Time’s arrow I’ve enjoyed reading Science News since I was a kid; thanks very much for producing such a fine periodical! This is the first time I’ve felt compelled to write to you about an article you’ve published: “Law and disorder” (SN: 6/19/10, p. 26). I can’t help but feel that the time theory that Sean Carroll proposes misses the point of time. Time is the observation of forces acting on matter or energy. Take an event such as dropping a ball: Gravity acts on the ball, pulling it to the ground. If we reverse time, the ball will be repelled from the Earth. The ball ... (p. 34)

A placebo’s true nature There is a serious misconception put forth in the letter from William Davis (Feedback, SN: 5/22/10, p. 31). The placebos used for placebo-controlled, double-blind studies of pharmaceuticals are not “sugar pills.” These placebos are made from the same inactive ingredients in the same proportions used to make the dosage form containing the drug under study. These inactive ingredients seldom include sugar(s). These are the ingredients that make the dosage form easy to handle (fillers), hold together as tablets (binders), dissolve quickly in the stomach (d... (p. 31)

Engineering irritation The article “Engineering a cooler Earth” (SN: 6/5/10, p. 16) was incredibly irritating. The solution to global warming is not technology of the type presented, but population and pollution control. You need to start talking about that. The longer we see the problem in technical terms, the less likely we are to even talk about the real solutions. (How many articles have you had recently discussing limiting population — that’s science, isn’t it?) Suppose we dump a bunch of chemicals in the biosphere and it cuts global temperatures a bit or holds them s... (p. 31)

SN on the newsstand I’m blind so I’ve been reading your magazine in braille for quite a while. But most of my sighted friends have never heard of you guys. This is a great publication, and I’m glad that more readers will now become familiar with it (“Science News goes public: available on newsstands,” SN: 5/22/10, p. 2). Rick Lovecchio, Doraville, Ga. We hope so too. Select bookstores across the country now stock Science News. To find out how to order the braille edition, contact the National Library Service for the Blind and Physically Handicapped at www.loc.gov/... (p. 31)

Call for caution “Bar codes may check out next” (SN: 4/24/10, p. 14) describes a new ink that would enable a full grocery cart to be quickly checked out electronically. Hurrah? Undoubtedly the amount of radio frequency per package would be minimal. However, if much of our food were handled that way, and people used it for years, the exposure might be significant. What would be the effect on our health and the environment? We thought plastics were wonderful; they are, but are now in our blood and mothers’ milk. Flame retardants have their own litany of problems, including, ... (p. 31)

ET, stay home Your excellent editorial in the April 24 issue of Science News (“An intelligent ET would probably just stay home”) explained the most obvious reasons for the unlikelihood of an extraterrestrial message, let alone visitors. Additional obstacles worth mention are 1) the gigantic retro-rockets, parachutes and heat shields required for braking a super-speeding vehicle, and 2) the galactic power needed for aligning the astronomical egos of spaceship builders, launchers and captains. Curtis L. Brown, Neenah, Wis. Reading Tom Siegfried’s column on extrater... (p. 30)

Making morphine The article “Chemists pin down poppy’s tricks for producing narcotic painkiller” (SN: 4/10/10, p. 5) may presage geopolitical changes in Afghanistan, regardless of whether there are engineered virus attacks or alternative crop programs. A technological advance like this one will eventually be used in the United States and Europe. Even if governments continue to treat morphine as a controlled substance, producing it domestically will trump the costs and difficulties of smuggling. Terry Franklin, Amherst, Mass. Gut sense I’ve been vindicated (“Stomac... (p. 31)

A statistical education Odds are it’s wrong, but the chances that statistics is to blame are slim and fat. Tom Siegfried (“Odds are, it’s wrong,” SN: 3/27/10, p. 26) accurately portrays the importance of statistics in the conduct of science. However, his failure to clearly distinguish between the misuses of statistics and its methodological limitations leads to misleading conclusions about the role of statistics in the proliferation of erroneous scientific results. Statisticians have long recognized the challenges presented by multiple testing, the interpretation of observation... (p. 32)

