Imponderables

This Imponderable assumes two facts that aren’t always true. First, not all ruins are the remains of cities. Many other ancient sites—such as forts, camping sites, cave dwellings, cemeteries, and quarries—are also frequently buried. Second, not all ancient cities are buried; once in a while, archaeologists are given a break and find relics close to or at the surface of the ground. Still, the questions are fascinating, and we went to two experts for the answers: George Rapp, Jr., dean and professor of geology and archaeology of the University of Minnesota, Duluth, and coeditor of Archaeological Geology; and Boston University’s Al B. Wesolowsky, managing editor of the Journal of Field Archaeology. Both stressed that most buried ruins were caused by a combination of factors. Here are some of the most common

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Wind-borne dust (known to archaeologists as “Aeolian dust”) accumulates and eventually buries artifacts. Aeolian dust can vary from wind-blown volcanic dust to ordinary dirt and house dust

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Water-borne sediment accumulates and eventually buries artifacts. Rain carrying sediment from a high point to a lower spot is often the culprit, but sand or clay formed by flowing waters, such as riverine deposits gathered during floods, can literally bury a riverside community. Often, water collects and carries what are technically Aeolian deposits to a lower part of a site

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Catastrophic natural events can cause burials in one fell swoop, though this is exceedingly rare, and as Dr. Rapp adds, “In these circumstances the site must be in a topographic situation where erosion is absent or at least considerably slower than deposition.” Even when a city is buried after one catastrophe, the burial can be caused by more than one factor. Dr. Wesolowsky notes that although both Pompeii and Herculaneum were buried by the eruption of Mt. Vesuvius in A.D. 79, one was buried by mudflow and the other by ash flow

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Manmade structures can collapse, contributing to the burial. Sometimes this destruction is accidental (such as floods, earthquakes, fires), and sometimes intentional (bombings, demolitions). Humans seem incapable of leaving behind no trace of their activities. Says Rapp: “Even cities as young as New York City have accumulated a considerable depth of such debris. Early New York is now buried many feet below the current surface

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Occasionally, ancient civilizations did their own burying. Wesolowsky’s example: When Constantine wanted to build Old St. Peter’s on the side of the Vatican Hill in the early fourth century, his engineers had to cut off part of the slope and dump it into a Roman cemetery (thereby preserving the lower part of the cemetery, including what has been identified as the tomb of Peter himself) to provide a platform for the basilica. When Old St. Peter’s was demolished in the sixteenth century to make way for the current church, parts of the old church were used as fill in low areas in the locale. Rapp’s example: This phenomenon is best seen in the tels of the Near East. Often they are tens of feet high. Each “civilization” is built over the debris of the preceding one. The houses were mostly of mud brick, which had a lifetime of perhaps sixty years. When they collapsed the earth was just spread around. In two thousand or three thousand years these great habitation mounds (tels) grew to great heights and now rise above the surrounding plains. Each layer encloses archaeological remains of the period of occupation. While we self-consciously bury time capsules to give future generations an inkling of what our generation is like, the gesture is unnecessary. With an assist from Mother Nature, we are unwittingly burying revealing artifacts—everything from candy wrappers to beer cans—every day

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Rain is water. Water is light in color. Rain clouds are full of water. Therefore, rain clouds should be light. Impeccable logic, but wrong. Obviously, there are always water particles in clouds. But when the particles of water are small, they reflect light and are perceived as white. When water particles
become large enough to form raindrops, however, they absorb light and appear dark to us below

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Virtually all living organisms can digest sugar easily. So why
isn’tsugar prone to the same infestation as flour or other kitchen staples? Because
sugar has an extremely low moisture content—usually about 0.02 percent—it
dehydrates microorganisms that might cause mold. As John A. Kolberg,
vice-president of operations at the Spreckels Division of Amstar Corporation,
explains it, “Water molecules diffuse or migrate out of the microorganism at a
faster rate than they diffuse into it. Thus, eventually the microorganism dies due
to a lack of moisture within it.” Sugar’s low moisture level also impedes
chemical changes that could cause spoilage. All bets are off, however, if sugar
is dissolved in water. The more dilute the sugar solution, the more likely
yeasts and molds will thrive in it. Even exposure to high humidity for a few
days will allow sugar to absorb enough moisture to promote spoilage and mold. Storing
sugar in an airtight container will retard the absorption of moisture even in
humid conditions. If stored in an atmosphere unaffected by swings in
temperature and humidity, sugar retains its 0.02 percent moisture level and has
an unlimited shelf life

