Philipp Lenard

118
Philipp Lenard bigraphy, stories - German physicist

Philipp Lenard : biography

June 7, 1862 – May 20, 1947

Philipp Eduard Anton von Lenard (June 7, 1862 – May 20, 1947), was a German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties. He was also an active proponent of Nazi ideology.

"Deutsche Physik"

Lenard is remembered today as a strong German nationalist who despised English physics, which he considered as having stolen its ideas from Germany. He joined the National Socialist Party before it became politically necessary or popular to do so. During the Nazi regime, he was the outspoken proponent of the idea that Germany should rely on "Deutsche Physik" and ignore what he considered the fallacious and deliberately misleading ideas of "Jewish physics", by which he meant chiefly the theories of Albert Einstein, including "the Jewish fraud" of relativity (see also Criticism of relativity theory). An advisor to Adolf Hitler, Lenard became Chief of Aryan physics under the Nazis.

Some measure of Lenard’s views on certain scientists may be deduced through examination of Lenard’s book, ‘Great Men in science, a History of scientific progress’, first published in 1933. The book was translated into English by Dr H Stafford Hatfield with an introduction by the famous scientist Edward Andrade of University College London and was widely read in schools and universities after the Second World War. The individual scientists selected for inclusion by Lenard do not include Einstein or Curie, nor of any other twentieth century scientist. Andrade noted that ‘A strong individuality like that of the writer of this book is bound to assert strongly individual judgements’. The publisher included what now appears to be an equally remarkable note on page xix of the 1954 English edition: "While Professor Lenard’s studies of the men of science who preceded him showed not only profound knowledge but also admirable balance, when it came to men of his own time he was apt to let his own strong views on contemporary matters sway his judgement. In his lifetime he would not consent to certain modifications that were proposed in the last study of the series".

Lenard retired from Heidelberg University as professor of theoretical physics in 1931. He achieved emeritus status there, but he was expelled from his post by Allied occupation forces in 1945 when he was 83. He died in 1947 in Messelhausen.

In Media

  • Lenard’s Criticism of relativity theory and his crusade against Einstein and his theories was covered in an episode of Dark Matters: Twisted But True in a segment entitled "Einstein’s Revenge".

Honours and awards

  • Royal Society Rumford Medal, 1896
  • Italian Society of Sciences Matteucci Medal, 1896
  • Franklin Institute Franklin Medal, 1932
  • Nobel Prize for Physics, 1905

Footnotes

Contributions to physics

Photoelectric investigations

As a physicist, Lenard’s major contributions were in the study of cathode rays, which he began in 1888. Prior to his work, cathode rays were produced in primitive tubes which are partially evacuated glass tubes that have metallic electrodes in them, across which a high voltage can be placed. Cathode rays were difficult to study because they were inside sealed glass tubes, difficult to access, and because the rays were in the presence of air molecules. Lenard overcame these problems by devising a method of making small metallic windows in the glass that were thick enough to be able to withstand the pressure differences, but thin enough to allow passage of the rays. Having made a window for the rays, he could pass them out into the laboratory, or, alternatively, into another chamber that was completely evacuated. He was able to conveniently detect the rays and measure their intensity by means of paper sheets coated with phosphorescent materials. These windows have come to be known as Lenard windows.

Lenard observed that the absorption of the rays was, to first order, proportional to the density of the material they were made to pass through. This appeared to contradict the idea that they were some sort of electromagnetic radiation. He also showed that the rays could pass through some inches of air of a normal density, and appeared to be scattered by it, implying that they must be particles that were even smaller than the molecules in air. He confirmed some of J.J. Thomson’s work, which ultimately arrived at the understanding that cathode rays were streams of negatively charged energetic particles. He called them quanta of electricity or for short quanta, after Helmholtz, while J.J. Thomson proposed the name corpuscles, but eventually electrons has become the everyday term. In conjunction with his and other earlier experiments on the absorption of the rays in metals, the general realization that electrons were constituent parts of the atom enabled Lenard to claim correctly that for the most part atoms consist of empty space.