A particularly brilliant and demanding manager for whom your editor used to work had a “SO WHAT?” stamp with which he would critique our technical papers and proposals. His point in defacing our papers was not to be snide, but to force us to defend why we included certain facts – interesting though they may be in themselves. Two different and equally brilliant discoveries by University of Cambridge and University of California, Riverside researchers bring the “so what?” stamp to mind. Even with their breakthroughs, approaching 100-percent efficient solar cells in the first instance, solar cells may not yet be a perfect fit for aircraft propulsion. Each square foot of the earth’s surface receives about 15 Watts of solar energy during a bright day. 100 square feet of solar cells (about what we could expect for an average-size wing on an average light plane) would see 1.5 kilowatts hitting that surface – not enough to sustain flight on anything but …
More Heat Than Light – But Energetic, Nevertheless
Mars Curiosity Rover is bigger than one would expect, over six feet tall and weighing 1,982 pounds. It travels up to 660 feet per day on its multiple wheels, looking for rocks to analyze with its ChemCam. Powered by the heat from its plutonium reactor, Curiosity will rove Mars for two years if all goes well. The heat is converted to electricity (which then drives the wheel motors on the rover) by a lead telluride thermoelectric material, a semiconductor which, capable as it is, has been eclipsed in efficiency by a new form of the material developed by Northwestern University researchers. Mercouri G. Kanatzidis, the Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences, explains that his heat exchange material is twice as efficient as that used on Curiosity, a breakthrough with potential uses to boost car mileage, improve industrial processes, and maybe even make hybrid aircraft more efficient. Currently used materials have …