If you've ever blown on kindling to start a campfire, you know there's a fine line between puffing hard enough to increase the oxygen available to the fire and blowing so hard that it goes out. So why does BLOWING ON A FLAME extinguish it? Eric Eddings, a chemical engineering prof at the University of Utah, says, "Flames are a product of a complex chemical reaction between a fuel source and oxygen in the air." When fuel, such as wood, is heated, its cellulose plant material breaks down and volatile gases are released. Once oxygen mixes with these gases, a spark will set it ablaze. When you blow gently on a fire, you put more O2 into the equation and increase the rate of burning. Blow too hard and any of fire's three requisite elements can be removed: The fuel-oxygen mixture can g...
Q) If a fly gets trapped in my car and I drive 50 miles, what happens to it when it escapes?
Nell Gharibian, Boston, Massachusetts
A) This is a case where being less socially advanced is a good thing. A honeybee can't find its way home from more than a mile away, and it would be rejected by hives in a new territory and die within days. Houseflies, which don't form the same complex social structures as bees, would stay on their new turf and get along just fine. According to Lee Townsend, an entomologist at the University of Kentucky, a fly would simply follow its nose around in pursuit of the rotting organic matter that it lives on. Its only contact might be with the other flies at a popular dung pile, where, picking up chemical signals put out by the opposite sex, it could find a mate. The pair's relationship would be briefflies don't waste time on courtshipand then the male, for the remainder of its two-week life span, would head off in search of more gooey dead stuff. If you're a fly, how could you ask for anything more?
Q) Are humans born with all of their bones?
Justin Berry, Bemidji, Minnesota
A) Sort of. While we come into the world with a complete skeletal system, about 50 percent of it starts out as cartilage, which is much softer and more flexible than bonea definite plus when it comes to squeezing through the birth canal, says Hans-Georg Simon, a developmental biologist at Northwestern University's Feinberg School of Medicine, in Chicago. Cartilage is also quite handy because it allows the bones to harden graduallyor "ossify," in white-coat lingoas a baby bounces on into childhood. In some places, such as the hands and the skullpicture the soft spot on a baby's headseveral infant bones fuse together and form new, larger bones. So, over time, we actually go from having about 300 bones (some of them cartilaginous) down to 206. By the end of puberty, when most of your cartilage has hardened, bones stop growing longer and your skeleton is a finished work of art.
Q) What creature can consume the most food in one day, relative to its own weight?
Mike Fountoulakis, Plano, Texas
A) Although Japanese world champion hot-dog eater Takeru Kobayashi can eat up to 6 percent of his own weight in wieners, that's put to shame by many beings higher up the gluttony scale. The spotted hyena (more a hunter than a scavenger) can wolf down one-third its own body weight, even the hooves and bones, while two other voracious mammalsthe tiny masked shrew and the vampire batcan gobble and slurp (respectively) a full 100 percent of their weight in 24 hours. Scarier yet, some deep-sea-dwelling, sci-fi-looking breeds of anglerfish, which attract prey by dangling a bioluminescent lure from their foremost dorsal spine, can take down fish their own size in a single gulp. Still, these daunting fuel capacities are eclipsed by some caterpillars. During its final growth stage, the constantly feeding larva of a monarch butterfly consumes an amazing 2.25 times its own weight in milkweed per day. Eat your heart out, Kobayashi.