The temperature data came from the National Oceanic and Atmospheric Administration’s National Climatic Data Center website. It’s part of the federal government.
Nobel Prize-winning physicist Richard Feynman gave a talk at Cornell in which he pronounced the “key to science.” In short, if your theory about how the world works has yielded predictions that are contradicted by observations, then your theory was wrong. Period.
Feynman Chaser — The Key to Science [1:02]