> The law of conservation of momentum was created before quantum mechanics was discovered. The law of conservation of momentum is a fundamental part of quantum

> The law of conservation of momentum was created before quantum mechanics was discovered. The law of conservation of momentum is a fundamental part of quantum field theory; without it, we don't have particle accelerators, nor any understanding of particle decay. I strongly suggest, well, everything on this site, but in particular, https://profmattstrassler.com/articles-and-posts/particle-physics-basics/why-do-particles-decay/most-particles-decay-yet-some-dont/ https://profmattstrassler.com/articles-and-posts/particle-ph... and https://profmattstrassler.com/articles-and-posts/particle-physics-basics/why-do-particles-decay/most-particles-decay-yet-some-dont/ https://profmattstrassler.com/articles-and-posts/particle-ph... . It's the best review of modern physics I've seen anywhere that is both accessible to a lay-but-interested reader, and aligns correctly with the actual math.