I adore the blessed people who write up the Simple English entries.

Here’s the opening paragraph from Quantum Mechanics in Simple English:

Quantum mechanics explains how the universe works with things that are even smaller than atoms. It is also called quantum physics or quantum theory. Mechanics is the part of physics that explains how things move and quantum is the Latin word for ‘how much’. A quantum of energy is the least amount possible (or the least extra amount), and quantum mechanics describes how that energy moves.