Have you ever flown in an airplane? At the airport you must have gone through the airport security control. Every passenger has to go through a special metal gate, but that is not an X-ray machine. That thing only peeps, if you are wearing something metal like a watch, or if you have something metal in one of your pockets, like a coin.
Your index finger is the one that you point with. Take a sheet of paper and a pencil and make an “X-ray photograph” sketch of your index finger. What do you think?
Have you ever asked yourself, why is the sky BLUE? Well, for that matter, why is the sky RED sometimes?
One evening in 1895, William Röntgen sat all alone in his laboratory in Würzburg, a very old city in Germany. He was very hungry and should have been at home with his family by that time, but he could not tear himself away from his work because something strange had happened. He was conducting an experiment with light, that is, with rays that you can see. While he was carrying out this work he noticed that there are also invisible rays.