Who Discovered X-Rays?

By: Josh Briggs  | 
A doctor speculates on X-ray images of a patient's lungs
Who figured out how to look at our bones without cutting us open? Someone with a Crookes tube and a limited (but well-intentioned!) understanding of radiation exposure. warodom changyencham / Getty Images

Have you ever had an X-ray taken of a broken bone? X-rays are invisible rays used to analyze bones, teeth, blood vessels and organs in the human body; to detect cracks in metal in industry; and even at airports for luggage inspection.

Yet, despite their versatility and penetrating power, the invention of the X-ray wasn't intentional. So, who discovered x-rays?


The Accidental Discovery of X-Rays

The scientific and medical communities will forever be indebted to an accidental discovery made by German physicist Wilhelm Conrad Röntgen in 1895. Röntgen originally set out to research the electrical charges or cathode rays created in vacuum tubes known as Crookes tubes.

While experimenting with electrical currents through glass cathode-ray tubes, Röntgen discovered that a piece of barium platinocyanide glowed even though the discharge tube was encased in thick black cardboard and was across the room [source: Britannica].


He theorized that some kind of radiation must be traveling in the space. Röntgen didn't fully understand his new discovery, so he dubbed it X-radiation for its unexplained nature.

The First X-Ray Image

To test his newfound theory, Röntgen enlisted the help of his wife, Anna Bertha Ludwig, for his first X-ray photos and captured images of the bones in her hand and her wedding ring in what would become known as the first röntgenogram, or X-ray photograph [source: Nobel Prize].

He discovered that when emitted in complete darkness, X-rays passed through objects of varying density, rendering the flesh and muscle of his wife's hand mostly transparent.


The denser bones and the ring left behind a shadow on a special photographic plate covered in barium platinocyanide. The term X-radiation or X-ray stuck, although it is still sometimes referred to as Röntgen radiation in German-speaking countries [source: NASA].

Portrait of Wilhelm Conrad Röntgen, German physicist and discoverer of the X-ray, in 1895.
Hulton Archive/Getty Images


Medical Imaging and Legacy

Röntgen's work garnered much attention in the scientific community and with the public. He gave his first public lecture on X-ray radiation in January 1896 and showed the new rays' ability to photograph the bones within living human tissue. A few weeks later in Canada, X-ray images were used to find a bullet in a patient's leg [source: Taming the Rays].

An honorary degree in medicine, medals, streets named in his honor and memberships to academic societies all followed. The recognition peaked with the awarding of the first Nobel Prize for physics in 1901 [source: Nobel Prize].


Röntgen deliberately didn't patent his discovery, feeling that scientific advances belonged to the world and should not be for profit. He also donated his Nobel Prize money to his university.

Röntgen's discovery led to major advances in science and medicine, like the development of magnetic resonance imaging (MRI) and computed tomography (CT).


Lots More Information

Related Articles

  • Britannica. "Wilhelm Conrad Röntgen." (Dec. 27, 2010) http://www.britannica.com/EBchecked/topic/509157/Wilhelm-Conrad-Rontgen
  • CBS News. "The X-Ray's Inventor Gets a Google Doodle." Nov. 8, 2010. (Dec. 27, 2010) http://www.cbsnews.com/8301-501465_162-20022116-501465.html
  • Dupont.com. "Dupont Fluoropolymer Solutions A Brief History of Fluoropolymers." (Dec. 27, 2010) http://www2.dupont.com/Teflon_Plunkett/en_US/assets/downloads/k20165.pdf
  • NASA. "X-rays." (Dec. 27, 2010)http://science.hq.nasa.gov/kids/imagers/ems/xrays.html
  • Nobel Prize. "The Nobel Prize in Physics 1901 Wilhelm Conrad Röntgen." (Dec. 28, 2010) http://nobelprize.org/nobel_prizes/physics/laureates/1901/rontgen-bio.html
  • Taming the Rays. "The Early Years of X-Rays". (Jan. 13, 2011)http://tamingtherays.com/TTR3-EarlyYearsofXrayspdf.pdf