San Francisco S Exploratorium

Q: How do trick birthday candles that will not blow out work? A: According to scientists at San Francisco's Exploratorium, small particles of gunpowder are woven into the wick. When the candle is lit, you'll notice that the wick occasionally shoots off little sparks as it burns. When you blow the candle out, the wick continues to glow for a few seconds. The glowing wick is hot enough to ignite the gunpowder, which reignites the wick.

Something Incredibly Wonderful Happens Frank Oppenheimer and the World He Made Up K.C. Cole Houghton Mifflin Harcourt: 416 pp., $27 Skills or content? This is an age-old question in education, currently taking the form of "21st Century Skills" versus "Cultural Literacy." Simply put, should children be taught how to do things, or to know stuff? Both arguments have merit, but the problem with the skills-content dichotomy is that it leaves out an essential ingredient: the sense of curiosity, exploration and discovery, without which no learning can truly happen.

It's not always easy for Ned Kahn to explain what he does for a living. He's part artist, part scientist, part kid. And he uses things like water hoses, cloudy fluids and sand-like glass beads to create tornadoes and sandstorms. "Oh," said a businesswoman who once sat next to him on an airplane. "So you're kind of a fine arts plumber." Or a rebel with a hose.

It's not always easy for Ned Kahn to explain what he does for a living. He's part artist, part scientist, part kid. And he uses things like water hoses, cloudy fluids and sand-like glass beads to create tornadoes and sandstorms. "Oh," said a businesswoman who once sat next to him on an airplane. "So you're kind of a fine arts plumber." Or a rebel with a hose.

Something Incredibly Wonderful Happens Frank Oppenheimer and the World He Made Up K.C. Cole Houghton Mifflin Harcourt: 416 pp., $27 Skills or content? This is an age-old question in education, currently taking the form of "21st Century Skills" versus "Cultural Literacy." Simply put, should children be taught how to do things, or to know stuff? Both arguments have merit, but the problem with the skills-content dichotomy is that it leaves out an essential ingredient: the sense of curiosity, exploration and discovery, without which no learning can truly happen.

Q: How do trick birthday candles that will not blow out work? A: According to scientists at San Francisco's Exploratorium, small particles of gunpowder are woven into the wick. When the candle is lit, you'll notice that the wick occasionally shoots off little sparks as it burns. When you blow the candle out, the wick continues to glow for a few seconds. The glowing wick is hot enough to ignite the gunpowder, which reignites the wick.