I cant really find anywhere on the internet that explains WHY, just that it is. If i throw a stone into the water, does it ripple sinusoidally? Why though? why not like a triangle wave? what is it about nature that makes it want to be siney?
my first thought is that transfers of energy into different vectors naturally happen gradually and not instantly. that's just my experience with acceleration, or just direction-change in general. however, that doesn't necessarily answer the question of why our universe is like this in the first place. although i've grown accustomed to it being that way and it seems normal. but i could also see it being normal the other way also. like how color changes in a photo are usually gradual, but you could also imagine a universe with only 2 colors and no gradients, and that would make its own kind of sense