On this day in 2006, the one billionth song was downloaded from iTunes. In 1954, the first mass vaccination against polio began in Pittsburgh, Pennsylvania. In 1893, Rudolf Diesel patented the diesel engine, and in 1455, the Gutenberg Bible was published. Happy Birthday Michael Dell (1965), Tom Bodett (1955), Brad Whitford (1952), and Peter Fonda (1940). RIP Howie Epstein (d.2003), Stan Laurel (d.1965), Carl Friedrich Gauss (d.1855) and John Quincy Adams (d.1848). "Science is what we understand well enough to explain to a computer. Art is everything else we do." - Donald Knuth