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Daniel Boone, a University of Arizona professor and expert on vocal mechanisms, provides the answer: “Fundamental frequency or voice pitch level is directly related to the length and thickness of the individual’s vocal folds [or vocal cords].” The average man’s vocal-fold length is approximately eighteen millimeters; the average woman’s is ten millimeters. The tall person of either gender is likely to have longer vocal cords than a shorter person of the same sex .

An important question, one that philosophers throughout the ages have
pondered. Luckily, ornithologists know the answer. That black dot is fecal
matter. The white stuff is urine. The urine and fecal matter of birds collect
together and are voided simultaneously out of the same orifice. Feces tend to
sit directly in the middle of droppings because the urine, slightly sticky in
consistency, clings to them

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 We talked to two specialists in aviation medicine who assured us that there is no reason why atmospheric changes in airplanes would cause feet to swell. Both assured us that the reason your feet swell up on a plane is the same reason they swell up on the ground—inactivity. Your heart is not the only organ in the body that acts as a pump; so do the muscles of the legs. Walking or flexing a leg muscle assists the pumping effect. On a plane, you are not only confined in movement but sitting with the legs perpendicular to the floor. If you sit for prolonged periods without muscular activity, blood and other fluids collect in the foot with the assistance of gravity. It doesn’t really matter whether you leave your shoes on or off during periods of inactivity. If left on, they will provide external support, but they will inhibit circulation, feel tight—and will not prevent feet from swelling, in any case. If you take your shoes off, you will feel more comfortable, but you’ll have a tough time putting your shoes back on, and most of us don’t take our shoehorns along on planes. The pooling of fluids in the feet can happen just as easily in a bus, a train, or an office. Most people’s feet swell during the day, which is why the American Podiatric Association recommends buying shoes during the middle of the afternoon. Many people require a shoe a half size to a full size larger in the afternoon than when they wake up. If your feet swelling becomes a problem, consider airplane aerobics. A few laps around a wide-body plane will do wonders for your feet and will build up your appetite for that wholesome and delicious airplane meal that awaits you

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The Celsius system, for example, is less precise than the Fahrenheit in distinguishing slight variations in moderate temperatures. Thus while 180 increments on the Fahrenheit Scale are necessary to get from the freezing (the freezing point is 32° )  to the boiling point(the boiling point is 212°)  , the freezing point (0°) on the Celsius scale and the boiling point (100° C) are closer, only 100 increments apart

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Whips can attain a speed of more than seven hundred miles per hour when snapped, breaking the sound barrier. What you are hearing is a mini sonic boom

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Florence Nightingale always wore a white uniform. White, of
course, is a symbol of purity, and in the case of a nurse, an appropriate and practical one—white quickly shows any dirtiness. Surgeons also wore white until 1914, when a surgeon decided that red blood against a white uniform was rather repulsive and needlessly graphic. The spinach green color he chose to replace it helped neutralize the bright red. At the end of World War II, the lighting was changed in operating rooms, and most surgeons switched to a color called “misty green” .  Since about 1960, most surgeons have used a color called “seal blue,” which contains a lot of gray. Why this latest switch? According to Bernard Lepper, of the Career Apparel Institute ofNew York City, seal blue shows up better on the TV monitors used to demonstrate surgical techniques to medical students

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In baseball, horse racing, and most forms of skating, we are accustomed to seeing a counterclockwise movement. Is there any particular reason why clocks run “clockwise”? Henry Fried, one of the foremost horologists in theUnited States, gives a simple explanation for this Imponderable. Before the advent of clocks, we used sundials. In the northern hemisphere, the shadows rotated in the direction we now call “clockwise.” The clock hands were built to mimic the natural movements of the sun. If clocks had been invented in the southern hemisphere, Fried speculates, “clockwise” would be the opposite direction

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