TIME KEEPS ON TICKING
I was intrigued by "Time Machine" [November]. Although the apparent intent of the Clock of the Long Now project is to make us more aware of long-term thought, several comments in the article reflect a misunderstanding of the technical concept of "accuracy." The lead-in paragraph says that the clock is designed to "run with perfect accuracy." The term "accuracy" is a qualitative expression that attempts to describe the degree to which a measurement is "inaccurate." In the field of metrology, this imperfection is best described in statistical terms, the accepted term being "uncertainty of the measurement," or the degree to which the "true" value is not known. Even the NIST-F1 cesium fountain atomic clock is not perfect; it attains an uncertainty level of about 5 x 10–16 second. This is equivalent to about +/– 1 second in 60 million years.
Kurt SolisHouston, Texas
YOU AND ME AGAINST THE WORLD . . . OF MAINSTREAM SCIENCE
In "Two Against the Big Bang" [November], Geoffrey and Margaret Burbidge are victims of the established community of cosmologists, theorists, and astronomers. The Big Bang theory is passionately defended, yet the same defenders fail to be open-minded to new observations and ideas. Ignoring and punishing those who question the Big Bang theory and offer alternatives is bad science. If all observational data are no longer valued, our future is a dim one.
Vance BagwellCedar Hill, Texas
It was highly inappropriate for your writer to flippantly dismiss the Big Bang theory—the result of decades of effort by some of the best scientific minds on the planet—as a "creation myth." You also failed your reporting responsibilities by merely mentioning the cosmic microwave background in passing and by not pressing the Burbidges as to how their theory explains those crucial data. Besides that, you should not have made outdated references to an "infinitely dense point" at the origin of the universe, when the updated origin has the universe's initial size as a small multiple of the Planck length. The temperature and density were certainly "colossal" (as Brian Greene says) but by no means infinite.
P. Brian SchoonmakerFriendswood, Texas
THE DISCUSSION CONTINUES
In commenting on "Darwin's Rottweiler" (Letters, November), Dorothy Sutton praises evolutionist Richard Dawkins's new book, The Ancestor's Tale, but does not mention that in it he has no explanation for the Great Leap Forward. Some 40,000 years ago this "leap" produced culturally modern humans from a population of Homo sapiens that stayed the same anatomically. Since the leap appears to have no anatomical basis, Dawkins suggests it was as if the H. sapiens brain had acquired advanced software. Intelligent design proponents might well claim that Dawkins is proposing a "God of the gaps" explanation. It will be interesting to see how science closes this gap, as it has closed so many in the past.
Albert J. LeoOntario, California
The letters in response to "Darwin's Rottweiler" were every bit as interesting as the article itself. I found it quite entertaining that one writer labeled believers in creationism or the divine as "pathetic" or "idiots," yet in doing so he seems to have abandoned his own belief! As any competent practitioner of science can tell us, many phenomena exist or are understood that were at one time unobserved or unexplained. Any proclamation that "God does not exist" is definitely not a scientific statement, and antitheists cannot prove that creationism is wrong any more than they can prove that art is art.
Robert Smith says that people who criticize creationism are going about it the wrong way because creationists "disengage" when their concepts are insulted or ridiculed or attributed to some sort of mental deficiency. He further asserts that Dawkins represents a "politicized, agenda-driven, intolerant variety of science." I agree that the rank and file of the movement don't need to be insulted by anybody, but I assert that the people behind "scientific" creationism represent a politicized, agenda-driven variety of pseudoscience.
Anthony W. DunlapChillicothe, Ohio
Please cancel my subscription to Discover. I can find sufficient agnostic, atheist, Marxist Bush-bashing just by turning on the television. I don't need my dose of science riddled with the drama and hate of liberals. After reading your article about Dawkins and his ardent disdain of religion and faith and the subsequent response of readers, I have decided to go to the library and burn all books of scientific theory, which of course, includes evolution. Us dumb red-staters must only have science that has been proven, and there is no room for alternative thought.
Eldon W. RollinsCoquille, Oregon
NUTRITION FACTSFrontiers of Science: Nutrition [October] by Jennifer Kahn featured an interview with Walter Willett, a professor of epidemiology and nutrition at the Harvard School of Public Health. Willett's response to the question "Why aren't people getting enough vitamin D these days?" surprised me: "Vitamin D is unusual in that we don't get it from our food: We synthesize it by being out in the sun." While it is true that our major supplier of vitamin D is the sun (90 percent), Willett must be aware that several foods (not fortified) are also high sources of this vitamin. Several fish and fish extracts, such as salmon, mackerel, and especially cod liver oil, top this list. One tablespoon of cod liver oil provides approximately 340 percent of the recommended daily allowance of vitamin D.
David FoucartBremen, Ohio
Patrick D. BoltLeesburg, Virginia
The RDA for vitamin D is low—just the bare baseline for preventing rickets but not enough to prevent other, subtler effects, like increased cancer risk. So the fact that cod liver oil provides three times the RDA may not matter so much. Not many people get lots of cod liver oil in their diet these days or eat enough of the right kind of fish to get a substantial amount of vitamin D. Most fish have less than 100 international units per serving, and our bodies produce 10,000 to 20,000 I.U. per day if exposed to the sun. —Jennifer Kahn
ERRATA
We would like to thank design engineer Paolo Salvagione for his invaluable assistance in developing and explaining the graphics used in "Time Machine" (November). We referred to "Sir Richard Dawkins" in our headline for "Darwin's Rottweiller" (September). Professor Dawkins has not been knighted...yet.
