Experimental physicist — Philipp Lenard (Pressburg 1862 – Messelhausen 1947) was a Hungarian-born German experimental physicist, among the foremost researchers of cathode rays. Trained under Heinrich Hertz, whose assistant he was, he taught at several German universities, including Heidelberg. He devised a tube with a thin aluminium window that allowed cathode rays (electrons) to exit into the air, enabling their detailed study. His measurements on the photoelectric effect showed that the energy of the emitted electrons depends on the frequency of the light and not on its intensity, a result later explained by Einstein with light quanta. He received the Nobel Prize in Physics in 1905 for his research on cathode rays.
Fun fact
He became a fierce nationalist and antisemite: he championed the so-called «German physics» and publicly attacked Einstein and relativity, gravely tarnishing his scientific legacy.
Theories and contributions
- Study of cathode rays — With the Lenard window he was able to extract and study cathode rays (electrons) outside the tube, clarifying their properties.
- Observations on the photoelectric effect — The energy of the emitted electrons depends on the frequency of the light, not on its intensity: a fact later explained by Einstein.
Present in chapters
Linked atoms
1 linked atom.