Health & Science

Why Phelps set so many records

At this year’s Olympics, swimmers set 25 new international speed records, compared with only eight new record times at the 2004 Games in Athens. The talents of Michael Phelps and the other record-breakers are partly responsible, but the depth of the pool in Beijing played a major part in the eye-opening speed of the 2008 Olympics’ swimmers, says New Scientist. It’s a matter of basic physics. The Beijing pool is about 3 feet deeper than pools used at earlier Olympics. That additional depth reduces the drag on a swimmer’s body by extending the distance traveled by the so-called bow wave—the wave that shoots downward and outward from the swimmer’s upper body. A swimmer generates a second wave, known as the stem wave, with his lower body. If the bow wave bounces off the bottom of the pool and comes back to contact the stem wave, the result is drag. Since the Beijing pool is too deep for the bow wave to reflect back on the stem wave, swimmers do not have to contend with some of the usual backward pull, enabling them to swim faster. Experts stress, though, that the pool is within official size limits, so the swimmers fully deserve to be in the record books. “The current spate of swimming records is fair and valid,” says exercise scientist Brent Rushall.

Making blood drives passé

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Scientists have devised a method to generate a virtually endless supply of blood from embryonic stem cells, says the Los Angeles Times. The advance could eventually pave the way for a blood supply that comes from the lab, as opposed to from human donors, making blood shortages a thing of the past. “We literally generated whole tubes [of blood] in the lab, from scratch,” says lead researcher Robert Lanza. Scientists used a complex, four-step process that turned the stem cells into red blood cells capable of carrying as much oxygen as normal blood. If the system can be duplicated on a large scale and in a cost-effective manner, hospitals and blood banks will have access to an ample supply of blood of all types, including the rare AB-negative and the “universal” donor type, O-negative. Any use of stem cells harvested from embryos is highly controversial, but researchers say that in this case, the harvesting need only be done once. “The beautiful thing is that you start with one line, expand them indefinitely, and generate as many as you want,” Lanza says.

A jump in measles cases

Measles cases in the U.S. are at their highest level in more than decade, largely because a growing number of parents are not getting their kids vaccinated, says USA Today. There have been 131 reported cases of measles so far this year, the Centers for Disease Control and Prevention reported, compared with 42 for all of last year. Doctors blame the trend on parents’ unfounded fears that vaccines may cause autism. Until recently, the measles vaccine had largely eliminated cases of the highly infectious, potentially deadly disease. But some parents are now shunning vaccines because of concerns over a mercury-based preservative once used in some vaccines. Numerous studies have found no evidence that vaccines containing mercury caused autism. More importantly, the preservative no longer is used in vaccines recommended for young children.

The myth of ‘undecided’ voters

Voters who describe themselves as undecided have often taken a position but just don’t know it, a new Italian study suggests. Researchers last year asked 132 residents of Vicencia, Italy, where they stood on an upcoming ballot initiative on expansion of a U.S. military base. At the same time, the subjects were given a computer test on which they had to match positive or negative images with pictures of the base. After the votes were cast, it turned out that most of the supposedly undecided voters who’d had the most negative associations with the base voted against expanding it, while those with the more positive associations voted for it. Researchers concluded that most of the undecideds had in fact made up their minds subconsciously. The findings, researchers tell The New York Times, suggest that people who profess neutrality about an issue are more vulnerable to their inherent biases than they realize.

The face of cultural differences

Culture shapes our perceptions so fundamentally that it could even determine how we look at other people’s faces, says Wired.com. Researchers at the University of Glasgow in the U.K. studied how Europeans and Asians moved their eyes when they looked at portraits, and they discovered stark differences. Asians focused their gaze at the center of faces, while Westerners looked first to the eyes, then to the mouth. Researchers say the differences reflect different attitudes toward individualism and society. Western culture is more individualistic; the approach to facial recognition is piece-by-piece and more intimate. Eastern societies tend to be more collectivist, and facial recognition proceeds in a more holistic manner. It’s actually a matter of debate whether the different styles of facial recognition are a product of the different cultures or a factor in shaping them. “It’s the chicken-and-egg problem,” says researcher Roberto Caldara. “We’re testing children to see whether these effects arise early.”