X-rays were first observed and documented in 1895 by Wilhelm Conrad Roentgen, a German scientist who found them quite by accident when experimenting with vacuum tubes.

A week later, he took an X-ray photograph of his wife's hand which clearly revealed her wedding ring and her bones. The photograph electrified the general public and aroused great scientific interest in the new form of radiation. Roentgen called it "X" to indicate it was an unknown type of radiation. The name stuck, although (over Roentgen's objections), many of his colleagues suggested calling them Roentgen rays. They are still occasionally referred to as Roentgen rays in German-speaking countries.

The Earth's atmosphere is thick enough that virtually no X-rays are able to penetrate from outer space all the way to the Earth's surface. This is good for us but also bad for astronomy - we have to put X-ray telescopes and detectors on satellites! We cannot do X-ray astronomy from the ground.

X-rays have been know to cause cancer and heart disease. Even dental X-rays can trigger heart attacks. Blood vessels are very sensitive to X-rays and are easily damaged. X-rays in a Mammogram will cause breast cancer.

Please proceed to page-2 of x-rays