As the title of this blog suggests, in science data comes before everything else. All theories must yield to measurements. One of the great empiricists of all time, Richard Feynman, has said this better than anyone.
The famous "Feynman Lectures" can be bought as a collection. But they're also available online. Here's the first of a series of seven - Feynman talking about gravitation, and how we know that a principle of science is, in fact, a natural law.
Go listen to the others, too. In addition to being one of the forerunners of the great popularizers of science like Carl Sagan and Neil Degrasse Tyson, his Queens accent makes listening to discussions of Brahe, Copernicus, Galileo, Newton and Einstein a positive joy.
Don't miss it. Cheers,