Letters from the September 16, 2006, issue of Science News

Hot topic

It seems more likely that a decline of total precipitation and humidity would be the direct cause of both temperature and fire incidence (“The Long Burn: Warming drove recent upswing in wildfires,” SN: 7/8/06, p. 19). It is fashionable to blame every weather problem on greenhouse gases and global warming, but in this case doing so may lead to false conclusions.

Paul Bade
Mankato, Minn.

Neither the study nor our story attributed the regional warming since 1970 to global warming. The study did find that spring and summer temperatures correlated with decreases in precipitation.—B. Harder

Short shrift to sea sheer

As a malacologist, I enjoyed “Shells may represent oldest known beads” (SN: 7/8/06, p. 30). Although the holes look like what could be made with a stone tool, the Science paper acknowledged that a small percentage of naturally occurring holes look similar. Either the people deliberately selected shells with suitable holes or else they perforated them deliberately. Both options show effort at obtaining decorative objects.

David Campbell
Tuscaloosa, Ala.

A penetrating look

When discussing how polarized light can help clarify our understanding of supernova mechanisms, “Astronomy Gets Polarized” (SN: 7/8/06, p. 24) initially quotes Doug Leonard’s explanation that “one does not see deeper into an object using polarimetry.” Later, the story says that “polarization studies viewed deeper and deeper layers of the explosion.” Which is it?

Hal Heaton
Damascus, Md.

Polarization studies don’t provide a more penetrating view in the way that a radio wave or infrared detector can peer through dust. Rather, as dust around a supernova thins, the amount of polarized light can tell you the shape of the exploded star.—R. Cowen

Stupid-human tricks

On “Live Prey for Dummies: Meerkats coach pups on hunting” (SN: 7/15/06,

p. 36), real cats do this too. I have observed many adult cats teaching kittens (not necessarily theirs) to hunt. People who receive “presents” from their cats are not being gifted. The cats are trying to teach them how to hunt, but the cats probably think we are pretty dumb.

Emily Johnston
Westminster, Md.