Letters from the February 19, 2005, issue of Science News

Negative thinking

The article “Sweet Glow: Nanotube sensor brightens path to glucose detection” (SN: 1/1/05, p. 3) mentions “ferricyanide, an electron-hungry molecule.” This puzzled me no end. Aren’t ferricyanide molecules, unlike their ions, electrically neutral? I’m trying to visualize ravenous molecules gobbling up innocent electrons.

Ernest Nussbaum
Bethesda, Md.

Ferricyanide is indeed an ion, with a negative charge of –3. It’s electron hungry because, counterintuitively, it draws an electron from the carbon nanotube to become ferrocyanide (charge of –4). The reaction tends in that direction because ferrocyanide is more stable thermodynamically than ferricyanide is.—A. Goho

Meltdown

“Alpine glaciers on a hasty retreat” (SN: 1/1/05, p. 13) reports that between 1973 and 1999, “the total area covered by almost 940 Swiss glaciers fell by 18 percent, an average rate of 1.3 percent per year.” An 18 percent loss over 26 years represents an annual rate of less than 0.8 percent. An annual loss of 1.3 percent would mean a total loss over 26 years of almost 29 percent.

Mark W. Budwig
New York, N.Y.

The 18 percent figure is correct for the period from 1973 to 1999. The 1.3 percent annual figure was for the period from 1985 to 1999.—S. Perkins

Alien notion

I wonder if the upsurge in alien, invasive species in real estate boom areas (“Plants: Importance of being economic,” SN: 1/8/05, p. 30) is, at least in part, because of careless gardening. Many people introduce non-native plants into their landscape without regard to the potential for domination of these pretty plants over native species.

Carol Senske
Green Lane, Pa.

Legends in their own words

In light of the findings reported in “Temples of Boom: Ancient Hawaiians took fast road to statehood” (SN: 1/8/05, p. 20), it seems obvious that there’s a need for anthropologists to revisit the records of local “legends” as they study human development in any area. Doesn’t it seem absurd that anyone studying human history would discard actual reports from humans about their own history?

Elizabeth Bollt
Potsdam, N.Y.