PRESUMABLY tired of complaints from passengers and watchdog groups, America's Department of Homeland Security (DHS) has agreed to review the safety of the full-body scanners that have become common at many American airports. The Los Angeles Times reported on Thursday that DHS will pay the National Academy of Sciences to review existing research on the safety of the devices—conducting a study of studies, essentially. 

"While [America's Transportation Security Administration, the division of DHS charged with airport security] has told the public that the amount of radiation emitted from these machines is small, passengers and some scientific experts have raised questions about the impact of repeated exposure to this radiation," said Susan Collins, a senator from Maine, last week. There's no timeline for the completion of the review, but you should not expect it to find significant health risks from the scanners—previous studies have not, and that's all this new survey is due to examine.

In other airline-related research news, our sister blog Babbage reports that Boeing, the American aircraft-maker, has been using sacks of potatoes to figure out how to improve in-flight Wi-Fi on its planes. Here's why:

HUMAN beings are bags of brine. This presents a problem for wireless communications, because the range of most commonly used radio frequencies lose signal strength when passing through salt water, as well as through masses of fat, muscle and bone. In large public spaces, like an open area at an airport terminal, human bodies are spread out and have little effect compared to the building materials that enclose the space, like metal and sheet rock. Even in a house, brick and chicken wire are much worse than people in reducing the range of a network. But on an aircraft, even a partially filled cabin provides lots of opportunities for wireless signals to be sucked into folds of flesh.


Human bodies exhibit the dielectric effect, acting as a strong insulator for electromagnetic fields passing through them, such as wireless networking transmissions. The mix of water and salts in a human body are particularly good at attenuating signals in the separate 2.4GHz and 5.0GHz ranges used for Wi-Fi networks worldwide. Potatoes, it turns out, affect the a Wi-Fi signal in much the same way people do.

No word yet on how the potatoes felt about the whole thing. Anyway, read the whole post.