The search engine Google is featuring a radioactive doodle today to celebrate the 115th anniversary of the x-ray's discovery.
On 8 November 1895, exactly 115 years ago, German physicist Wilhelm Roentgen discovered the x-ray image while experimenting with a Crookes tube in his laboratory. Despite being shielded by heavy cardboard, the Crookes tube (a glass gas bulb that emits a fluorescent light when conducting a high-voltage current) cast a green glow on a screen nine feet away.
Not knowing what to call this new ray, Roentgen labeled it with an "X."
The Google doodle is a good reminder of the value of x-rays to modern life. Not only are they used for medical and dental purposes, but also for checking the structural integrity of buildings, finding hidden layers in priceless paintings, detecting new sources of radiation in space, and security screening.