Thanks for the support As a high school teacher, I have had many students who have heard about the global cooling scare of the 1970s, and these students hold on to those ideas even in the face of overwhelming evidence to suggest that the current warming trend is real. Until I read Sid Perkins’ article “Cooling climate ‘consensus’ of 1970s never was” (SN: 10/25/08, p. 5), I have never had a strong argument to address that concern. There may be only a few global warming critics among scientists, but policy is so often dictated by the court of popular opinion. I am quite glad that Thom...

Two crops, only one pops In “Let’s get vertical” (SN: 10/11/08, p. 16), writer Rachel Ehrenberg reports that “increased demand for a single crop, such as corn, is felt from movie theaters to hog farms.” It is important to note, however, that the corn fed to moviegoers and the corn fed to farm animals aren’t the same thing. In fact, they are two distinct and different varieties. Popcorn is Zea mays averta, a type of flint corn. The corn used as animal feed, called dent corn or field corn, is Zea mays indentata. Try to pop field corn, and you’ll just get hard, tough, hot corn. Je...

Testosterone proxy In the study on the correlation of high levels of serum calcium with fatal prostate cancer (“Cancer-calcium connection,” SN: 9/27/08, p. 12), were testosterone and vitamin D levels also measured simultaneously? Since low levels of both are related to osteoporosis in men, and testosterone is known to be a fuel of cancer, wasn’t perhaps calcium just a proxy for testosterone? Edward Kausel, Cambridge, Mass. Participants were given vitamin D and calcium supplements as part of the study. But the researchers didn’t measure blood levels of vitamin D, and they acknowled...

Readers share their thoughts on "Down with carbon" (SN: 5/10/08, p. 18), which describes carbon dioxide sequestration: Complex schemes The article repeatedly mentions liquid CO2, which has to be under high pressure to become a liquid. Has the CO2 released from burning fuel to run the necessary compressors and pumps been considered, or would those be powered with wind or solar energy? If so, why not just use those sources directly to replace fossil fuels and make less CO2 to begin with? Why keep devising complex technological schemes to fix problems rather than simply avoiding the techno...

Plants and rheumatism Some medical specialists in the field of rheumatology might find it useful to review the work of Ann M. Hirsch and Angie Lee, mentioned in the article by Susan Milius (SN: 4/12/08, p. 235). It describes a process in plant fixation of nitrogen involving biological action that seems to attract calcium. Perhaps a similar action occurs in human bone joints, causing the attraction of calcium in rheumatism. Roger W. Otto, San Mateo, Calif. A pervasive hidden influence “Dad’s Hidden Influence” (SN: 3/29/08, p. 200) states that, “Fathers 40 and older have an increas...