Outsized beaver
Accompanying your recent article about giant extinct beavers (“Ancient beavers did not eat trees,” SN: 11/21/09, p. 10), there is an illustration that seems to show that the extinct beaver was about twice the length of a present-day beaver. I measured each from nose to the base of the tail rather than to the tip of the tail since the tails seemed so dissimilar. This suggests to me that the ancient beaver would have had close to eight times the mass of the present-day beaver, since width and height would likely also be doubled, yet the article describes an ancient beaver of up to 100 kilograms, which is only about three times the mass of large, present-day beavers. Is the illustration out of whack, or did “twice the size” in the caption mean “twice the length?”
Greg Skala, Nanaimo, Canada

You’re right. Although the beavers shown in the schematic diagram correctly show the different shapes of the animals, including the giant beaver’s otterlike tail, they were drawn slightly out of proportion, which is why your mass estimate was high. — Sid Perkins

Uncloaked appreciation
I thought the cover and the follow-up artwork for the invisibility-cloaking article (“Invisibility uncloaked,” SN: 11/21/09, p. 18) were excellent. By chance, I am familiar with that invisible guy. He is an occasional uninvited guest to my house where he moves things I have put away so that I cannot find them. Are you at Science News missing things from time to time? Do you suppose he knows anything about a large quantity of missing matter?
Mac Walker, Madison, Conn.

The article “Invisibility uncloaked” was fascinating. What is even more fascinating is that the cloaking phenomenon where the protagonist is completely hidden but cannot see out — no light — was described exactly in fantasy novels by L.E. Modesitt Jr. in the 1990s, years before Leonhardt’s first attempt at publishing his paper in Nature. Either the author was prescient or had access to earlier work on the subject.
Robert Graf, Capitola, Calif.

Climate brouhaha
I feel compelled to write a comment in reference to Janet Raloff’s article on climate politics (“Climate might be right for a deal,” SN: 12/5/09, p. 16). I just wanted to say that I am eagerly awaiting her follow-up article regarding the revelation of data manipulation and destruction, the subordination of the peer-review process and overall unethical and unprofessional behavior of leading climatologists and other global warming advocates. Notice that “global warming” has now been replaced by “climate change”? Whoever the person(s) are that revealed such behavior and viewpoints in the e-mail, they have given the science community a chance to redeem themselves. I hope Science News will help.
James L. Fowler, via e-mail

Several readers have questioned why Science News has not covered the unauthorized release of e-mails related to climate change. The short answer is that there was no new science to report. An exhaustive review of the e-mails by the Associated Press concluded that “the exchanges don’t undercut the vast body of evidence showing the world is warming because of man-made greenhouse gas emissions.” The e-mails (as reported in Raloff’s Science & the Public blog, “‘Climate-gate’: Beyond the embarrassment,” SN Online: 12/12/09) revealed some intemperate language and bad behavior, but scientists’ personal shortcomings do not change the chemistry and physics of the atmosphere: The vibration frequencies of carbon dioxide molecules remain the same, and the measurements of carbon dioxide concentrations in the air have not been rescinded. The basic science underlying concerns about climate change has repeatedly been verified by various observations and measurements, experiments and theoretical analyses. Many uncertainties remain, but assertions that the world’s leading atmospheric scientists are perpetrating a hoax or conspiracy are without scientific merit, and Science News will continue to report on the science of climate change and its societal implications. — Tom Siegfried

Population issues
Many kudos to David Attenborough (“Scientific Observations,” SN: 11/7/09, p. 4) for speaking out about the overpopulation crisis, which is far more dangerous, threatening and immediate than global warming or which nation has nuclear weapons. No world leader has it as an urgent priority, as far as I know. We are like people with a wild elephant in the living room that we choose not to notice.
Ken McMillan, St. Augustine, Fla.

Enjoyed the read
A hearty thank you and kudos to Susan Milius for her well-written article on seagrass and its niche in the marine environment (“Botanical whales,” SN: 12/5/09, p. 22). Her piece was informative and also delightful to read. I got the feeling that she really enjoyed her trip on the government vessel Nancy Foster to the Dry Tortugas off Florida’s west coast, though she suffered some trepidation as a landlubbing reporter. Milius explained the ecology of seagrass, how it evolved from land-based life and how it contributes to robust coasts, and did so with picturesque language (e.g. “seagrass expanses are shrinking under the human bootprint”) and simple analogies, easy to understand. I began to feel a touch of envy for all those NOAA researchers on board, stationed at Beaufort, N.C., making a living in such an Edenic setting and furthering the scientific enterprise of understanding our world. The aerial photo of Garden Key isle with Fort Jefferson is breathtaking. Keep up the good work.

Paul Rizzuto , via e-mail