Letters to the editor

Grand Canyon rising
If the geology of the Grand Canyon dates back to 70 million years ago “Grand Canyon’s age pushed back,” (SN: 1/12/13, p. 15), that would be around the same time the Rocky Mountains were being pushed up by the subduction process originating off the western continental coast. Could the lifting of the Colorado Plateau be related to the lifting of the Colorado Rockies?
Joe Flynn, Spanaway, Wash.

The timing of the Colorado Plateau’s uplift remains fairly controversial, including whether it occurred all at once or in several discrete stages. But many geologists think it may have been at least partially related to the same event (known as the Laramide orogeny) that raised the Rocky Mountains between about 70 million and 40 million years ago. — Alexandra Witze

Seeing clearly
Regarding your article on the surge of nearsightedness “Urban Eyes,” (SN: 2/9/13, p. 22): When my mother taught third grade in the early 1930s, teachers were instructed to have their students stop their work on a regular basis and look out the large bank of windows on the north to the distant mountains. She often said that there is nothing new in education; the experts just rediscover the old.
Carolyn Conner, Chula Vista, Calif.

As a teenager in the ’60s, I saw an article on submarines mentioning that men on sub duty become nearsighted (irreversibly, it was thought). The thinking was that living weeks at a time with nothing more than six feet away was to blame. 
Simon G. LePorte, Hanson, Mass.

A 1983 report from the U.S. Naval Submarine Medical Research Laboratory in Connecticut cited French research showing some visual discomfort among submariners. Shortly after returning from sea, some reported they “could not see as well as usual” and had problems driving at night, the study found. But no abnormalities were found in their eyesight two weeks later. The report also cited a study of 18 men kept indoors for 45 days who showed changes in eyesight toward myopia, mainly in men who were already nearsighted or farsighted. But these also normalized after two weeks of outdoor light exposure. — Nathan Seppa

Going between sun and shade exercises iris muscles; looking from flower to bird in tree to clouds exercises lens muscles. Exercise improves muscle fitness, helping to maintain normal vision. As in all muscles, use it or lose it. 
Patricia Thomas, Streator, Ill.   

New Silicon Valley
I enjoyed Alexandra Witze’s article on synthetic biology “Factory of Life,” (SN: 1/12/13, p. 22), but it left something out. Clearly, that area of the country now needs its own nickname, a la Silicon Valley. I propose that it be called Carbon Harbor, which sounds especially good with a Boston accent.
Drew Massey, Sherman Oaks, Calif.
 
As someone whose father hails from Providence and talks about pahking the cah in Hahvahd Yahd, I think this reader is onto something. — Alexandra Witze

Women’s sports sociology
I believe the middle female football player in the “girls on the gridiron” photo “Tackling women’s pro football,” (SN: 2/9/13, p. 32) is my mother, the former Alice Holmberg, who graduated from Gustavus Adolphus College in 1927. My mother said the whole thing was mostly a lark, as none of the girls knew anything about football. In her defense, I should mention that my mother was quite an accomplished athlete in other sports. She is memorialized in the Gustavus Adolphus athletic hall of fame for her basketball skills. Thanks for taking me down memory lane.
Jack Meyer, via e-mail