One hundred and fifteen years ago, Wilhelm Conrad Roentgen discovered the X-ray, an accident of experiments with vacuum tubes. According to NASA:
...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.
That radiograph is above. Fast forward 115 years, and Google is honoring the discovery with a doodle on its index page that, as you would expect, points to search results about the X-ray.
