Quantum mechanics is perhaps the most unintuitive theory ever devised. And yet it’s also the most successful, in terms of sheer predictive power. Simply by following the math of quantum mechanics, incredible discoveries have been made. Its wild success tells us that the mathematical description provided by quantum mechanics reflects deep truths about reality. And by far the most successful, most predictive formulation of quantum mechanics is quantum field theory. It is our best description we have of the fundamental workings of reality. And the first part of quantum field theory that was derived – quantum electrodynamics – is the most precise, most accurate of all.