X-ray machines are used in health care for visualising bone structures and other dense tissues such as tumours. Non-medicial applications include security and material analysis.
X-rays are highly penetrating, ionizing radiation, therefore X-ray machines are used to take pictures of dense tissues such as bones and teeth. This is because bones absorb the radiation more than the less dense soft tissue. X-rays from a source pass through the body and onto a photographic cassette.
Areas where radiation is absorbed show up as lighter shades of grey (closer to white). This can be used to diagnose broken or fractured bones. In fluoroscopy, imaging of the digestive tract is done with the help of a radiocontrast agent such as barium sulfate, which is opaque to X-rays.
After WWI, X-Rays had become commonplace, as did a new way of thinking about sexuality.