June 12, 2008
While standing along the railing of a whale watching boat, hoping in vain to actually see a whale, I entertained myself by taking high-speed photos of the vessel’s bow wave. When I got home and took a good look at the images, I was amazed to see these beautiful repeating patterns in all the bow waves. An object (such as a boat) moving at the same speed as the waves it creates will generate circular waves. However, when the boat moves faster than the waves, the waves begin to "pile up" at the front and overlap. The points at which adjacent waves overlap forms the familiar V shape we see fanning out from the sides of the boat. As the boat moves faster, the V shape becomes narrower. The phenomenon is similar to sound waves that pile up in front of an airplane as it approaches the sound barrier, but those waves result in a sonic boom as the plane crosses that threshold. Photo taken on January 19, 2008, from near Long Beach, California.