Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. QED: The Strange Theory of Light and Matter is an adaptation for the general reader of four lectures on quantum electrodynamics (QED) by Richard Feynman (1918-1988). QED was designed to be a popular science book in a witty style with some quantum-mechanical mathematics. It is aimed at teaching its audience to understand what''s going on behind the calculations rather than teaching how to do the calculations. It was first published in 1985 by the Princeton University Press.