Theoretically speaking, the sine wave might be the purest expression of a wave, a simple oscillation between two points over time. Wave phenomena expressed in the natural world rarely follow such simple formulae, but nevertheless hold to it’s basic patterns.
Light waves, sound waves, the lengthening of days and shortening of days as the earth spins on it’s axis, there’s no end to examples of the wave phenomena in nature.
But hold up, this is nuts… think about this one… I’m about to make a big claim here… and it’s this:
There is only ONE wave phenomena in nature that exists at a scale that allows our human bodies to interact with, play with, be driven along and tumbled by, to be nearly killed, to makes us grin like children, to ride it’s single solitary wavelengths one at a time. Waves in water.
I challenge you to think of another. I’m stumped. All others we experience either passively (they can’t move us along with them) or collectively (like sound where we perceive its vibrations but our bodies are not moved by individual waves within those vibrations).