For the uninitiated, quantum mechanics are ostensibly non-physical, existing more in theory than in actuality. The classic quantum thought experiment, Schrödinger’s Cat, underscores this: How can a cat that is simultaneously alive and dead inside a box be anything more than a philosophical plaything?
A lot more. In fact, our world depends on it. Without quantum mechanics, atoms would fall apart, collapsing into nothingness. Without quantum mechanics, we would not have the modern world we have today.