The history
130 years from a strange glow in a darkened lab to the digital X-rays taken billions of times a year.
In 1895 a German physicist noticed a screen glowing across his lab when it should have stayed dark. Within weeks doctors everywhere, from Birmingham to Calcutta, were photographing bones through skin. The new rays also burned and killed some of the people who used them most, so the next century was about making X-rays sharper, safer and smarter, until film gave way to pixels.
8 November 1895
X-rays discovered
Wilhelm Röntgen, Germany
22 December 1895
First X-ray picture of a human hand
Anna Bertha Röntgen, Germany
11 January 1896
First clinical use of X-rays (often cited)
John Hall-Edwards, England
23 June 1896
First successful X-ray photograph in India
Mahendralal Sircar, Calcutta
1901
First Nobel Prize in Physics
Wilhelm Röntgen, Germany
1966
First dedicated mammography machine
Charles Gros and CGR, France
1 October 1971
First CT scan of a patient
Godfrey Hounsfield, England
1983
First digital X-ray system
Fujifilm, Japan
1869 – 1895
Scientists play with glass tubes that glow when high voltage runs through thin gas. Something invisible is escaping from them, but nobody has noticed yet.
1875
c. 1869–1875
Crookes and other scientists pumped most of the air out of glass tubes and ran a high voltage through them. Invisible 'cathode rays' streamed from one end and made the glass glow green. These rays were later shown to be electrons.
Why it mattered. Every early X-ray machine was a tube like this: fast electrons hitting something hard is what makes X-rays.
1895
8 November 1895
Röntgen covered a cathode ray tube in black cardboard and darkened his lab. A screen painted with a glowing chemical lit up across the room. Something unknown was passing through the cardboard, so he called it X, the letter for an unknown.
Why it mattered. It was the discovery of a new kind of ray that could pass through things that block light.
1895
22 December 1895
Röntgen asked his wife Anna Bertha to hold her hand on a photographic plate while the rays shone through it. The picture showed the bones of her fingers and a dark ring on one of them. She is said to have exclaimed that she had seen her own death.
Why it mattered. It became the most famous image of the age and showed at once what X-rays could do for medicine.
1895 – 1912
Röntgen's discovery spreads around the world in weeks. Doctors, photographers and showmen build their own machines, often with no idea of the danger.
1895
28 December 1895
Röntgen handed in a short paper describing the rays to the Würzburg Physical-Medical Society. He mailed copies and X-ray pictures to other scientists on New Year's Day. Newspapers carried the story around the world within weeks.
Why it mattered. Because he shared everything fast and freely, labs everywhere could build their own machines.
1896
11 January 1896
Hall-Edwards X-rayed the hand of a colleague and found a needle buried under the skin. It is often called the first use of X-rays in clinical conditions. A month later he took an X-ray to guide a surgeon during an operation.
Why it mattered. Just two months after the discovery, X-rays were already helping doctors find what they could not see.
1896
3 February 1896
Eddie McCarthy broke his wrist skating on the frozen Connecticut River. The Frost brothers, a doctor and an astronomer, X-rayed it in a college physics lab. It is recorded as the first clinical X-ray made in America.
Why it mattered. It showed a broken bone clearly enough to guide treatment, the job X-rays still do most often.
1896
Edison's team tested thousands of chemicals and found that calcium tungstate glowed brightly when X-rays hit it. They built a fluoroscope: a box with a glowing screen you looked into to see bones move. Screens like this later helped expose X-ray film too.
Why it mattered. Turning invisible X-rays into visible light is still how many detectors work today.
1896
23 June 1896
Sircar, a doctor who founded the Indian Association for the Cultivation of Science, ordered an X-ray tube from Europe. His diary says his first try on 20 June was overexposed, but on 23 June he took good pictures of a frog and a coin. On 3 July he explained the new rays to an audience of more than 300 people.
Why it mattered. X-rays reached India within eight months of their discovery, the start of X-ray research in the country.
1897
Lafont, a Jesuit science teacher at St. Xavier's College, had brought a Crookes tube to Calcutta years earlier. With the photographer Pradyot Kumar Tagore he made an X-ray of the ringed right hand of Lord Elgin, the Viceroy. It was published by the Photographic Society of India in 1897.
Why it mattered. It showed that people in India were not just reading about X-rays but making skilled pictures with them.
1898
Bose built his own X-ray apparatus and boosted it with a Tesla transformer. In a letter from about February 1898 he wrote of examining a patient with a broken back, the first recorded medical use of X-rays in India. A newspaper in May 1898 described his X-ray of a human palm showing only bones.
