In 1895 German physicist Wilhelm Rontgen experimented with a cathode ray tube in his darkened laboratory when he noticed something unexpected. A screen coated with a special fluorescent chemical began glowing even though the tube was completely covered with heavy black cardboard that should have blocked any light. Rontgen concluded that some unknown invisible ray was passing through the barrier and named them X-rays. To test his theory he had his wife Anna Bertha place her hand in the beam and c