X-rays were invented in 1895 by a German physicist named Wilhelm Conrad Röntgen. He discovered x-rays at the University of Würzburg while experimenting with electron beams in a gas discharge tube. He noticed that a fluorescent screen in his laboratory began to glow when the tube was turned on. This surprised him because he thought that the heavy cardboard surrounding the tube would catch most of the radiation. This shows that x-rays penetrate most materials. Röntgen began to place different things between the tube and the screen, but none of them stopped the screen from glowing. Finally, he placed his hand in between the tube and the screen and the silhouette of his bones was shown on the screen. He had discovered the most useful application for x-rays. His first four photographs included the hand of his wife (picture below), a set of weights, a compass, and a piece of metal, which he included in his paper, "On a New Kind of Rays," published December 28, 1895. He published a total of three papers between 1895 and 1897 and none of his conclusions have yet been proven false. In 1901, he won the first Nobel Prize for Physics. Röntgen's discovery was one of the most remarkable discoveries in medical history. X-rays allow doctors to look directly through tissues and see broken bones, cavities, and swallowed objects with ease. X-rays can also be used to examine soft tissues.
Röntgen's had Twelve Discoveries that are still relevant today. X-rays:
Are highly penetrating, invisible rays which are a form of electromagnetic radiation.
Are electrically neutral and therefore not affected by either electric or magnetic fields.
Can be produced over a wide variety of energies and wavelengths (polyenergetic and heterogeneous).
Release very small amounts of heat upon passing through matter.
Travel in straight lines.
Travel at the speed of light, 3.00x108 m/s in a vacuum.
Can ionize matter.
Cause fluorescence (the emission of light) of certain crystals.
Cannot be focused by a lens.
Affect photographic film.
Produce chemical and biological changes in matter through ionization and excitation.
Produce secondary and scatter radiation.