Wilhelm Conrad Roentgen was a German physicist who discovered X-rays in 1895. He produced X-rays using a cathode ray tube coated with a fluorescent substance. This allowed him to observe effects that could not be explained by known scientific effects. Roentgen studied his discovery systematically and found medical uses for X-rays. His discovery revolutionized medicine and established the field of radiology. Roentgen received the first Nobel Prize in Physics in 1901 in recognition of his achievement.