ABSTRACT
In 1895, the German physicist Wilhelm Röntgen was studying the behavior of streams of electrons emitted from negatively charged electrodes, called cathode rays. He wanted to investigate the luminescence caused when cathode rays struck samples of various chemicals. In his experiments, Röntgen recognized that a new kind of radiation was emerging from the cathode-ray tube. This newly discovered radiation could pass through thick paper and even through thin layers of metals. At first, this new form of radiation was called ‘Röntgen rays’ in honor of the discoverer, but Röntgen himself used the universal mathematical symbol of the unknown, calling the radiation ‘X-rays.’
