There is some new stuff at junkyardinnovations.(com)regarding Sine waves in relation to how one arrive at a Sine wave from a more complex waveform.
Usually it is the use of the Sine wave shape fundamental to generate other waves shapes that take our notice.
These accidentally found variable wave shapes that result in a
Sine Wave when in a special relationship may have an interesting application to our understanding of physics if found to exist in nature. Check it out. Thanks.