Wave Mechanics
It's customary to speak of wavelengths, and similar periodicities, in water waves. But when one examines the ocean, it turns out that waves are far from regular in shape and period. Today I went to the oceanside, and recorded a 3-minute video of waves coming ashore and crashing over a large rock. There was a moderate but steady breeze from offshore, perhaps 15 km/hr, and the time was about 1 hour after low tide.
Examining the video, each time the leading edge of a wave crashed over a particular part of the rock, I noted the time interval between that wave's arrival and the prior wave's arrival. A little perl program helped with recording the time information; I simply had to press the enter key everytime a wave was noted, and the program did the rest of the calculations.
The results: 22 waves arrived in the video, hence 21 intervals, total of 168 seconds or an average of 8.0 seconds between waves. Intervals ranged from 4.1 to 14.2 seconds, and the standard deviation of wave intervals was 2.8 seconds. Hardly a monofrequency wavefront!
I also noticed instances of waves running off at angles from the main wave front, water against water effects, not rock reflections, although it is possible there were reflections off the underwater bottom involved.
Serious study of wave mechanics, of actual waves, is not a trivial task!
Once again, we see that Hamlet has it right: There are more things in heaven and earth, than are dreamt of in our philosophies.
Examining the video, each time the leading edge of a wave crashed over a particular part of the rock, I noted the time interval between that wave's arrival and the prior wave's arrival. A little perl program helped with recording the time information; I simply had to press the enter key everytime a wave was noted, and the program did the rest of the calculations.
The results: 22 waves arrived in the video, hence 21 intervals, total of 168 seconds or an average of 8.0 seconds between waves. Intervals ranged from 4.1 to 14.2 seconds, and the standard deviation of wave intervals was 2.8 seconds. Hardly a monofrequency wavefront!
I also noticed instances of waves running off at angles from the main wave front, water against water effects, not rock reflections, although it is possible there were reflections off the underwater bottom involved.
Serious study of wave mechanics, of actual waves, is not a trivial task!
Once again, we see that Hamlet has it right: There are more things in heaven and earth, than are dreamt of in our philosophies.