Letters
By Science News
Impossible view
In “Milky Way puts on weight” (SN: 1/31/09, p. 8), you claim to show an image of the Milky Way. This image cannot be real. Worse, it creates misconceptions: As a college educator, I find that most students actually believe NASA has launched probes outside of the Milky Way to take pictures of our galaxy. I hope that printing a correction will help dispel that belief.
Don McCarthy, Tucson, Ariz.
McCarthy, of the University of Arizona’s Steward Observatory, was one of a number of readers who pointed out the impossibility of taking a “real” image of the entire Milky Way galaxy, the subject of the art in the January 31 issue. As reader William Westervelt of East Granby, Conn., put it: “How can we get a plain view of an entity that we are all mixed up with, in the middle of?” To clarify, the image shown is an illustration based on an animation called “Virtual Voyage through the Milky Way” from the Chandra X-ray Observatory website. We did not mean to imply that this was an actual photo. —Eva Emerson
Inspired by change
The editor’s statement (“For both universe and life, only constant is change,” SN: 2/14/09, p. 2) that change is the only constant is a factual idea one encounters infrequently. I was teaching my students this in 1956, spurred by Marcus Aurelius’ Thoughts. He made the point in several places in his writings, though he may not have been the earliest to do so. Early on, I raised the ire of biblical fundies in East Texas and beyond, but I continue to believe and express that change is the only real constant. Thanks for your editorial. The emperor would have loved it!
Franklin H. Mason, Tyler, Texas