Keyword: diffraction

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  • We donít need no intuition

    12/06/2012 1:38:10 AM PST · by neverdem · 2 replies
    Chemistry World ^ | 5 December 2012 | Neil Withers
    US scientists have developed a way to solve crystal structures that combines powerful computational methods with data from experiments or databases ¬Ė but that does not require much human input. Previous computational methods to predict structures rarely use experimental data, take a long time and are limited to compounds with small unit cells. They also give structures that generally have lower symmetry than those which have been experimentally determined, suggesting that the answers may not be quite right.¬ĎOne of the dirty little secrets that people don¬ít generally talk about is that, with a lot of these methods, you always...
  • Simple 'superlens' sharpens focusing power

    04/25/2008 12:45:54 AM PDT · by LibWhacker · 3 replies · 132+ views
    New Scientist ^ | 4/24/08 | Mason Inman
    A simple-to-make "superlens" can focus 10 times more sharply than a conventional lens. It could shrink the size of features on computer chips, or help power gadgets without wires. No matter how powerful a conventional lens, it cannot focus light down to more than about half its wavelength, the "diffraction limit". This limits the amount of data that can be stored on a CD, and the size of features on computer chips. Researchers have devised ways to beat the diffraction limit before, using bizarre "metamaterials" that are hard to make, and which are also the basis of prototype "invisibility cloaks"....
  • Astronomy Picture of the Day 3-11-03

    03/11/2003 3:26:03 AM PST · by petuniasevan · 12 replies · 262+ views
    NASA ^ | 3-11-03 | Robert Nemiroff and Jerry Bonnell
    Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 March 11 Iridescent Clouds Credit & Copyright: Arne Danielsen Explanation: Why would clouds appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. These clouds are formed of small water droplets of nearly uniform size. When the Sun is in the right position and mostly hidden by thick clouds, these thinner clouds...
  • New Method May Catch Killer Breast Cancer Earlier

    02/19/2003 2:34:29 PM PST · by NormsRevenge · 303+ views
    Yahoo! News ^ | 2/19/03 | Reuters - London
    LONDON (Reuters) - A new screening technique being developed by scientists in England may help turn the tables on breast cancer by identifying tumors far earlier. Breast cancer is one of the biggest killers of women across the world, accounting for more than 43,000 deaths a year in the United States and 13,000 in Britain alone. As with all cancers, early detection is key to enhanced survival rates. Currently mammograms can only detect tumors when they have grown to between 10 and 12 millimeters across, but New Scientist magazine reported that a technique being developed at University College London can...