Letters to the Editor

19151

While reading your article regarding the primitive antibodies found in lancelets, it occurred to me that complex immune systems might be merely a highly specialized, evolved form of digestion. Presumably, evolutionary adaptation would tend to favor a critter that found a way to consume even those nasty, yucky, infectious microbes. Mel ZernowColusa, Calif.

19150

Your article reports that only two category 5 storms have hit our coastlines. We here in southern New England know that the “Hurricane of 1938” should be counted, too. The indirect evidence of the storm’s power is compelling. The only wind instrument, over 50 miles from landfall, recorded a gust of 189 miles per hour […]

19030

Although we seldom have the deep and persistent snowfields needed to support watermelon snow in the spring, I did note it a couple of springs ago in persistent snowdrifts in and near tree shelterbelts in the high plains of northwest Kansas. One must be cautious of red snow in this area, however, because we occasionally […]

19196

The article claims that Lake Agassiz became the world’s largest lake. It seems to me that the same conditions should have occurred in Asia. Shouldn’t you compare Lake Agassiz to glacier-dam-produced lakes in Asia and contemporary freshwater versions of the Black Sea and the Caspian Sea? Robert W. DavisMillburn, N.J. According to Martin Jakobsson of […]

19195

This article says that women taking some kinds of over-the-counter painkillers are more likely than others to have high blood pressure. The conclusion that the painkiller “boosts their chance of developing high blood pressure,” however, is unfounded. It’s also plausible that whatever causes the women to take the pain medication raises blood pressure. Geoffrey A. […]

19149

It was with great interest that I read this article. I realize that such articles aren’t comprehensive reviews of the literature, but I must point out that we have recently published in Virus Genes direct experimental evidence that supports the involvement of endogenous retrovirus in embryo implantation. Luis P. Villarreal University of California Irvine, Calif.

19189

I feel the need to comment on the misconception that trisomies of other than chromosome 21 don’t survive birth. I have a friend whose daughter is a trisomy 18 and just celebrated her 19th birthday and other friends whose children with trisomies are nearing their teenage years. My own son, a trisomy 13, lived for […]

19148

Newton derived theories about gravity by studying stationary or very slowly moving objects. Laboratory measures of G performed since share this fundamental approach. While this may accurately measure G, any possible relative velocity dependence to this constant or to the force of gravity goes undetected. Determining that force involves only the masses, the separation, and […]

19188

Your article perpetuates a common error regarding pond aquaculture when it states, “These systems all rely on large volumes of clean water flowing to the fish and carrying waste away.” In the catfish industry (the largest pond-culture venture in the United States), ponds are only emptied for renovation once every 10 to 20 years, and […]

19187

After reading this article, I may have an answer for why a routine chest X ray indicated prominent scar tissue on my lungs even though I have never been a smoker during my 61 years. For the past 15 years, since a heart attack, I have jogged or ridden a bicycle for approximately an hour […]

19147

I am concerned about this article. It addresses the mass of fissile materials needed to “make a bomb,” yet it’s clear that the critical masses given–10 kilograms for plutonium-239, 50 kg for uranium-235, and 60 kg for neptunium-237–are for bare spheres with no neutron moderation, reflection, or other factors contributing to going critical. Consider that […]

19186

In your article, a spinning coin’s motion is explained by the existence of an air cushion between coin and tabletop. If this is indeed the case, then I would expect coins to do something quite different in a vacuum. What do they do? Richard Chambers Charlotte, N.C. H. Keith Moffatt offers an explanation for the […]