When a passenger puts their bags through an X-ray machine, they go through a
type of electromagnetic energy. Unlike visible light, humans cannot see X-rays. In
hospitals, these X-ray energy beams can see through skin tissue to detect broken
bones, tumors or other injuries. In an airport, X-ray technology is used in CT
(computer tomography) scanners. Suitcases from passengers ride along a
conveyor belt and pass through the hollow CT scanning machines. The X-rays
bounce off the objects inside the suitcases, measuring the density and mass of
each object. All that data is immediately entered into a computer. CT scanners are
more complex than metal detectors and can analyze chemical components in
addition to metallic objects. If the density and mass of items in the suitcase match