Lighting technology began to be developed tens of thousands of years ago, and continues to be refined in the present day. Physics professor Wilhelm Roentgen, in Wurzburg changed the course of medicine when he discovered X-rays, energy waves at frequencies from 0.1 – 10 nanometers. In November 1895, he was experimenting an electron- discharge tube covered with black cardboard, he noticed that a fluorescent screen was illuminated. After fraction of seconds he realized the tube which emitted ray- marked X for unknown which was blocked by a dense objects, lik lead or bones, but could not penetrate other objects.
A new form of radiation was discovered in 1895 by Wilhelm Roentgen, a German physicist. He called it X-radiation to denote its unknown nature. This radiation had the ability to pass through many materials that absorb visible light. X-rays also have the ability to knock electrons loose from atoms.
X-radiation is a form of electromagnetic radiation. Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 100 eV to 100 keV.
There is no universal consensus for a definition distinguishing between X-rays and gamma rays. One common practice is to distinguish between the two types of radiation based on their source: X-rays are emitted by electrons, while gamma rays are emitted by the atomic nucleus. Over the years these exceptional properties have made X-rays useful in many fields, such as medicine and research into the nature of the atom.