Новости науки и техники в "Scientific American"
1 июля 2003 г. |
HARVESTING HYDROGEN FUEL FROM PLANTS GETS CHEAPERA major roadblock to widespread use of hydrogen-powered electric vehicles, which emit water vapor as a byproduct and could cut greenhouse gas emissions substantially, is the cost and trouble associated with producing a suitable supply of hydrogen. Last year scientists reported having developed a technique to harness the fuel from biomass, but the catalyst required for the reaction was too expensive to be commercially viable. The same researchers have now discovered a different catalyst that works just as well - at a fraction of the cost.GIGANTIC JETS CONNECT THUNDERCLOUDS TO THE IONOSPHEREThe most common kind of lightning shoots down from clouds toward the ground. More elusive forms, dubbed sprites and blue jets, flit above the clouds. Now scientists have discovered another type of lightning - gigantic jets - that links the tops of clouds to the overlying charged atmosphere, known as the ionosphere.TECHNIQUE MAY SIMPLIFY NANOTECH MANUFACTURINGIt can be hard to wrap your brain around the concept of nanotechnology considering the scales involved are one millionth the size of a pinhead or one thousandth the size of a typical bacterium. But for scientists manufacturing these tiny devices, the hard part is actually sorting through nanowires and connecting them to the microelectronics. A novel approach to nanotech manufacturing may help avoid this cumbersome step. Researchers have successfully grown silicon nanowires directly on a sensor surface at room temperature.BRAIN IMAGES HIGHLIGHT HOW PEOPLE FEEL PAINWhen it comes to pain, some people are tougher than others. New findings suggest that these differences are all in the head. Researchers have shown for the first time that variation in how people perceive pain results from differences in brain activity.NEW THERMOMETER READS TEMPERATURE FROM NOISEScientists have designed a new kind of thermometer that uses noise to measure temperature. The device gives highly accurate readings between room temperature and one kelvin, and does not require outside calibration.ASK THE EXPERTS: WHY DO OZONE-DEPLETING CHEMICALS NOT DIFFUSE EVENLY (AND CAUSE A GENERAL THINNING OF THE OZONE LAYER) BUT INSTEAD CAUSE HOLES AT THE POLES?David Fahey of the National Oceanic and Atmospheric Administration's (NOAA) Aeronomy Laboratory in Boulder, Colo., explains.