A very high reader in California wants to know how altitude affects the performance of a car. As you chug up 8,600-foot Carson Pass, you might feel less oomph when you step on the gas—but there's no use banging on the dash. Air density decreases at elevation, resulting in a lower concentration of oxygen reaching your engine's combustion chamber. And while modern cars come with fuel injectors that compensate to maintain a high-rev air-to-fuel ratio of about 12 to 1, that means your ride gets smaller sips of juice, reducing power. High-altitude gas stations often stock fuel formulated for thin-air combustion, but that only slightly improves performance (and reduces emissions). According to Steve Hatch, an instructor at the Denver Automotive and Diesel College, the best way...
Q) How long could my dog last in the wild?
Laurie England, Washington, D.C.
Parachute your pooch into Idaho's 2.3-million-acre Frank Church–River of No Return Wilderness and chances are he won't make it to Christmas—almost certainly not if he's a Chihuahua, Pomeranian, or any other undersized canine variety. The problem isn't just food or shelter. According to Marc Bekoff, a University of Colorado biologist who oversaw a study of feral dogs in Newark, New Jersey, and on the U.S.-Mexico border near El Paso, many dogs can hunt small mammals and reptiles and can handle harsh weather. But toothy predators are likely to make a meal out of Fifi within weeks; if he's a battle-hardened German shepherd, maybe a couple of years. The wayward weimaraner's best strategy? Hook up with other hounds. "Feral packs can form a formidable defense against a bear or wolf," says Bekoff. Luck helps, too. Just ask Sasha, the shih tzu who in 2002 dodged deadly snakes and raptors on a seven-week trek across Australia's Blue Mountains.
Q) Do couples living together end up carrying the same array of germs and bugs?
Bridgette Kolias, Seattle, Washington
According to Philip Tierno, director of microbiology at New York University Medical Center and author of The Secret Life of Germs, even if you were tied to your lover 24/7, the assortment of 500-plus bacteria species in your throat and 100 million symbiotic flora in your intestines would remain unique. That's because they're constantly changing, depending on many specific-to-you variables like hormones and the health of your immune system. "Different people's bacteria respond differently to their environments," says Tierno. "Living together doesn't mean you'll take your partner's organisms." Yes, some strains of sweetie's cooties might invade your innards, but they won't all be permanent. In fact, the only sizable person-to-person transfers of internal flora are from mother to child during birth. So, come Mother's Day, consider sending Mom the card she deserves: "Thanks for all the bugs!"
Q) Can a flower's aroma be diminished by a large number of sniffers?
Diana Marquardt, Del Mar, California
The 10,000 or so odors the human nose can pick out travel up our schnozzes via odorants, the airborne molecules emitted by smelly things. The more odorants released, the stronger the smell. That's why a peeled orange, which liberally perspires limonene molecules, can perfume a room, while a brick of gold, which gives off practically no odorants, is almost scent-free. Once inhaled, odorants bond with some of the 350 types of receptor proteins in the olfactory epithelium, at the back of the nose, telling the brain important information like "You've burned your Hungry Man again." So is it possible to sniff up all the odorants from a pocketful of posies? Nope. According to neurobiology professor Michael Leon, of UC Irvine, anything with an aroma releases hundreds of millions of odorants, and the receptors in a single honker can bind with only a few thousand. Even an army of Cyranos couldn't Hoover up all the smell.