Word: circadian
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Dates: during 1960-1969
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...Circadian Rhythms. NASA has suggested that such nighttime illumination would be useful in search-and-rescue work, in spacecraft-recovery operations and in lengthening short winter days at high latitudes. But its spokesmen have carefully avoided discussing another obvious application: military use in Viet Nam. A single mirror satellite in synchronous orbit over Southeast Asia could cast light on an area stretching from Saigon all the way to Pointe de Camau, at the southern tip of Viet Nam, thus depriving guerrillas of the protection of darkness...
Despite these practical applications, many scientists share Physicist Everhart's concern about the space mirrors. Biologists fear that decreasing the hours of darkness could disturb the delicate circadian rhythms that control many life processes. Other scientists envision a mirror swinging out of control, reflecting sunlight indiscriminately over the night face of the earth. Even more alarming to Everhart is the potential proliferation of the mirrors. "Farmers would demand them to plow their fields at night," he says, "and resort owners would want them to light their lakes and pools." Singlehanded, Everhart has mounted an intensive campaign to rally...
Adrenal Tides. Such time-zone crossings foul up man's daily physiological cycles, the "circadian rhythms"* that are still one of nature's deepest mysteries. No matter where he lives on earth, man becomes adjusted to daily cycles of activity and sleep that correspond roughly to the cycles of light and dark. But it is by no means a simple matter of day and night. Man seems to have both wakefulness and sleepiness centers, and the two interact-one switching off the other. Man also has temperature cycles; if he stays up late enough, he will feel chilly...
...days of a long-awaited European or Hong Kong holiday, but without scientific testing there was no way to know whether the complaints reflected changes in longitude or overindulgence in food and liquor on the plane. What Hauty wanted now was reliable data that might help him predict circadian effects on pilots' performance during long jet flights, on astronauts whose "days" get shortened to less than 100 minutes, and finally, on weary passengers...