The work of David Hilbert and Max Planck was crucial to the foundation of modern physics, which Werner Heisenberg and Erwin Schrödinger developed further. They were preceded by such key physicists as Hermann von Helmholtz, Joseph von Fraunhofer, and Gabriel Daniel Fahrenheit, among others. Wilhelm Conrad Röntgen discovered X-rays, an accomplishment that made him the first winner of the Nobel Prize in Physics in 1901. The Walhalla temple for "laudable and distinguished Germans", features a number of scientists, and is located east of Regensburg, in Bavaria.
Who discovered X-Rays? (If the question is unanswerable, say "unanswerable")
Wilhelm Conrad Röntgen