Logansport Pharos-Tribune from Logansport, Indiana on March 23, 1988 · Page 17
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Logansport Pharos-Tribune from Logansport, Indiana · Page 17

Logansport, Indiana
Issue Date:
Wednesday, March 23, 1988
Page 17
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Pharos-Tribune, Logansport, Indiana, Wednesday, March 23, 1988 Page 17 Electric current Superconductivi Direction of current An electric charge flows through ordinary conductive material in the form of subatomic electrons. The negatively-charged electrons encounter resistance in the conductive material and are scattered by collisions with atoms, impurities and other electrons. The collisions waste energy and slow the current. Direction of current At very low* temperatures, an electron pulls the positively-charged atoms of the superconductive material inward, forming an area of excessive positive charge. This attracts another negatively-charged electron and binds the two electrons together. The momentum of the paired electrons eliminates all resistance to the flow of current. 'Physics of higher-temperature superconductivity is uncertain Chicago Tribune Graphic; Sources: National Science Foundation and Encyclopaedia Brltannica Comet Hunter Snags Fourth In Four Years TUCSON, Ariz. (AP) - An amateur astronomer has discovered his fourth comet in four years after going 19 years without spotting one. "I'm getting much more persistent about it, and I'm becoming much more single- minded about it," said David Levy, a research assistant at the University of Arizona's Lunar and Planetary Laboratory, whose latest discovery came last weekend. "I take advantage of almost every opportunity to search for comets." The find was confirmed Tuesday by Brian Marsden of the International Astronomical Union, who said Levy now has more new comet sightings than any other living U.S. amateur. The comet was designated Comet 1988e — signifying it is the fifth comet discovered this year. Levy said he spends between one and four hours each clear night scanning the skies with one of his dozens of telescopes. He has been searching for comets for 23 years. After 19 years without a find, he co- discovered Comet Levy-Rudenko in 1984. In January 1987, he spotted the first comet of that year. Levy built a 6-by-8-foot wooden platform atop his home last October to get a better view of the horizon. Three days after its completion, he spotted his third comet. He said he found his fourth cornet about an hour before dawn on Saturday, just above the horizon. He was using a 16-inch telescope. Threads' thought to be electrons trapped in a vast electromagnetic filed generated by black hole, forming a 100-light-year-long aurora borealis. Plane of the ecliptice around which galaxy rotates 30,000 light years from Earth the center of the Milky Way may be a black hole. Milky Way Survey To Yield New View LOS ANGELES (AP) — The most detailed survey of the Milky Way will start Thursday at the world's most sensitive radio telescope, an array of 27 dish- shaped antennas spread across New Mexico's desert. "Without a doubt this will give us the most comprehensive picture of our galaxy yet obtained in any kind of wavelength," including visible light and radio and infrared radiation, said Robert H. Becker, associate professor of astronomy at the University of California, Davis. The $1 million, two-year survey will be conducted by Becker and astronomer David Helfand of Columbia University. They will use the Very Large Array radio telescope, a set of 27 antenna dishes, each about 80 feet in diameter, that move on 20 miles of tracks west of Socorro, N.M. The telescope, which started operations in the late 1970s, can detect fainter radio signals than any other radio telescope, Becker said Tuesday during a telephone interview. More complete surveys of the heavens beyond our galaxy have been conducted using powerful optical and infrared telescopes aimed to look above or below the Milky Way's flattened disk. But such telescopes can't survey our own galaxy very well because visible light is blocked by tremendous amounts of dust between the Milky Way's stars and because the galaxy is so full of infrared light sources that it's hard to distinguish various objects, Becker said. The survey will construct maps of the 70 percent of the Milky Way visible from the Northern Hemisphere by detecting objects that emit radio waves, which penetrate the dust. Such objects include supernovas, or dying, exploding stars; vast dust-and-gas clouds where new stars are born; and very dense supernova remnants called neutron stars, pulsars and black holes. "What this kind of survey can do is give you the overall picture." Becker said. "Until you catalog the contents of your own galaxy, you're never going to have a clear picture of what the galaxy is." The disk-shaped Milky Way contains an estimated 100 billion stars clumped in spiraling arms that stretch across 100,000 -light years, or about 588,000 trillion miles, of space. Earth is located roughly 22,000 light years, or 130,000 trillion miles, from the galaxy's center. Becker said the survey undoubtedly will produce unexpected discoveries, but also could help astronomers determine the frequency and location of supernova explosions invisible to optical telescopes. Superconductivity Research Temperature to reach superconductivity being lowered NEW ORLEANS (AP) — Progress in superconductivity continues at a frantic pace as new superconductors are discovered, better methods of making them are perfected and scientists begin to understand how they work, physicists say. Their reports were delivered Tuesday night at a meeting of the American Physical Society and followed by one year the so-called "Woodstock of physics" at which the first breakthroughs in superconductivity were reported. A year ago, physicists had broken the liquid nitrogen barrier, when Paul Ching-Wu Chu of the University of Houston reported the discovery of a superconductor that carried electricity with zero re- sistance at minus 283 degrees Fahrenheit — above the temperature of liquid nitrogen. That opened the door to wider use of superconductors, because liquid nitrogen coolant is cheaper and more widely available than the liquid helium used for lower temperatures. Researchers have speculated that superconductors might one day lead to magnetically levitated, 300 mph trains and to much cheaper means of distributing and storing eletricity. As research has progressed, however, many now do not expect those applicati9ns for decades. Allen Hermann of the University of Arkansas was one of the hundreds of physicists who jumped on the supercon- ductivity bandwagon last March, but unlike many of the others, he capped the year with perhaps the most exciting recent finding. Hermann and his colleague Zhengzhi Sheng discovered a superconductor that has since set a record for high temperatures. In February, Hermann and Sheng announced the discovery of I he compound, containing thallium, barium, calcium, copper and oxygen. It became supercon- ducting at approximately 274 degrees below zero. Within days, Edward Erigier and colleagues at IBM's Almaden Research Center in San Jose, Calif., pushed the figure to minus 234 degrees by varying the recipe. Just For The ^W ,/JJiW :M Of It SALE layiMh' Days Only Thurs, Fri. ft Sal. Off currently marked price e o : <£* ?57 Entire Stock (Including Bikes fc.Wheel Goods) Selection of toys will vary from store to store. WOO, K- i=jj -1 -y (iJIffTtHBtU) ,99 Reg. 15.99 Flower Cart Warm Weather Favorite Ladies' Sandal Tied pastel bands, adjustable stiap. Si.'c to 10 Special Purchase >wm< FEMtiZfi 97 f?eg. 3.99 Fertilizer 12-12-12 all purpose 20 pounds r W 99 7 Reg. 14.95 Disney Movies Popular Walt Disrey video movies. "New Shipment" Large 10" House Floor Plants 10°/o Discount Given To Senior Citizens (Age 60 & Over) Every Tuesday f 4 97 I Reg. 15.99 Semi Desk Top Sharp Calculator Solar Poweied N.J. EL335AB n^s e«i 'Wft ^» Whoppers Real Malted Milk Candy Balls 15 oz. AH Pepsi Products ) 2 Pack Cans 30% off 4 Servin' Savers 3 For Reg 89' oo. Scotch Magic Tape '/j"x 540" Bonus Pack. DOUBLE MANUFACTURER'S COUPONS Everyday Bring in your manufacturer's coupons of 50' value or less and we'll give you a maximum of M off. Any coupon over 50 C will be redeemed for a maximum of s l or face value. See stores for complete details. VISA Prices Good Thurs., Mar. 24 Thru Sat., Mar. 26

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