Why it mattered. An Indian scientist had designed, built and improved his own machine within about two years of the discovery.
1899
August 1899
Fleischman studied the new science herself and opened an X-ray lab in San Francisco by 1897. She X-rayed soldiers wounded in the Spanish-American War, including one with a bullet lodged in his brain. Years of unshielded work gave her cancer, and she died in 1905.
Why it mattered. She was a pioneer of battlefield X-rays and one of the first women to die from radiation.
1901
10 December 1901
Röntgen won the very first Nobel Prize in Physics for discovering the rays. He never patented X-rays, because he felt they should benefit everyone. Biographers say the prize money went to his university in Würzburg.
Why it mattered. Refusing a patent let any company or hospital build X-ray machines, which spread them fast.
1904 – 1960
Deaths and burns teach people to respect the rays. Better tubes, grids and training make X-rays reliable, and war shows how many lives they can save.
1904
2 October 1904
Dally helped Thomas Edison test X-ray tubes and often held his own hands in the beam. His skin was badly burned, cancer followed, and doctors removed both his arms before he died. Edison was so shaken that he stopped working with X-rays.
Why it mattered. His death is widely considered the first in America from X-ray work, and it pushed people to take radiation seriously.
1913
Early gas tubes were moody and gave different X-rays every time. Coolidge used a very good vacuum and a heated tungsten wire that boiled off electrons on demand. Now the operator could set exactly how strong and how penetrating the X-rays would be.
Why it mattered. Almost every X-ray tube made since works this way.
1913
X-rays that bounce around inside the body reach the film from odd angles and blur the picture like fog. Bucky put a grid of thin lead strips in front of the film to block these stray rays. In 1920 the American radiologist Hollis Potter made the grid move during the shot so its lines vanished.
Why it mattered. Grids made X-rays of thick body parts like the chest and belly much sharper.
1914
When the First World War began, Marie Curie fitted cars with X-ray machines so surgeons near the front could find bullets and shrapnel. Soldiers called them petites Curies, little Curies. She trained 150 women to run X-ray units, and it is estimated that more than a million wounded soldiers were X-rayed during the war.
Why it mattered. It proved how many lives quick X-rays could save and trained a generation of radiographers.
1920
A shoe-fitting fluoroscope let customers look down and see the bones of their feet wiggling inside new shoes. About 10,000 were sold in the US, and they spread to Britain, Canada and beyond. Pennsylvania became the first state to ban them, in 1957, once the radiation risk was clear.
Why it mattered. It is a reminder that a new technology can become a toy before people understand its risks.
1912 – 1965
Scientists discover that crystals bend X-rays into patterns. Reading those patterns reveals where atoms sit, from salt to penicillin to DNA.
1912
Laue guessed that the neat rows of atoms in a crystal might scatter X-rays the way fine lines scatter light. Friedrich and Knipping shone X-rays through a crystal and found a pattern of spots on film. Laue won the 1914 Nobel Prize in Physics.
Why it mattered. It proved X-rays are waves, like light but far shorter, and gave scientists a way to peer at atoms.
1913
The Braggs worked out a simple rule for how X-rays bounce off layers of atoms, and built an instrument to measure it. They used it to find where the atoms sit in crystals like salt. They shared the 1915 Nobel Prize in Physics, when Lawrence was just 25.
Why it mattered. X-ray crystallography became one of the most powerful tools in chemistry, biology and materials science.
1929
Lonsdale, born in Ireland, used X-ray crystallography to prove that the benzene ring, a building block of many chemicals, is flat. Chemists had argued about its shape for decades. In 1945 she became one of the first two women elected to the Royal Society.
Why it mattered. It showed X-rays could settle arguments about the shapes of molecules.
1952
2 May 1952
Working in Franklin's lab, her student Gosling took an X-ray picture of DNA that showed a clear X-shaped pattern. It was shown to James Watson without Franklin's permission in January 1953. The pattern helped Watson and Crick work out that DNA is a double helix.
Why it mattered. An X-ray picture helped reveal the shape of the molecule that carries life's instructions.
1964
Hodgkin used X-rays to work out the structures of penicillin and vitamin B12, molecules too complicated for others to crack. She won the 1964 Nobel Prize in Chemistry. Later she also solved the structure of insulin.
Why it mattered. Knowing a medicine's exact shape helps chemists make it and improve it.
1960 – today
Special machines for breasts and baggage, computers that build 3D slices, and digital detectors that replace film while using less radiation.
