Web edition: September 25, 2007
Print edition: September 29, 2007; Vol.172 #13 (p. 207)

Questioning the surge

"The Power of Induction" (SN: 7/21/07, p. 40) was written as if this was a newly discovered technology. I have been using an electric shaver with induction recharging for years.

Mike York
Phoenix, Ariz.

The ability to project electrical power some distance suggests a possible method to detonate or disable improvised explosive devices.

Josef Heit
Webster, N.Y.

Several readers pointed out that wireless induction already powers various devices, such as cochlear implants. However, Aristeidis Karalis of the Massachusetts Institute of Technology (MIT) responds that, to the authors' knowledge, all previous applications used induction at distances not substantially larger than the size of coils involved. Second, the MIT invention could in principle shut down the electronics of a bomb detonator, but at no greater a distance than a few meters.—D. Castelvecchi

Weighty opinions

People don't need another reason to shun fat people ("Weighting for Friends: Obesity spreads in social networks," SN: 7/28/07, p. 51). This group represents the last scapegoat for righteous discrimination in our image-obsessed society. There are myriad reasons a person becomes obese. Friendship is not one of them.

Shawn Dehne
Littleton, Colo.

As such studies progress, it will be interesting to learn if the opposite—weight loss—is also influenced by social networks. And if not, why not.

Victoria D. McCoy
Drake, Colo.

Credit due?

I was surprised to find no mention in "Antidepressants trim suicide tries" (SN: 7/28/07, p. 61) of the possibility that the decline in suicide attempts might be owed merely to the hope generated by beginning a treatment, rather than the treatment itself. I have known depression sufferers to be nearly euphoric after starting a new treatment.

Karen Aiken
San Francisco, Calif.