50); ISO equiv: 100; Flash Fired: Yes (Auto, return light detected); Software: QuickTime 7.6.4.