The Writer's Almanac with Garrison Keillor

English chemist and physicist Michael Faraday discovered the principle of electromagnetic induction on this date in 1831. He wrapped two coils of wire around an iron ring. When he passed an electrical current through one coil, the current was also registered in the other coil. He found that rotating a magnet over a coil produced an electric current, which could also be detected in the second coil. The movement of the magnet's poles changed the magnetic field, and it was that change that generated the current. The bigger the change, the greater the voltage that was produced. If Faraday held a magnet steady, the field did not change, and no electrical field was produced. Later, James Clerk Maxwell expressed Faraday's discovery mathematically, and he named the resulting equation "Faraday's law of electromagnetic induction." This equation, along with three others formulated by Maxwell, gave rise to electromagnetic field theory. Faraday's discovery paved the way for the invention of the electric transformer and generator, turning electricity from a scientific novelty to a powerful technology; his principle is behind virtually all electric power produced in the world today, regardless of the original source of the energy.

It's the birthday of British philosopher John Locke (books by this author), born in Wrington, Somerset, England (1632). He believed in Natural Law and that people have Natural Rights, under which the right of property is most important. He wrote: "... every man has a property in his own person. This nobody has any right to but himself." He believed government exists to protect those rights and he argued in favor of revolt against tyranny. His ideas were a foundation for much of the Declaration of Independence and the U.S. Constitution.

It's the birthday of poet and physician Oliver Wendell Holmes Sr. (books by this author), born in Cambridge, Massachusetts (1809). He ran in the same circles as Ralph Waldo Emerson, Henry Wadsworth Longfellow, and other Boston intellectuals. He helped found The Atlantic Monthly magazine in 1857, and it was Holmes himself who came up with the name. He published his poetry and articles in The Atlantic Monthly at the same time he practiced medicine and taught at Harvard Medical School. He's also the father of U.S. Supreme Court Justice Oliver Wendell Holmes Jr.

He's perhaps best-known for his essays that make up the "Breakfast Table" series. In The Poet at the Breakfast Table (1872) he wrote, "We are all tattooed in our cradles with the beliefs of our tribe; the record may seem superficial, but it is indelible."
He said: "Insanity is often the logic of an accurate mind overtasked. Good mental machinery ought to break its own wheels and levers, if anything is thrust among them suddenly which tends to stop them or reverse their motion. A weak mind does not accumulate force enough to hurt itself; stupidity often saves a man from going mad."

It's the birthday of jazz saxophonist Charlie Parker, born in Kansas City, Kansas (1920). He is considered one of the half-dozen greatest jazz musicians, right up there with Duke Ellington and Louis Armstrong. Early in his career, he received the nickname of "Yardbird," and then he became known as "Bird."

Before Parker's innovations, jazz meant swing, melodies played at dance tempos by musicians in big orchestras who never got to take solos for very long. Late at night, after their big-band jobs were over, Parker, Dizzy Gillespie, and other black musicians kept on playing, improvising long lines at blazing speed. Parker used a lot of flatted fifths, and jazz players used the word "bebop" to sing a flatted fifth, but Parker didn't like to use the word for the way he played. "Let's not call it bebop," he said. "Let's just call it music."

Parker said: "I realized by using the high notes of the chords as a melodic line, and by the right harmonic progression, I could play what I heard inside me. That's when I was born."