For your information. --O. Johns W6ODJ
Begin forwarded message: > ---------------------------------------------------------------------- > This article was sent to you by someone who found it on SFGate. > The original article can be found on SFGate.com here: > http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2011/05/23/BABK1JIVEQ.DTL > --------------------------------------------------------------------- > Monday, May 23, 2011 (SF Chronicle) > Robert Helliwell, radio science pioneer, dies > "mailto:[email protected]";>David Perlman, Chronicle Science Editor > > > When Robert A. Helliwell, a Stanford electrical engineer, heard a > mysterious series of high-pitched, drawn-out whistles coming from his > laboratory's radio receiver more than 60 years ago, his curiosity led him > to a pathbreaking series of experiments exploring Earth's magnetic field > and the belt of energetic particles beyond it. > With great delight over the years, he regularly welcomed visitors to his > lab to listen to what he called his "whistlers," the eerie electrical > warbling generated by lightning flashes in Canada's Arctic and that had > sped for thousands of miles through the ionosphere to Stanford. > Professor Helliwell, a distinguished radio science researcher, died May 3 > in Palo Alto of complications from dementia. He was 90. > During his research, Professor Helliwell once enlisted a powerful Navy > transmitter to send signals from Annapolis, Md., to a Chilean listening > post in a lighthouse at Cape Horn. It led him to discover that Earth's > ionosphere was not 200 miles thick, as scientists had believed, but > extended at least as high as 20,000 miles. > Continuing that research, Professor Helliwell sent radio transmitters into > space aboard NASA satellites to explore the radio properties of the Van > Allen Belt, where highly energetic electrons and protons trigger the > aurora borealis, the brilliant northern lights. > In Antarctica, where the atmosphere was unsullied by radiation from urban > power lines and radio noise, Professor Helliwell and his students > installed a very low frequency transmitter at Siple Station, a research > base 900 miles from the South Pole, and deployed an antenna array 13 miles > long. > It sent radio signals to Canada and, because the Antarctic ice sheet is 1 > 1/2 miles thick, the antenna in effect was 1 1/2 miles high above Earth. > Little of the very low frequency radio energy, therefore, was absorbed by > the ground and the signal from Siple was able to follow Earth's magnetic > field lines far out into space before returning to Earth in Roberval, > Canada. > "It was like a lab experiment in space," recalled Donald Carpenter, an > emeritus professor of electrical engineering at Stanford and one of > Professor Helliwell's former students. > "He was always a very curious guy," Carpenter said, "and if you came to > him with a question, he'd answer, but you'd come away with still more > questions. He was a gold mine of insights into the behavior of the > ionosphere and the magnetosphere, and the Van Allen radiation belts." > Professor Helliwell's radio frequency experiments at Siple Station were > "his crowning achievements," Carpenter said. > The scientific world honored him for his work there, and in 1966 the > government's Board of Geographic Names named a stretch of mountains along > the coast of Antarctica's Victoria Land as the "Helliwell Hills." > Professor Helliwell was born in Red Wing, Minn., and joined the Stanford > faculty in 1946 after earning all his university degrees there. > His high school sweetheart, Jean Perham, also graduated from Stanford. And > when Professor Helliwell joined the fencing team as an undergraduate, she > did too - going on to become the university's first female fencing coach. > Mrs. Helliwell died in 2001. > Professor Helliwell is survived by his sons, Bradley of Sedona, Ariz., > David of Arcata (Humboldt County), and Richard of Colorado Springs; a > daughter, Donna of Sunnyvale; four grandchildren; and one > great-great-grandchild. > A memorial service will be held at the Stanford Memorial Church on June 7 > at 3 p.m. E-mail David Perlman at [email protected]. > ---------------------------------------------------------------------- > Copyright 2011 SF Chronicle > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
