Today’s Wonder of the Day was inspired by Fabrizio from AL. Fabrizio Wonders, “How do X-rays work” Thanks for WONDERing with us, Fabrizio!

What do penicillin, Super Glue and X-rays have in common? Their inventors all discovered them by accident!

In 1895, German physicist Wilhelm Roentgen was experimenting with electricity in a special tube. He wanted to find out how electricity would act in a vacuum. For that reason, Roentgen removed as much air from the tube as possible. That allowed electrons to move at a very fast pace through the tube.

As the electrons moved, they bumped into each other. They also ran into the glass of the tube and two special parts of the tube called the cathode and anode. What Roentgen didn’t know was that, when these fast-paced electrons bumped into the tube’s anode, they would send off a type of light that hadn’t yet been discovered. This type of light is called an x-ray.

X-rays are a type of light ray, much like the visible light we see every day. The difference between visible light and x-rays is the wavelength of the rays. Human eyes cannot see light with longer wavelengths, such as radio waves, or light with shorter wavelengths, such as x-rays.

Soon, Roentgen noticed that a fluorescent screen in his lab started glowing while he conducted his experiment. While he knew fluorescent material normally glows when exposed to electromagnetic radiation, he was still surprised because heavy cardboard, which he thought would have blocked the radiation, surrounded the tube.

He began to experiment by placing different objects between the tube and the screen. No matter what he put between the two, the screen still glowed.

At one point, Roentgen placed his hand in front of the tube. When he did this, he saw a silhouette of his bones projected onto the screen.

Not only had Roentgen discovered x-rays, he saw firsthand (pun intended!) how they could become extremely helpful to medicine.

There’s no doubt the x-ray machine is very useful to doctors. X-rays can pass through nonmetallic objects, including human tissues and organs. An x-ray machine is like a giant camera that allows doctors to see what is going on inside a patient without having to do surgery.

It took a long time for scientists to make the x-ray safe for medical use. Today’s x-ray machines produce a stream of electromagnetic radiation that interacts with an anode in an x-ray tube. The x-rays made by this interaction are then directed toward the part of the body being examined. To reduce radiation exposure, x-ray machines aim the x-rays at only the focus area.  

When x-rays come into contact with our body tissues, they produce an image on a metal film. Soft tissue, such as skin and organs, cannot absorb the high-energy rays, and the beam passes through them. Dense materials inside our bodies, like bones, absorb the radiation.

Much like camera film, the X-ray film develops depending on which areas were exposed to the X-rays. Black areas on an x-ray represent areas where the x-rays have passed through soft tissues. White areas show where denser tissues, such as bones, have absorbed the x-rays.

Have you ever had an x-ray? They’re commonly used to see broken bones. Doctors might also order an x-ray when trying to figure out why you don’t feel well. But rest assured! X-rays are nothing to be nervous about. They don’t hurt at all. Instead, they help doctors find ways to make you feel better.

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Watch your step! The forecast calls for ice in Wonderopolis tomorrow. You may want to take tomorrow’s Wonder of the Day with a grain of salt.