How are X Rays used in Medical Diagnosis?
X-Rays will be partly absorbed and scattered by the material they pass through, and different materials will absorb/scatter X-Rays by different amounts. This is the same sort of thing that happens when light passes through different kinds of liquid or glass or anything transparent — water allows almost all the light to pass through, apple juice absorbes a little bit of light, black coffee absorbes most of the light (assume the same sized glass container for all three cases). If we were given a glass sculpture and told that inside the sculpture there were different kinds of glass, then all we would have to do is to hold the sculpture up to a source of light to see the different internal glass parts, since they would affect the light differently. This is what a standard X-ray does when a human body is placed in between an X-ray source and a photographic film that is sensitive to X-rays. A fluoroscope uses a sort-of digital video camera in place of the film, and so it can watch things mo
