Who knew pinball was once considered dangerous? Naysayers saw it as a form of gambling, and the game was banned from the 1940s to the 1970s. The good folks at the Pacific Pinball Museum in Alameda think pinball isn’t a crime, but rather a fun way to pass a summer afternoon, not to mention an excellent demonstration of scientific principles such as physics and electricity. The museum’s price of admission ($15 for adults, $7.50 for kids under twelve) gets you free unlimited play on its ninety machines, which include such treasures as an 1879 Montague Redgrave Parlor Bagatelle and 1940s Mystic Marvel, plus contemporary games like The Simpsons and Creature from the Black Lagoon. On the science side, don’t miss the Visible Pinball Machine — which shows how the game works while the ball is in play — and the Pinbowl Chaos Generator, which demonstrates that eternal principle: Chaos happens.