9 Incredibly Fascinating Insights About X-Rays

In 1895, Wilhelm Roentgen, a Physics professor in Worzburg, Bavaria, became the first to discover a method to see inside the human body without invasive procedures. On November 8, while experimenting with electricity conduction through low-pressure gases using an induction coil and a partially-evacuated glass tube, he stumbled upon a mysterious ray that illuminated a fluorescent screen several meters away. Placing his hand between the ray and the screen, he observed the shadow of his bones. Further tests revealed that the screen could be substituted with a photographic plate, marking the birth of the x-ray. Roentgen was later awarded the first Nobel Prize in Physics for this groundbreaking discovery.

Since their discovery, x-rays have transformed medical diagnostics and significantly influenced fields like astronomy, chemistry, and other scientific disciplines. They have enabled us to explore the intricacies of our DNA and observe distant galaxies. In a 2009 poll conducted by the Science Museum of London, nearly 50,000 participants voted the x-ray as the most significant modern scientific discovery, surpassing even penicillin, which came in second.

1. THE X STANDS FOR UNKNOWN.

Roentgen referred to his groundbreaking discovery as X-strahlen—where strahlen translates to “beam” or “ray” in German, and “x” symbolizes an unknown quantity in mathematics. Despite our advanced understanding of x-rays today, their name continues to evoke a sense of mystery. They are also known as “Roentgen's rays,” and the images they generate are occasionally referred to as “roentgenograms.”

2. ONE OF THE FIRST X-RAYS CAPTURED THE HAND OF THE DISCOVERER’S WIFE.

Following the tradition of many scientists, Roentgen conducted initial experiments on his wife. Among his earliest x-rays—possibly the very first—was an image of Anna Bertha's hand, adorned with her wedding ring (shown above). Legend has it that she was far from impressed; some accounts claim she declared, “I have seen my death!” upon viewing the eerie image. (Explore other pioneering x-rays through the British Library here.)

3. THEIR PRACTICAL APPLICATION BEGAN ALMOST INSTANTLY.

Shortly after Roentgen’s announcement, European surgeons began utilizing x-rays to locate bullets and other foreign objects within the human body. One of the earliest documented cases involved a British doctor who identified a needle lodged in a woman’s hand. By the next year, the Glasgow Royal Infirmary had established an x-ray department, and the technology was being employed in the US to diagnose bone fractures and gunshot wounds.

However, not all applications were medically justified—the daughter of an early enthusiast later recalled, “at one of my birthday parties, we gave the children fancy rings and showed them their skeletal hands, eliciting loud shrieks of excitement. Knowing what we do today, he certainly wouldn’t have done it.”

4. EARLY BELIEFS HELD THAT X-RAYS WERE COMPLETELY SAFE.

Initially, it was believed that x-rays passed through the body as harmlessly as ordinary light. This perception changed after Thomas Edison’s assistant, Clarence Dally, who had extensive exposure to x-rays, died of skin cancer in 1904. This tragedy prompted serious consideration of the health risks associated with the technology.

Partly due to the belief in their safety—but largely because of their novelty—x-ray machines became a trend in the late 19th and early 20th centuries. They appeared at carnivals and theatrical shows as curiosities. The term “x-ray” was even used as a marketing tactic for products like headache pills and stove polish, fueling a brief period of “x-ray mania” that saw the rays featured in advertisements, songs, and cartoons.

From the 1930s through the early 1950s, x-ray machines were commonly found in American shoe stores to ensure a perfect fit. A demonstration of this practice can be seen in this clip from the 1920s silent film, General Personal Hygiene:

5. X-RAYS TRANSFORMED THE APPROACH TO TUBERCULOSIS TREATMENT.

Before antibiotics became available for tuberculosis in the mid-20th century, the primary treatment for TB was rest in a sanatorium. Early detection was believed to be crucial for effective treatment, but traditional diagnostic methods, such as listening to chest sounds, were often unreliable. X-rays enabled doctors to identify the distinctive shadows and spots on the lungs caused by M. tuberculosis bacteria. This led to the widespread use of mass radiography in armies, factories, and mines, saving countless lives.

6. X-RAYS HAVE THE POWER TO COMBAT CANCER.

Early researchers observed that x-rays could cause skin burns, a problem exacerbated by the high radiation doses emitted by older machines. While excessive exposure to x-rays can lead to cancer, they can also be used to treat it. As far back as Roentgen’s time, doctors employed x-rays to remove moles. Today, in addition to their diagnostic uses, precisely targeted x-ray beams are utilized in radiotherapy to destroy cancerous tissues.

7. X-RAYS PLAYED A CRUCIAL ROLE IN DISCOVERING DNA’S STRUCTURE.

The discovery of DNA’s double-helix structure was significantly aided by x-ray crystallography—a method where x-rays reflect off the atomic arrangement within a crystal to create a shadow image of its structure. In the early 1950s, British scientist Rosalind Franklin captured the x-ray images that first revealed DNA’s shape. Unfortunately, she passed away before she could share the Nobel Prize with James Watson and Francis Crick, who are often credited with uncovering the “secret of life.”

8. X-RAYS HAVE ENABLED US TO EXPLORE THE COSMOS

Over a dozen x-ray-detecting telescopes have been sent into space, enabling discoveries far beyond our solar system. In 1999, NASA launched the Chandra X-ray Observatory aboard the Space Shuttle Columbia. Since then, it has identified black holes, enhanced our knowledge of dark matter, and examined the massive black hole at the Milky Way’s center, among other accomplishments.

9. X-RAYS HAVE REVOLUTIONIZED OUR PERSPECTIVE ON ART AND ARTIFACTS.

X-rays have enabled researchers and art experts to uncover “underpaintings”—the preliminary sketches artists used to outline their masterpieces—along with other hidden details. These discoveries provide art historians with deeper insights into the techniques and processes employed by artists in the past. Additionally, x-rays reveal how artworks have been altered or restored over the years, often leading to more accurate and authentic preservation efforts.

X-rays have also been instrumental in examining invaluable artifacts, such as Egyptian mummies, without causing any harm. They have unveiled unexpected findings, like the human remains concealed within a Chinese statue. Furthermore, x-rays have been used to explore the contents of opaque amber, revealing otherwise hidden fossils of ancient creatures, insects, and plant life.