Q) Looking at a friend's heel blisters made me wonder: Why do people get squeamish?
Laverne D'Arcy, Winterville, North Carolina
A) ACCORDING TO Laura Campbell, a therapist at Boston University's Center for Anxiety and Related Disorders, that queasy feeling is actually a triumph of evolution: It tells you, in no uncertain terms, that ripping into flesh isn't healthy. When you witness something gory or smell rotting tissue, your brain fires the neural impulses that give you those heebie-jeebies. You feel both anxious and afraid of contaminationan emotional state psychologists define as disgust. Next, your sympathetic and parasympathetic nervous systems kick inreleasing adrenaline and glucose, raising your heart rate, and pumping larger-than-normal blood flows to the major muscle groups. This mild fight-or-flight response might seem like overkill in the case of a blister or small cut, acknowledges Campbell, but she says it's useful conditioning nonetheless: "Once it's over, you never want to make the same mistake."
Q) Is it true that when you get to a certain point near the North or South Pole, your compass stops working?
Tony Marzo, Copper Mountain, Colorado
A) Yes. Above the Arctic Circle and below the Antarctic Circle, compasses will deviate by as much as 180 degrees from true north. That is because the magnetic poles are about 1,000 miles from the true poles. But that's not a compass's only problem. Polar explorer Robert Peary reported after his 1891-to-1892 trip to the Arctic that his compass acted very "sluggish" and didn't always point north. When he sailed over the magnetic pole the source of magnetic attraction was directly beneath him, so rather than spinning north or south, the needle dipped downward. Explorers like Peary employed a variety of tools and techniques to chart their progress, including dead reckoning and a sextant, a device that measures latitude and longitude using celestial objects. Should you visit Nunavut or Tuktoyaktuk nowadays, you might want to bring a GPS and let satellites be your guide.
Q) Why do some people refer to fishing as "angling"?
Peter Troller, Boulder, Colorado
A) SPORT FISHING dates back 4,000 years to ancient Egypt, but "angling," the word for catching freshwater or saltwater fish with a rod, line, and hook, is derived from the Old English noun angul, which means "hook." According to Gary Tanner, executive director for the American Museum of Fly Fishing in Manchester, Vermont, a later cognate of "angle" appeared in written form in Parzival, an early-13th-century chivalric romance by the German author Wolfram von Eschenbach. In it Shionatulander, a young kinsman of King Arthur, catches trout and grayling with a feather-dressed "verderangel," an ancestor of today's woolly bugger.
Q) What do mosquitoes eat when people or other warm-blooded animals aren't around?
Dave Wyant, Phoenix, Arizona
A) YOUR FIRST MISTAKE is assuming that all mosquitoes bite people or other warm-blooded animals. Fact is, a large number of the world's roughly 2,000 mosquito species prefer birds, while others dine on cold-blooded critters, such as frogs, and wouldn't touch human or horse for a million bucks. Your second mistake (a common one) is assuming that blood is a mosquito's food source. Actually, they eat good old-fashioned carbohydrates, those found in fresh fruits, succulent grasses, and the nectar of flowers. So why on earth do mosquitoes bite animals? Females need the protein and amino acids found in blood in order to form their eggs, explains Wayne Crans, director of the Mosquito Research and Control Unit at Rutgers University. "If the females don't succeed," explains Crans, "they don't have babies." Males have no need for blood, so they don't bite people. After finding a mate and fertilizing her eggs, they bite the dust at the not-so-ripe age of four days.