Galactic collisions explained Perhaps you can explain why Andromeda and the Milky Way are going to collide “Milky Way will be hit head-on,” (SN: 7/14/12, p. 10). Galaxies, as is always written, are rushing away from each other at ever-increasing speeds. How do things collide when there is never anything to collide with? Either galaxies are rushing outward in all directions with the same impetus from the point of the Big Bang, or they are not. Bruce Smith, via e-mail Galaxies do indeed collide with one another even though the universe is expanding at an ever-accelerating rate. I... (p. 4)

Shopping standards shift with age In “When good moods go decisively bad” (SN: 6/16/12, p. 10), researchers assume that their 70-year-old study participants would be as interested as their 20-something counterparts in finding up to 40 prices on 60 products in an Internet shopping exercise. When the septuagenarians fail to choose the cheapest product, the researchers infer that the happy elderly may make poor decisions. Perhaps instead, the happy oldsters make a quick, acceptable decision rather than waste time making a marginally more perfect one. Kevin Stevenson, Port Townsend, Wash... (p. 31)

Redesigning flu mortality In “Designer flu” (SN: 6/2/12, p. 20), researcher Michael Osterholmis quoted as saying that even if the actual kill rate of H5N1 is 20 times lower than the current estimate of 59 percent, H5N1 would still have a mortality rate that “far exceeds” that of the 1918 flu. Wikipedia gives a 1918 flu infection rate estimate of 27 percent, with 3 percent of the world’s population dying. Using the 3 percent mortality rate, “20 times lower” would require an assumption that the H5N1 infection rate is 100 percent, so the phrase “far exceeds” would require an ... (p. 30)

Statins oversold The article that extols statins’ purported benefits for conditions ranging from infection to cancer (“Another side to statins,” SN: 5/5/12, p. 30) does not reflect the balance of evidence. Both favorable and adverse mechanisms apply. We regularly hear from patients who have suffered serious adverse effects, for whom data had not supported expectation of net benefit with statin use but who were prescribed statins by exuberant physicians influenced by the promise of benefits extolled in worshipful, imbalanced (if well-intentioned) articles like this. Beatrice A. Gol... (p. 31)

Dark matter inspiration On reading Tom Siegfried’s editorial “Dark matter nothing to fear, if it’s there or not” (SN: 5/19/12, p. 2): As into the universe I did stare      I met a particle that wasn’t there      It wasn’t there again today      Oh, I wish it would go away. Tom Derderian, Winthrop, Mass. Reality bits Regarding “Bits of reality” (SN: 4/7/12, p. 26): There may be a catch in the hypothesis that the rules of information processing determine physical theory. This idea appears to be base... (p. 31)

Information as substrate In a recent article (“Enriched with information,” SN: 3/10/12, p. 22), you point out that some researchers consider consciousness to be a form of information. In another (“Bits of reality,” SN: 4/7/12, p. 26), you mention that increasing numbers of physicists are coming to regard information as the basic “stuff” from which our universe is made. Information as the substrate of consciousness, information as the substrate of the material universe. An interesting connection, to say the least. Ed Subitzky, New York, N.Y. Still learning from Science... (p. 31)

Visions spark debate In “Visions for all” (SN: 4/7/12, p. 22), researchers found that functioning people who “hallucinated” God were high on the “absorption” scale and that 4 percent of people studied reported hallucinations. This reminded me that 4 percent of the population is grade V hypnotizable. All of these superhypnotizable people rate very high on absorption. [As a psychiatrist,] I had patients like this who had been severely abused as children. These are the ones who developed multiple personalities, or dissociative identity disorder. These patients often had visions of... (p. 31)

Happy 90th, Science News My father has generously given a subscription of Science News to me since I was small. In the ’60s I received a package in the mail each month containing science experiment materials and directions. So cool! We celebrated Dad’s 90th birthday in April. He was an aeronautic engineer; I’m an architect. I am sure the magazine you deliver to us each month gives us the same joy. Thank you for making Science News a joy for so many of us for so many decades. Becky Thompson, South Pasadena, Calif. I’ll add to what has probably been a flood of congratulations for... (p. 35)

Consciousness series pondered Hofstadter’s “strange loop” and other ideas presented in the article “Self as symbol” (SN: 2/11/12, p. 28) suggest, but never say, that the notion of “I” exists in the dimension of time, not space. Obviously then, consciousness is not a tangible object — not any part of the brain. Rather, the “I” phenomenon is a process, a happening, always actualized with verbs like think, remember and exist. This idea is evident when one considers that self-awareness is always “now,” carried along the arrow of time. Just as movie cels projected in sequ... (p. 31)

A Boy Scout’s salute I am a Boy Scout doing the Communications Merit Badge. I am supposed to write to the editor of a magazine and express my opinion.I’ve always loved the Atom & Cosmos section because I’m very interested in particle physics and on the other end of the scale, cosmology. “Earth-y orb found in habitable zone” (SN: 3/10/12, p. 14) describes a planet 22 light-years away from Earth that could potentially have life on it. It really is fascinating to think that there are other civilizations out there in space all searching for other forms of life.Another topic that I... (p. 31)