Q) Is human hair a good insulator?
You hear it on every flight, but has anyone ever used a SEAT CUSHION AS A FLOATING DEVICE? Yes, in at least two cases, those butt savers have probably really saved butts. In 1978, when an Antilles Air Boat went down near the U.S. Virgin Islands, survivors grabbed on to cushions that had popped free; and after the aborted 1989 takeoff of a USAir 737 at LaGuardia Airport, flight attendants tossed seat bottoms to passengers in the chilly water, some of whom couldn't swim. Seats are allowed as flotation devices only on inland flights; as NTSB investigator Mark George explains, the FAA requires planes with extended over-water routes to carry more-buoyant life preservers and inflatable rafts. But those devices take time to prepare, and time is scarce in plane ditchings. Maybe that's wh...
The Wild File
Nathan Johnson, Los Angeles
A) A material's ability to keep you warm is a function of how much air it can trap. The trapped air, not the fiber itself, does the insulating. According to Yash Kamath, a materials scientist at TRI/Princeton, a New Jerseybased textile-research institute, the more crimped a fiber is, the more open structure it has for holding air. Wool, for example, is far more twisty than human haireven a Rastafarian'sso although both fibers are made of the protein keratin, a wool hat will keep heat in far better than any head of hair. But before you start rethinking your hat inventory, be advised that the oft-cited claim that you lose most of your heat through your head is a myth. In fact, only 10 percent of your heat leaks out via the noggin, says Daniel Sessler, an anesthesiologist at the University of Louisville School of Medicine. It was a faulty 1950s study, coupled with the head's sensitivity to cold, that gave rise to the belief. A hat is a smart choice, but it's no more crucial than any other skin-covering item.
Q) What's the most common tree?
Neil Harrison, Reed City, MI
A) You might assume the most ubiquitous tree would be a rainforest specimen, but it's not so: Those sweaty jungles are a crowded mosaic of different species. Peter Lee, a biologist at Global Forest Watch Canada, says that the John Smith of trees is the Siberian larch, numbering in the high hundreds of millions in the forests of eastern Russia, Siberia, and northern China. While no one has done a full count, this deciduous conifer's wide distribution in Russia's boreal (northern) forests, which are three times the size of North America's, places it ahead of two runners-up, the black spruce of Canada and Russia's Siberian spruce. For both the long-lived larch and the spindly but hardy spruce, an effective propagator, global warming is a serious concern. As temperatures rise, their range will be pushed farther north and they'll become more susceptible to fire. Both factors could devastate the boreal forests and, as with the rainforests, the results would be unpleasant for, well, all life on earth.
Q) What is the smallest dinosaur ever found?
Jerri Callantine, Ogden, UT
A) From 1859 until recently, the three-foot-long Jurassic-period Compsognathus longipes, a fleet-footed lizard eater, held the title. But a recent find has bumped Compsognathus off its itty-bitty throne. According to University of Maryland paleontologist Thomas Holtz, Microraptor zhaoianus, unearthed in China's Liaoning Province in the late 1990s, is now the smallest of the giants. Micro, which measured about 16 inches from snout to toe, resembled its relative the velociraptor, but with a few avian extras: It lived in trees and had a special toe for grasping branches. Why did it evolve to be so shrimpy? While its Cretaceous-period cousins were chowing on larger prey, the small-mammal population skyrocketed. There was a niche to be filled, and Micro stepped up to the plate.