Bird Thou Never Wert
Many thanks to David Lubman for demystifying a phenomenon I have long puzzled over ["The Chirping Pyramid," Breakthroughs, February]. When, as a child, I clapped outside the storefront of a nationally recognized discount store, I would hear a "chirping" echo. The store's concrete wall was finished with shallow, closely spaced corrugations that must have acoustically resembled a Mayan staircase.
I now understand the mechanism of the phenomenon, but several questions remain. What bird sound were these builders trying to replicate? What sort of rituals would be appropriate for a parking lot such as this one? How did this technology propagate from the Mayan pyramid to contemporary New England architecture? People wishing to experience the "ancient mystery" can put their hands together under the big red "K" in Westfield, Massachusetts.
Methinks the author doth suggest too much about the conquistadors' reaction to human sacrifice as performed by the Aztecs ["Temples of Doom," March]. As verified by history, the Spanish had their own versions.
If I had my druthers, I would choose having my heart torn out over swallowing molten lead, being broken on the rack, or being put in the iron maiden--all favorite tortures during the Spanish Inquisition.
Jack E. Ingham
The findings at the Moche temples could have been put in a broader context and described with less goggle-eyed pseudohorror. How would someone describe European-style capital punishment? For instance: Hanging, drawing and quartering, crucifixion, impaling, or centuries of burning people alive at the stake? The great Renaissance princes put the heads of decapitated enemies on the gates of their cities and left hanged bodies for the birds. Were these ritual sacrifices? And what of the mass killings of the twentieth century in Europe, Chile, Argentina, Cambodia, Nicaragua, Guatemala, El Salvador? We label our human sacrifice as capital punishment or punishment for religious heresy; only "primitives" engaged in "ritual."
Santa Fe, N. Mex.
Heather Pringle places great emphasis on the religious or ritualistic aspect of human sacrifice with little attention to the cannibalistic element. That choice limits our understanding of this phenomenon. In A New World, by Arthur Quinn, there are numerous references to eyewitness accounts of torture and cannibalism among the northeastern tribes. Jesuits, trappers, and soldiers reported on both.
Torture has persisted throughout history. Cannibalism, however, has been much more restricted and has declined. Why were the Amerindians one of the last groups to abandon the practice? Why was it practiced in the hemisphere as late as the eighteenth century? What is unique in Amerindian culture or religion that makes it acceptable? These are more compelling questions than how the process was carried out.
Robert J. Chitester
In Search of the Tooth
John Verano's photograph of the lateral view of a bashed-in skull shows the victim with only one right bicuspid, or premolar. (There are normally two bicuspids in the arch.)
Was this a common trait among the Moche, and if so, how do you explain this variation? It appears their dentition was in excellent condition; no decay and little periodontal disease. Of course, their mean age at death was just 23.
Richard B. Fink, D.D.S.
John Verano replies: The skull is missing only one premolar, on the right side. Its upper lateral incisors and third molars are smaller than normal, so I think it is a case of congenital absence of one premolar with similar, but less serious, effects on the other teeth. I have seen very few cases of congenitally absent premolars in my north-coast samples, but absence of one or more third molars is relatively common.
Geckos on the Ceiling
Having assumed that geckos had suction pads on their feet ["Paradise and Oil," March], I made--and lost--a bet that they were amphibians. I couldn't imagine a reptile having the strange and delicate skin required for suction pads. Geckos are, in fact, reptiles. Their feet have pads with microscopic backward-projecting hooks that cling even to the smallest surface irregularity.
The Zen of Traffic
I believe that the researchers' hypothesis ["The Physics of . . . Traffic," March] was to some extent proved on Chicago's Outer Drive in the late forties and early fifties. On the occasions that I had to use it during evening rush hours, traffic, once organized, usually flowed three lanes wide in a near-perfect "gridlock" at 45 miles per hour for most of a six-mile stretch. There were entrance and exit ramps about every half mile, but once out of the Loop, almost no traffic entered, and leaving was usually unencumbered. Trucks were prohibited, so spacing became very regular, and I'm sure the density was much greater than the 35 cars per mile per lane proposed in your article. Many locals refused to use "the Drive," and the rare "tourist" showed up as a defect in the structure. Of course, if a major defect occurred, the pattern reverted to the usual chaos. But when it worked, it was beautiful!
Spiraling Down the Drain
You have perpetuated the common misconception that the Coriolis effect causes bathtubs to drain in a spiral ["In Search of the Elusive Megaplume," March]. A related misconception is that draining water spirals in one direction in the Northern Hemisphere and in the reverse in the Southern Hemisphere (again, due to Coriolis). In fact, the Coriolis force affects only very large-scale systems; bathtub drains (and even natural whirlpools) are much too small to be significantly affected by Coriolis.
American Meteorological Society
A Better Way to Slice a Starfish
Regarding your reply to Wendell Coleman [Letters, March]: starfish are bilateral animals. Their often-cited radial symmetry is really pseudoradial symmetry. Starfish possess a structure called the madreporite, or sieve plate--the opening through which their hydraulic locomotion system takes in water. This is a single, nonpaired structure. Thus there is only one true plane by which a starfish can be bisected into two mirror images, one that passes through the middle of the madreporite.
John C. Jahoda, Ph.D.
Professor of Zoology
Bridgewater State College