November 8, 2010 is the 115th anniversary of the discovery of X-rays. Google will have a special logo, aka Doodle, of an X-ray of the Google logo.
Now you can check out Google’s new Doodle logo when you open Google homepage which is made up of bones, a key, a rubber duck, other skeletons and maybe a couple coins. To celebrate the 115th anniversary of the discovery of X-ray Google just revealed this logo.
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 tofrequencies 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.
X-ray was Discovered by German physicist Wilhelm Röntgen is usually credited as the discoverer of X-rays because he was the first to systematically study them, though he is not the first to have observed their effects. He is also the one who gave them the name “X-rays“, though many referred to these as “Röntgen rays” for several decades after their discovery and to this day in some languages, including Röntgen’s native German, and Swedish.
X-rays were found emanating from Crookes tubes, experimental discharge tubes invented around 1875, by scientists investigating the cathode rays, that is energeticelectron beams, that were first created in the tubes. Crookes tubes created free electrons by ionization of the residual air in the tube by a high DC voltage of anywhere between a few kilovolts and 100 kV. This voltage accelerated the electrons coming from the cathode to a high enough velocity that they created X-rays when they struck the anode or the glass wall of the tube. Many of the early Crookes tubes undoubtedly radiated X-rays, because early researchers noticed effects that were attributable to them, as detailed below. Wilhelm Röntgen was the first to systematically study them, in 1895.
Source : http://en.wikipedia.org/wiki/X-ray