Roentgen (unit) Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. In 1928 it was the first international measurement quantity for ionising radiation to be defined for radiation protection, and was an easily replicated method of measuring air ionization directly by using an ion chamber. It is named after the German physicist Wilhelm Röntgen, who discovered X-rays. Although relatively easy to measure, it had
Kaiser Wilhelm II Land 370 metre high extinct volcano which was named after the mathematician and physicist Carl Friedrich Gauss. Kaiser Wilhelm II Land Kaiser Wilhelm II Land (also Wilhelm II Coast) is the part of Antarctica lying between Cape Penck, at 87°43'E, and Cape Filchner, at 91°54'E and is claimed as part of the Australian Antarctic Territory, although this claim is not universally recognized. The area was discovered on February 22, 1902 during the Gauss expedition (1901-1903), led by Arctic veteran and geology professor Erich von Drygalski. Drygalski named it after Kaiser Wilhelm II who had funded the expedition with 1.2 million Goldmarks.