Source: cirosantilli/the-wave-equation-can-be-seen-as-infinitely-many-infinitesimal-coupled-oscillators
= The wave equation can be seen as infinitely many infinitesimal coupled oscillators
TODO confirm, see also: <coupled oscillators>. And then this idea can be used to define/motivate <quantum field theory> in terms of <quantum harmonic oscillators> with <second quantization>.
* https://youtu.be/SMmFgIEGYtw?t=324 Quantum Field Theory 2a - Field Quantization I by <ViaScience> (2018)