Health & Science

The physics of feline drinking

Cats show a mastery of fluid dynamics every time they take a drink of water, researchers have found. Like most other carnivores, they can’t fully close their mouths to create suction the way humans do. Dogs solve the problem by curling their tongue into a cup-like shape and scooping up water, which can be a sloppy process. Cats are classier. Using a high-speed camera, researchers at MIT learned that a cat curls the tip of its tongue downward and merely touches it to the water’s surface. As the tongue is quickly drawn back, it pulls up a column of liquid, which the cat captures by snapping its jaws shut. The key is timing: Cats know instinctively when the inertial force that keeps the water flowing upward will be overcome by gravity pulling it downward. “There is a time when the volume of a column is at a maximum, which is the time at which the cat closes its jaw,” study author Roman Stocker, a biophysicist at MIT, tells BBC.com. The researchers calculated the ideal lap rate for felines of different sizes and confirmed it by filming big zoo cats as they drank. Stocker had been moved to study the phenomenon by watching his own cat, Cutta Cutta, lapping at its water bowl. “I realized there was an interesting biomechanics problem hidden behind that very simple action.”

The heavy have better noses

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Overweight people have a heightened sense of smell, reports the London Telegraph, and that may be one reason why they eat too much. Researchers in England exposed a small group of volunteers, both slim and overweight, to the odors of cooking herbs in varying potency. They found that people are generally more sensitive to food smells after eating than before, and that the effect is even more pronounced for overweight subjects—particularly if they’ve eaten a full meal. This group’s “higher sense of smell for food-related odors” may encourage them to keep eating when they don’t need to, study author Lorenzo Stafford, a psychologist at the U.K.’s University of Portsmouth, tells BBCnews.com.

Job stress harms women’s health

Having a stressful job raises a woman’s risk of needing heart surgery by 40 percent and almost doubles the likelihood that she’ll have a heart attack. Those are the sobering conclusions reached by Michelle Albert, a cardiologist at Brigham and Women’s Hospital in Boston, based on a long-term study of more than 17,000 mostly older white women employed in health care. The women were asked in 1999 to assess how much stress they encountered at work. Ten years later, Albert found that those classified as having the most demanding jobs—and the lowest sense of control over how they do them—are paying a high price in cardiovascular health. The link between job-induced stress and heart problems has been well established for men, but this federally funded study is the most significant look yet at its impact on women, who make up 47 percent of the workforce while bearing a heavier burden than men at home. “Women have to be particularly attuned to the issue of various stressors in their lives and seek help to manage them,” she tells NPR.org.

The downside of daydreaming

Many people may wish they had more time for daydreaming, but a study by Harvard researchers has found that people are actually less happy when their minds are wandering. Through the website Trackyourhappiness.org, more than 2,200 volunteers downloaded an app for their iPhones that asked them at random intervals what they were doing, whether they were thinking about something else, and how they felt on a scale of zero to 100, bad to good. Subjects queried while having sex averaged 90 on that scale, and only 10 percent of them had their minds on anything else. But when they were pursuing most other activities, the subjects’ minds were apt to stray; 65 percent of those interrupted while engaged in personal grooming, for instance, said they were daydreaming. The study’s most surprising finding is that everyone caught daydreaming expressed the same degree of unhappiness, no matter what they were doing. “The rate of mind-wandering is lower for more enjoyable activities, but when people wander they are just as likely to wander toward negative thoughts,” co-author Matthew Killingsworth tells The New York Times. The best predictor of happiness at any given moment, it appears, isn’t what you’re doing, but whether you’re fully engaged in doing it. And, according to the study, people’s minds are elsewhere 47 percent of the time.