115th Anniversary of the Discovery of X-rays

Source: http://www.google.com.vn/logos/2010/xraydiscovery2010-ps.gif

X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 × 10¹⁶ Hz to 3 × 10¹⁹ Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Conrad Röntgen, who is generally credited as their discoverer, and who had named them X-rays to signify an unknown type of radiation.: Correct spelling of X-ray(s) in the English language includes the variants x-ray(s) and X ray(s). XRAY is used as a communications code word for the letter x. [Read more on Wikipedia]