Wilhelm Conrad Roentgen, German experimental physicist. Born in Lennep on March 27, 1845, he graduated from the Department of Mechanical Engineering at the Federal University of Technology in Zurich in 1868. Received a doctorate from the University of Zurich in 1869.

On November 8, 1895, Roentgen discovered X-rays while conducting cathode ray experiments. X means unknown. On January 23, 1896, Roentgen gave his first report at his institute; at the end of the report, a photo of the hand of Kricker, a famous anatomy professor at the University of Würzburg, was taken with X-rays; Kricker took the lead in cheering Roentgen three times and suggested naming this ray as a Roentgen ray. The Nobel Prize was first awarded in 1901, and Roentgen won the Physics Prize that year for this discovery.

Roentgen rays were the first so-called "penetrating rays" to be discovered, penetrating certain materials that ordinary light could not.

Rector of the University of Würzburg in 1894, Professor of Physics and Director of the Institute of Physics at the University of Munich in 1900. Died in Munich on February 10, 1923.