If Joel Brind ["The Scientist Who Hated Abortion," February] wants to convince people of the relationship between abortion and breast cancer, many more questions need to be answered. If the basis for his concern is the hypothesis that proliferating breast tissue prevented from maturing into milk-producing cells renders the gland susceptible to cancer, then questions regarding a similar risk should be raised for women who miscarry. There is also no mention of whether a completed pregnancy ameliorates this connection. Aside from the abortion issue, Brind could have done a much better job of researching the related issues. Credibility is strained when it is tied to an agenda.
A. Lee Spearfish, South Dakota
In Sky Lights [February], Bob Berman defines the strong anthropic principle: "The universe must have properties that allow life to develop because it was designed to generate observers. John Wheeler, the physicist who coined the term 'black hole,' has long supported this view." However, if Berman were to read August 2002's Letters page, he would find this clearly worded denial from Wheeler himself: "The process whereby the macroscopic world reacts to a quantum event— the process that makes reality— can, in my view, be accomplished with inanimate matter. Following Niels Bohr, I like to call this process 'registration' rather than observation (which too strongly suggests human involvement)." Berman then states that many scientists gingerly embrace the weak anthropic principle. As presented by Berman, the weak anthropic principle is an obvious truism: The conditions of the universe, present and past, are compatible with our current existence. Why then would anyone be hesitant about his acceptance of the weak principle?
David J. Schuller Ithaca, New York
Bob Berman responds: I confess— the statement about Wheeler's position regarding the strong anthropic principle is an oversimplification of his philosophy. On the other hand, Wheeler's participatory universe does set aside a special role for a conscious observer— something that is obviously not possible in a universe that does not lead to the existence of conscious beings. One of my column's goals was to bring up a principle that most astronomers accept and also to present the critic's assertion that it's actually little more than a piece of circular reasoning: The universe is extremely odd and unlikely, it had to be that way for us to be here making that observation, and therefore it's not really odd after all.
This Space for Rent
GPS-based hypertext sounds wonderful in theory [Emerging Technology, February], but I have to ask: Who "owns" the message space around a restaurant? The owner of the establishment, the competition, or the National Restaurant Association, advocating for all? The reviewer who offers paid criticism, the casual visitor, or the passerby who wants to post something unrelated? The anarchist wanting to deface the message, or the hacker wanting to erase it? The spammer hawking a life-enhancing pill, or the scammer with a get-rich-quick scheme? And where are the boundaries? Too narrow and you might miss a message as you pass by; too broad and one message may preclude another. E-mail was great in theory, too, until the spammers took over. GPS hypertext could have a future exactly as envisioned by your writer. Unfortunately, by analogy, I see the whole thing turning into another piece of background noise.
Dan Pernokis Sault Sainte Marie, Ontario
When Dinosaurs Fly
Two issues bother me in regard to evolutionary biologist Alan Feduccia's opposition to the idea that birds are directly descended from theropod dinosaurs [Discover Dialogue, R & D, February]. How does he reconcile his statement "Evolving flight from the ground up is biophysically implausible" with the evolvement of bats? Second, if he dismisses so-called proto-feathers as cosmetic similarities, how does he explain why lizards, who lived through the age of the dinosaur and are here today, never developed any of these traits?
Janet Furcello Mayfield Heights, Ohio
Alan Feduccia responds: Charles Darwin (1859) was probably the first to propose a trees-down theory for the origin of bat flight. Every group of vertebrates has evolved some form of flight, from parachuting to gliding, or even powered flight, and in all cases flight originated from the trees down. If birds are derived from dinosaurs, and dinosaurs have feathers, that's fine, but we must be careful to leave out secondarily flightless birds with feathers (like ostriches) that only superficially resemble dinosaurs. There are Cretaceous archosaurs with true feathers, and there are others displaying a halo of filaments. Determining the identity of the latter should be accomplished independently of the identity of the specimens. As the science now stands, since "birds are dinosaurs," it therefore follows that any skin filaments are proto-feathers!
I Love Radiation
"Is Radiation Good for You?" [December], which reported on the beneficial effects of low-dose radiation, was excellent. I'm the 81-year-old guy referred to in the article as the only patient treated with the low-dose radiation procedure— only now I'm 85. I still have a malignancy of the bone marrow that causes the blood to become more viscous by the production of excessive nonfunctional antibody molecules. Over three years ago I started a search for a radiation oncologist to treat me with low-dose radiation. I was turned down by a half dozen before I made contact with James Welsh (now at the University of Wisconsin at Madison). Within five weeks, my blood viscosity was down to acceptable levels. With chemotherapy, it took about six months to attain the same benefits. As the article states, I relapsed later. However, 12 years after my diagnosis, I am still fit, relatively asymptomatic, and suffering no adverse effects from the radiotherapy. My experience indicates that this treatment clearly warrants further exploration.
Edward J. Bauser Naples, Florida
Pavlof ("Season of Fire," February) is North America's most active volcano. Hawaii's Kilauea is the most active volcano in the United States.