X-rays are electromagnetic waves of short length, ie, light rays are not visible to the naked eye. They consist of atomic particles and are emitted from cathode ray tubes. One of the most important virtues of this type of rays that can penetrate is opaque to light, and therefore allow to obtain photographs of these bodies. They were discovered in 1895 by German physicist Wilhelm Röntgen, and before long were used for diagnosis in medicine. The degree of penetration of these rays depends on the density of matter. The bones, as well as metals, absorb more radiation than other body tissues or wood. They are therefore used to investigate both the strength of a wall or a metal structure as the skeleton of the human body.
Devices that emit these rays are used in the diagnosis and clinical therapy, such as X-ray equipment; in physics research, such as nuclear reaction nuclear equipment and industrial radiography, such as parts used to investigate industrial castings.
Excessive exposure of the human body X-rays cause tissue damage and may cause cancer.