Science File / An exploration of issues and trends affecting science, medicine and the environment

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.