1966
1965–1966
Breast tissue is soft, so ordinary X-rays show little inside it. In the United States, Robert Egan had shown how gentle, low-energy X-rays and fine-grained film could reveal small tumours. Gros designed the Senographe, the first machine made only for mammography, with a molybdenum target and a paddle that presses the breast flat.
Why it mattered. Mammography now finds breast cancers early, when they are easiest to treat.
1971
1 October 1971
Hounsfield, an engineer at EMI, built a scanner that took X-rays from many angles around the head and let a computer build a slice picture. The first patient scanned had a brain tumour, which showed up clearly. Hounsfield shared the 1979 Nobel Prize with Allan Cormack, a South African-born physicist who had worked out the maths.
Why it mattered. CT showed soft organs in slices for the first time, and it changed medicine.
1973
5 January 1973
After a wave of hijackings, US airlines had to screen every passenger and their carry-on bags from 5 January 1973. Low-dose X-ray scanners began to look inside bags on moving belts. Airports around the world soon did the same.
Why it mattered. X-rays became part of everyday travel, not only medicine.
1983
Fuji launched Fuji Computed Radiography, which used a reusable imaging plate instead of film. The plate stores the X-ray pattern, a laser reads it out, and a computer tidies up the picture. Because the plate is so sensitive, it can work with smaller doses.
Why it mattered. It was the first big step from chemical film to digital X-ray pictures.
1983
15 November 1983
The President of India set up the AERB under the Atomic Energy Act of 1962. It oversees the safe use of radiation across the country, including medical X-ray machines. Its mission is to make sure radiation does not cause undue risk to people or the environment.
Why it mattered. X-ray machines in Indian hospitals have a national safety regulator watching over them.
1997
c. 1995–2000
Engineers built flat detectors from thin layers of amorphous silicon or selenium covered in millions of tiny pixels. The first flat-panel systems appeared around 1995 and spread in the late 1990s. The picture appears on a screen within seconds, with no cassette to carry and no film to develop.
Why it mattered. Most X-ray rooms today use detectors like these.
2019
An earlier NCRP report found that Americans got about six times more medical radiation in 2006 than in the early 1980s, mostly from CT. Its 2019 report found the average had fallen between 2006 and 2016. Campaigns to use lower doses and smarter scanners were working.
Why it mattered. It showed that more imaging does not have to mean more radiation.
By the numbers
NCRP estimates: the average American's yearly dose from medical imaging rose about sixfold as CT spread, then began to fall.
Did you know?
Röntgen called his rays X because X is the letter mathematicians use for an unknown. In German they are still often called Röntgen rays.
Röntgen never patented X-rays, so anyone in the world was free to build an X-ray machine.
From the 1920s to the 1950s, shoe shops used X-ray machines so customers could watch the bones of their toes wiggle inside new shoes.
Lawrence Bragg was 25 when he shared the 1915 Nobel Prize in Physics with his father for using X-rays to see atoms in crystals.
Marie Curie learned to drive, change tyres and clean carburettors so she could run her X-ray cars in the war.
The people
1845 – 1923 · Physicist · Germany
Discovered X-rays, won the first physics Nobel and refused to patent them.
1839 – 1919 · The first person X-rayed on purpose (widely considered) · Germany
Her hand, with its ring, became the most famous early X-ray.
1833 – 1904 · Doctor and science founder · India
Founded the Indian Association for the Cultivation of Science and made India's first successful X-ray photographs.
1858 – 1937 · Physicist and biologist · India
Built an improved X-ray machine in Calcutta and used it to examine a patient in 1898.
1867 – 1905 · Radiographer · USA
Ran a pioneering X-ray lab in San Francisco and died from radiation injuries.
1867 – 1934 · Physicist and chemist · Poland and France
Put X-ray machines in cars and trained women to X-ray wounded soldiers in the First World War.
1873 – 1975 · Engineer · USA
Invented the hot-cathode tube that nearly every X-ray machine still uses.
1903 – 1971 · Crystallographer · Ireland and England
Proved the benzene ring is flat and became one of the first women in the Royal Society.
1920 – 1958 · Chemist and crystallographer · England
Her lab's X-ray picture of DNA, Photo 51, helped reveal the double helix.
1919 – 2004 · Engineer · England
Built the first CT scanner and shared the 1979 Nobel Prize for it.
Where it happened
Sources
Dates marked “c.” are approximate, and historians sometimes disagree about who was first. If you spot a mistake, tell us.
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