Pyramids are not made of polymers, say experts A theory that the building blocks of the pyramids are mineral polymers cast on the spot ran into polite but stony opposition from archaeological scientists last week. Researchers attending the 1984 Symposium on Archaeometry, held in Washington, D.C., at the Smithsonian Institution, found evidence for the controversial idea—presented by polymer chemist Joseph Davidovits—less than rock solid. For a number of years, Davidovits has been promoting his theory that ancient monuments such as the pyramids and the Easter Island statues were constructed from man-made stone—crushed rock agglomerated with an organic binder. Instead of cutting and hauling huge stones, Davidovits asserts, ancient peoples built molds to form the stones using the low-temperature polymerization process he has rediscovered
at his geopolymer institute at Barry University in Miami Shores, Fla. X-ray diffraction analysis of casing stone from the pyramids of Cheops and Seneferu show the materials could not have come from the Egyptian quarries they are traditionally associated with, Davidovits told the researchers. Samples from the quarries showed the rock there to be pure limestone, whereas the pyramid stones contain a small percentage of other materials—most notably hydroxyapatite—indicative of a geopolymeric binder, Davidovits says. Davidovits' audience seemed eager to chip at his theory. The British Museum finds nothing that can't be explained as natural limestone— including no hydroxyapatite—in its samples from Cheops, Michael S. Tite, an archaeological scientist with the museum's research lab, quickly
USDA readies live-in calorie counter Why some people get fat but others do not on similar amounts of food and exercise is one of the questions to be examined using a new human calorimeter under construction by the U.S. Department of Agriculture in Beltsville, Md. Here being readied by USDA researchers, the calorimeter will house a volunteer for two days to two weeks, depending on the particular study. With 16,000 temperature sensors embedded in the interior walls, the chamber is designed to measure temperature changes in the air of 0.001 °C, easily monitoring the 1600 to 2400 calories per day expended by an average size adult. The operation is under computer control, as is a mass spectrometer that will constantly compare percentages of oxygen, nitrogen, and carbon dioxide in air entering and leaving. According to Clarence E. Bodwell, chief of the USDA protein nutrition lab, the unit is the first in the U.S. to combine direct and indirect calorimetry to measure energy produced by metabolizing food in the human body.
pointed out. Another speaker suggested Davidovits check quarry samples from the west, rather than the east side of the Nile. Still other researchers wondered if Davidovits had checked the microstructure of a cross section of the pyramid stone—an experiment that would clearly differentiate natural stone from man-made aggregate. Davidovits skirted the question—a response that seemed only to solidify his colleagues' resistance to his ideas. •
Agent orange pact hits Monsanto hardest More light was shed last week on how the seven defendants in the agent orange suit are apportioning their payments to the $180 million settlement fund agreed upon jrst before the scheduled beginning of the trial May 7 (C&EN, May 14, page 6). To all appearances, Dow Chemical, which had the largest share of sales of agent orange to the government, will not pay the largest share of the settlement. Instead, Monsanto, which Dow had charged with responsibility for most of the dioxin contamination in the Vietnam War herbicide, will make the biggest individual payment. A spokesman for Hercules, another of the defendants, confirmed as "pretty authentic" reports that the apportionment formula worked out among the seven companies made Monsanto's share about 45%, Dow's about 20%, Diamond Shamrock's 12%, Hercules' 10%, TH Agriculture & Nutrition's 6%, Uniroyal's 5%, and the now-defunct Thompson Chemicals' 2%. The formula itself has not been made public officially; the defendants agreed at the time of the settlement to keep it secret. But Paul F. Oreffice, chief executive of Dow, revealed at the company's annual meeting May 11 that Dow is "not paying the largest share among the seven companies involved." The apportionment seems to be a compromise between Dow's assertion last year that any formula for payments should be based strictly on the amount of dioxin contaminaMay 21, 1984 C&EN
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