Key Points
Learn how x-rays were discovered and their importance over time.
On November 8, 1895, physicist Wilhelm Conrad Röntgen (1845-1923) becomes the first person to observe X-rays, a significant scientific advancement that would ultimately benefit a variety of fields, most of all medicine, by making the invisible visible.
Röntgen’s discovery occurred accidentally in his Wurzburg, Germany, lab, where he was testing whether cathode rays could pass through glass when he noticed a glow coming from a nearby chemically coated screen. He dubbed the rays that caused this glow X-rays because of their unknown nature.
Medical Miracle
X-rays are electromagnetic energy waves that act similarly to light rays but at wavelengths approximately 1,000 times shorter than those of light. Röntgen conducted a series of experiments to better understand his discovery. He learned that X-rays penetrate human flesh but not higher-density substances such as bone or lead and that they can be photographed.
Röntgen’s discovery was labeled a medical miracle and X-rays soon became an important diagnostic tool in medicine, allowing doctors to see inside the human body for the first time without surgery.
Other Uses
In 1897, X-rays were first used on a military battlefield to find bullets and broken bones inside wounded soldiers.
Prior to 1912, X-rays were used little outside the realms of medicine and dentistry, though some X-ray pictures of metals were produced. High vacuum X-ray tubes designed by Coolidge in 1913 became available to use in industrial applications.
In 1922, industrial radiography took another step forward with the arrival of the 200,000-volt X-ray tube that allowed radiographs of thick steel parts to be produced in a reasonable amount of time.
General Electric Company developed 1,000,000 volt X-ray generators in 1931, providing an effective tool for industrial radiography. That same year, the American Society of Mechanical Engineers (ASME) permitted X-ray approval of fusion welded pressure vessels that further opened the door to industrial acceptance and use.
The Downside
Scientists were quick to realize the benefits of X-rays, but slower to comprehend the harmful effects of radiation. It was initially believed X-rays passed through flesh as harmlessly as light. However, within several years, researchers began to report cases of burns and skin damage after exposure to X-rays.
In 1904, Thomas Edison’s assistant, Clarence Dally, who had worked extensively with X-rays, died of skin cancer. Dally’s death caused some scientists to begin taking the risks of radiation more seriously.
X-rays were considered risky because these electromagnetic waves are of a high energy level and can break chemical bonds in the materials they penetrate resulting in altered structure or a change in the function of cells. Early exposures to radiation resulted in the loss of limbs and even lives. Researchers collected and documented information on the interaction of radiation and the human body. Unfortunately, much of this information was collected at great personal expense.
New understandings of medical protection for patients and staff allowed X-ray technology to integrate safely into the healthcare world. X-rays transitioned into the digital world by the 1970s, saving medical centers time, money, space, and giving them a chance to help more people.
X-Ray Usage Today
Today, X-ray technology is widely used in medicine, material analysis, and devices such as airport security scanners.
It has become a relatively safe and reliable practice for identifying broken bones, diagnosing cancer, or discovering other bodily abnormalities.