H A R M O N I C
It may seem counter-intuitive, but our shared reality is all about harmony. Not just the harmony of people living together that way, but also because of a thing called Harmonic Resonance.
You may know of the concept through music: when two identically tuned guitars (or to identical tuning forks) are near one another, and you excite a string on one of them, the corresponding string on the other guitar will start to vibrate also. The same can also happen if the resonant resonant frequency of one string is a multiple of the other one.
Actually, this concept is not just limited to music, or even light: it is applicable to every wave concept, whether in sound, energy, or even in a thing as seemingly far removed from this as for instance a bridge in the wind! There are several good examples of bridges that developed severe vibrations because of prevailing winds. A very recent example was the pedestrians bridge across the Thames in London. Additional reinforcements were needed, to shift the resonant frequency from what it used to be.