NOVA Online | Death Star | Tour the Spectrum: X-ray

A Self-Guided Tour of the Electromagnetic Spectrum

X-ray
When Wilhelm Roentgen discovered X-rays in 1895, he didn't understand what they were, so he called them "X-rays." We now know that X-rays are electromagnetic waves that occupy the spectrum between ultraviolet and gamma radiation.

X-rays have myriad uses - everything from examining a person's bones to inspecting computer chips, from analyzing the structure of crystals to photographing celestial objects.

The X-ray radiograph is an invaluable tool in the field of medicine, allowing doctors to see bone and organs within the body as well as tumors, dental cavities, and other undesirables.

X-ray radiation is also used in the treatment of cancer, as it kills faster-growing cancer cells more readily than normal cells.

The extremely hot clouds of gas that surround supernova explosions are a good source of X-ray radiation. Here's an X-ray image of the supernova remnant Cassiopeia A. In this image, different X-ray wavelengths have been assigned different colors: blue = high energy wavelengths, green = medium energy, and red = low energy.

Next: Gamma Rays

intro | radio | microwave | infrared | visible light | ultraviolet | x-ray | gamma

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