Word: ultraviolet
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...subcommittee, "because observations indicate the water vapor content of the stratosphere has already increased about 50% over the last five years." A water-vapor blanket, Train contends, could lead to greater ground-level heat and hamper the formation of ozone that shields the earth from the sun's ultraviolet rays...
Exactly what caused that chemical concatenation has long been the subject of lively scientific debate. Was the crucial reaction powered by intense ultraviolet radiation from the sun? By bolts of lightning in the primeval skies? Or by the searing heat of volcanic eruptions on the surface of the young planet? Researchers have found that amino acids can be produced in laboratory simulations of each of those conditions. Now a team of investigators at Cornell University has proposed that another natural phenomenon might have played a role. The catalyst of genesis, they say, could have been the shock waves of thunderclaps...
...process was remarkably efficient. Carl Sagan, director of Cornell's Planetary Studies Laboratory, calculates that as much as 36% of the ammonia was converted into amino acids-a far better yield than that obtained in tests using ultraviolet radiation. Reason: the temperature rises resulting from the shock waves were too brief to break up any of the newly formed molecules. Indeed, the shock-tube process worked so well that Sagan has suggested a highly practical application: a cheap method of making amino acids for protein food supplements to fight malnutrition...
Guillet's team got around such problems by finding a way to chemically bond groups of "sensitized" molecules directly into the plastic's carbon chain. When these "S" groups absorb ultraviolet light from direct sunlight, he says, their carbon "backbones" soon begin to be decomposed by microorganisms. But indoors-even in front of glass windows-they will not be affected. Guillet claims that the speed of the breakdown can be controlled by varying the number of "S" groups bonded into the plastic molecules. He also thinks that the process would raise the price of plastics by only...
...South Atlantic in less than 40 hours. But that strategy too carried unnecessary risks. It would so deplete the LM's fuel supply that later course corrections might not be possible. Also, loss of the service module would expose the command module's heat shield to possibly damaging ultraviolet radiation and temperature extremes, leaving the astronauts with insufficient protection for reentry...