Sep 21, 2009 | 25
Martin Campbell-Kelly’s September article on the origins of computing traces the history of machine computation from Charles Babbage, the 18th century British mathematician, through the 20th century. Yet according to many of our readers, we made a critical omission.
John Hauptman, a professor of physics at Iowa State University, writes:
The first person to build and operate an electronic digital computer was a physics professor, as correctly noted in your excellent article “Dr. Atanasoff’s Computer,” Scientific American, August 1988 [not online]. Atanasoff’s first computer was a 12-bit 2-word machine running at 60Hz wall-plug frequency and could add and subtract binary numbers stored in a regenerative memory using a logic unit built with seven triode tubes. This was 1937. There was no war, no Pearl Harbor, just a theoretical physicist trying to solve problems in quantum mechanics with his students at Iowa State College in Ames, Iowa.
Dec 4, 2008 | 24
As world leaders meet in Poznan, Poland this week and next to discuss efforts to reduce greenhouse gas emissions causing global warming, it's worth remembering that scientists have known climate change could be a problem for a long time.
Irish scientist John Tyndall first speculated that human-induced global warming might be possible back in 1861 and Nobel Prize-winning chemist Svante Arrhennius had confirmed climate change (with laborious pencil and paper calculations rather than the shortcut of computers) by the end of the 19th century. And a little magazine called Scientific American published an article on the phenomenon back in 1959 that holds up today.
Even back then, the rudimentary outlines of the much-maligned "hockey stick" were visible, showing human-induced warming temperatures over time, despite the fact that U.S. geochemist Charles Keeling had only begun his annual measurements of carbon dioxide (CO2) levels in the atmosphere in Hawaii a year earlier. And the outcome was clear: average global temperatures would rise much the way that a closed car heats up in the sun.
Deadline: Jan 11 2014
Reward: $20,000 USD
Conventional washing machines cause excessive damage and wrinkling to clothes primarily during the water removal step. With the introduc
Deadline: Jan 27 2014
Reward: $15,000 USD
The Dow Chemical Company is the leading producer of polyalkylene glycols (PAGs) used in synthetic fluids and lubricants where petroleum,
Give a 1 year subscription as low as $14.99X