Bull’s-eye targeted
On the picture in “Galactic bull’s-eye” (SN: 9/24/11, p. 10), I am quite puzzled. Do my eyes deceive me, or is there another bull’s-eye galaxy behind the first, located at the 1 o’clock position?

How is this possible? Are these strange objects magically clustered along some line pointing towards us?
Jeff Brewer, Newton Centre, Mass.

It is peculiar that another ring-galaxy–like object would appear in the background, and in fact the Hubble Heritage Team noted its odd appearance. It’s possible, but not probable, that the object is another Hoag-like object. There could also be material obscuring the view of the rest of the galaxy, hiding its true shape. Either way, there’s no sign of ring galaxies being aligned in the sky. The astronomer who created the image wrote a detailed article on Hoag’s Object and other ring galaxies, available at bit.ly/ringgal. As he explains, there’s a diversity of ring galaxies across the cosmos. — Camille M. Carlisle

The upside of stress
Regarding the article “Early stress can be contagious” (SN: 9/24/11, p. 14), I never thought of birds being stressed out, but I suppose they could be singing sad songs. I agree that two people from stressed backgrounds is not a good match. But I think everyone’s childhood is dosed with some difficulties; isn’t it how we learn and grow? If every stressless person married another stressless person, and they produced stressless offspring, it might generate a rather smug society.
Margy Friedland, Manitowoc, Wis.

Early bird on dinosaurs
“Dinosaur-era feathers sealed in amber” (SN: 10/8/11, p. 5) mentions “the notion, first proposed in 1868, that modern birds evolved from … theropod dinosaurs.” Who was the prescient individual who proposed this notion only nine years after the publication of Origin of Species, and where can I find something by or about him?
William Check, Evanston, Ill.

That would be English zoologist Thomas Henry Huxley. Modern paleontologists cite two Huxley papers, published in 1868 and 1870, as proposing that birds originated from dinosaurs. — Susan Milius

Cancer treatment questioned
I read the article “Tumor tell-all”
(SN: 9/24/11, p. 18) with interest, as I’ve always believed that cancer is unique in each individual. The case study of the 78-year-old man with a rare tumor and huge genetic flaws who was given multiple courses of drugs that initially shrunk the tumors but ultimately led to more mutations was especially disturbing. The researcher’s speculation that “only a carefully concocted cocktail of drugs would have stopped the cancer” seems horribly flawed. If genetic mutations equal cancer and genetic mutations plus drugs equal more genetic mutations, then logically cancer plus drugs equals more cancer. Perhaps the answer lies is discovering the underlying causes of the mutations and stopping them using the body’s ability to heal itself.
Althea Greaney, Simsbury, Conn.

The drugs didn’t cause the man’s additional mutations. Cancer mutates rapidly, and the changes probably would have arisen regardless of treatment. The drugs, by halting or slowing growth of some cancer cells, may have left room for small groups of already mutated or newly mutated cells to take over the
tumor. A drug cocktail might have fought many different mutations. It would be nice to correct the underlying mutations responsible for tumors, but gene therapy for cancer is not yet practical. Identifying genetic risk factors may eventually lead to better cancer-prevention strategies. — Tina Hesman Saey

Thanks for rationality
I am a longtime subscriber, and I just wanted to send my special thanks to your editor in chief for his excellent editorial “Communicating science encourages cooperation” (SN: 7/30/11, p. 2). For some time, I have been compiling quotations that speak to the rational side of humans. The following paragraph in the editorial eloquently states the case: “Unified by the common language of mathematics and the unwavering lawfulness of natural phenomena, scientific findings transcend the cultural divides that typically permeate politics, religion, social mores and national customs. Everyone on Earth shares the same physics, the same biology, the same chemistry and the same planet. Scientific knowledge provides the common ground needed for the peoples of the world to live peacefully together. At least it could in principle.”
Richard Holford, Denville, N.J.