# Examples of non-sine waves? [closed]

What would be a non-sine wave? AFAIK, all sound is a sine wave, equally to waves on the sea. What would be a common example of something in nature that's a wave but not a sine wave? Or, would we have to look at man made regularities like bus timetables or stock prices to find non-sine waves?

• I assume you're aware that most of these things are modeled as multiple sound waves in superposition, right? – JMac May 7 '19 at 17:36
• Waves on the sea are definitely not sine waves. Sound waves aren't sine waves either, unless you are listening to a tone of a single frequency – BioPhysicist May 7 '19 at 17:41
• @JMac: no, who models bus timetables as multiple sound waves in superposition? – Pierre B May 7 '19 at 17:41
• @PierreB Meant to say "sine waves", but the point basically stands. – JMac May 7 '19 at 17:42
• Every waveform can be decomposed into a sum of sine waves. – Nuclear Wang May 7 '19 at 17:44

Waves can take all sorts of funny shapes. This is especially true if the differential equation generating them is nonlinear. This makes fluid mechanics a wonderful source of complicated waves. My personal favourite example is the solutions $$\phi(x,\,t)=-\frac{c}{2}\operatorname{sech}^2\left[\frac{\sqrt{c}}{2}(x-ct-a)\right]$$ of the KdV equation. See here, here and here for more examples.