X-rays are amazing things. They were invented a really long time ago. I think when they were invented, they were real, cutting edge technology. I think a lot of people were amazed they could see photos of the inside of their body. So OK, it's only photos of bones, but still, that was pretty high-tech fifty years ago. Today, we all have X-rays. Even when we go to the dentist, we have X-rays taken of our teeth. Of course, X-rays are not just used in hospitals. Every time we go to an airport we have to pass through an X-ray machine. The security guys can check to see if we have anything dangerous. Recently, I have seen X-ray machines in all kinds of places – even hotels. I even heard they are in schools.