History Time Line Hall of Fame		History : Hall of Fame Learn a little about their lives and contributions.  Please click on a name for more information. (Many of the biographies are copyrighted by the Health Physics Society.) Henri Becquerel Discovered X-rays Niels Bohr Provided the theory of Rutherford's model of atom James Chadwick Proved the existence of the neutron Arthur Holly Compton Provided characteristics of electromagnetic radiation William David Coolidge Invented the Coolidge X-ray tube Marie and Pierre Curie Discovered radiation Thomas Alva Edison Improved screens used to see X-rays Albert Einstein Developed theory about relationship of mass and energy Robley Evans Built the first whole body counter to measure radium uptake Gioacchino Failla Improved medical applications of radiation Enrico Fermi Performed first controlled self-sustaining nuclear chain reaction Otto Hahn Discovered nuclear fission Victor F. Hess Discovered cosmic rays Frédéric and Irène Joliot-Curie Discovered artificial radioactivity Ernest O. Lawrence Invented the cyclotron Lise Meitner Assisted Hahn in discovering fission Hermann Joseph Muller Father of radiation genetics Herbert Parker Developed the Manchester System for radium therapy Edith Quimby Determined distribution of radiation doses in tissue from various arrangements of radium needles Wilhelm Conrad Röntgen Discovered X-rays Ernest Rutherford Father of nuclear physics: named and characterized alpha, beta and gamma particle Glenn Seaborg Discovered (or co-discovered) the elements plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium and nobelium, as well as a wide variety of radionuclides including iodine-131, technetium-99m, cobalt-60, cesium-137, and iron-55 Frederick Soddy Establishes theory of nuclear reactions (with Rutherford) Joseph John Thomson Discovered the electron George von Hevesy Conceived the idea of using radioactive tracers