The Ocean's Rhythms and Other Natural Oscillations
2. Sine Waves in the Wild
Now, where do we actually see these sine-wave-ish things in nature? A great example is ocean waves. While a single wave crashing on the shore is a chaotic, spume-filled event, the overall pattern of waves coming in and out often approximates a sine wave. You'll notice that the water level rises and falls more or less rhythmically. You can even estimate the wavelength and frequency.
Sound is another fantastic example. When you pluck a guitar string or listen to a bird sing, the vibrations in the air travel as waves. And guess what? Those sound waves, particularly pure tones, are very close to sine waves. In fact, early electronic music synthesizers used oscillators designed to generate sine waves as the building block for more complex sounds.
Even light can be described using sine waves. In fact, electromagnetic radiation, including visible light, radio waves, and X-rays, propagates as waves. Each wavelength of light vibrates in a sinusoidal pattern. The color of light we perceive depends on its wavelength which correlates to the sine wave's properties. So, indirectly, sine waves are responsible for the beautiful blue of the sky or the vibrant colors of a rainbow.
Beyond the immediate senses, the cyclical changes in the populations of animal species can also be modeled using sine waves. Predator-prey relationships, where the number of predators increases as the number of prey increases, only to decline again as the prey population dwindles, forms an oscillating pattern that can be represented using sine waves. Seasonal changes, too, such as temperature fluctuations and day length, display sine-wave-like behavior over the course of a year.
