Overview
X-rays are a form of electromagnetic radiation with wavelengths shorter than ultraviolet light but longer than gamma rays, typically ranging from 10 nanometers to 10 picometers. Their high energy allows them to penetrate materials, making them invaluable for imaging internal structures. Discovered accidentally in 1895, X-rays revolutionized medicine by enabling non-invasive visualization of bones and organs. Today, they are also critical in fields like astronomy, materials science, and security scanning.X-rays are produced when high-energy electrons collide with a metal target, releasing photons via bremsstrahlung (braking radiation) or characteristic X-rays from atomic transitions. Their ability to ionize atoms also makes them useful in cancer treatment (radiotherapy) but necessitates careful handling to avoid biological harm.
History/Background
Wilhelm Röntgen, a German physicist, discovered X-rays on November 8, 1895, while experimenting with cathode rays in a vacuum tube at the University of Würzburg. He noticed that a fluorescent screen in his lab glowed despite being shielded from visible light, leading him to conclude that an unknown "ray" was passing through the glass. On December 22, 1895, he took the first X-ray image of his wife’s hand, revealing her bones and a ring—a groundbreaking demonstration of the technology’s potential.By 1896, physicians began using X-rays for medical diagnostics, though their risks were poorly understood. The 20th century saw rapid advancements: 1912 marked the birth of X-ray crystallography, pioneered by Max von Laue, which unlocked atomic structures. In 1970, Godfrey Hounsfield developed the first computed tomography (CT) scanner, layering X-ray data to create 3D images. Röntgen was awarded the first Nobel Prize in Physics (1901) for his discovery.
