Pythagoras plucked a string 2,500 years ago and wondered whether the whole universe was built like music.

Then in 1968 a formula from Leonhard Euler turned up in particle physics and no one could explain why it worked. It turned out to describe vibrating strings. https://www.youtube.com/watch?v=xwaJQPytXuY , https://www.youtube.com/@4physics-tomath/videos