Naked speed The article “Running barefoot cushions impact of forces on foot” (SN: 02/27/10, p. 14) says a lot about whether running barefoot is or isn’t healthier than running shod. Has anyone looked into which is faster? Henry Jones, Baton Rouge, La. “No,” responds Daniel Lieberman, a professor of evolutionary biology at Harvard University. But he does note that Abebe Bikila set a world record for the marathon at the 1960 Rome Olympics running barefoot. And Zola Budd set quite a few records running middle distances barefoot. “There is no theoretical reason why ba... (p. 31)

Hairy Ardi issue In the report on Ardi (“Evolution’s bad girl,” SN: 01/16/10, p. 22), the artist’s illustrations show her in fur. The fact that her purported descendants are relatively hairless has been popularized by Desmond Morris (The Naked Ape, 1967) and Elaine Morgan (The Descent of Woman, 1972). What is the paleoanthropologists’ evidence that Ardi had not yet shed her fur coat and gained the advantage of superior heat loss in tireless pursuit of game? Walter J. Freeman, Berkeley, Calif. Hairiness made sense for an early hominid species that lived in forests, had i... (p. 30)

Ancient graffiti Regarding “Graffiti on the walls in Pompeii” (SN: 01/30/10, p. 14), I remember reading some years ago about graffiti being discovered in Pompeii. There was even a symbol that researchers interpreted as a sort of “Kilroy was here.” Is this an on­going study? New sites? I wonder if there were other markings, such as height marks recording children’s growth? The article says “written” — were all of the marks scratched into the rock? Bob Wilson, Oakridge, Ore. Graffiti were first observed at Pompeii in the late 19th century. More than 11,000 insta... (p. 31)

To their credit In Tom Siegfried’s article, “The Top 10 science news stories since time began” (SN: 1/2/10, p. 2), No. 5 is “Watson and Crick elucidate DNA’s double helix structure, 1953.” I am annoyed that, as usual in articles about the early understanding of DNA, Rosalind Franklin’s name has been left off. Even Watson and Crick admitted that without her work they could not have been successful. Ted Coskey, Seattle, Wash. Tom Siegfried’s list of the Top 10 “science news favorites from the dawn of civilization” includes the comment that “analyses of new s... (p. 30)

Snack addicts The experiment outlined in “Junk food turns rats into addicts” (SN: 11/21/09, p. 8) seems to have overlooked an ingredient list. The junk foods fed to the rats were junky, to be sure, but which foods were the most addictive? Many junk foods are filled with alarming amounts of things like mono­sodium glutamate. Were the rats more responsive to the MSG-laden foods? Did they crave salt over sugar? Fat over starch? This article left me hungry for specifics. Drew Massey, Los Angeles, Calif. In the study, researchers fed the rats a mishmash of junky foods (th... (p. 28)

Thinking animals An interesting article, but the question of human consciousness seems no closer to solution in “Humans wonder, anybody home?” by Susan Gaidos (SN: 12/19/09, p. 22) than it did in Julian Jaynes’ The Origin of Consciousness in the Breakdown of the Bicameral Mind of 1976. It seems to me that all the mental abilities discussed do not show that humans can do something unique to our species, or show that we are more “conscious” than other species, but only that species display varying degrees of ability. For example, humans are not the only animals to make tools, ... (p. 31)

Well-tooled apes The fascinating article “Aping the Stone Age” (SN: 11/21/09, p. 24) led me to wonder whether researchers who work with chimps or other higher apes have ever introduced them to the modern tools used by humans, such as saws, axes, hammers or pliers. If so, it would be interesting to know whether the apes could grasp the tools’ purposes, employ them productively and/or demonstrate their utility to ape kin. Jack J. Friedman, Fort Lauderdale, Fla. Andrew Whiten of the University of St. Andrews in Scotland replies: An interesting question. Some studies have... (p. 31)