Profs. Lenard and Einstein and Dr. Seuss

Philipp Lenard (1862-1947) was a brilliant experimental physicist who won the Nobel Prize in 1905 for his work on cathode rays. He was also an anti-Semite and racist, who devoted the second half of his life to purging physics from Jewish and other "degenerate" influences (particularly from Einstein) and became the chief science advisor to Hitler. Recently, I checked out his book "Great Men of Science" (published in 1929, published in English a few years later) from Caltech's library, mainly to find out what Lenard had to say about Heinrich Hertz, his mentor. Hertz, an even more famous German physicist, had Jewish ancestry, and while he died early, his family had to leave Germany when Hitler came to power. The book turned out to be an interesting read. Although Lenard only mentions Hertz's ancestry in passing, he has a lot to say about the reasons for the lack of scientific progress in the Middle Ages. First of all, he dismisses all Arab contributions as not important, and then goes on to say: 

"We now regard it as proved that the original habitation of races fitted for such achievement is the north of Europe, where they had been developed through many generations in the hard school of the Glacial Period. It is from there that the ancient Greeks had come... But their posterity began to degenerate. ... Their race did not leave descendants, but was hopelessly ruined by the influx of Asiatic and African elements.... It was necessary that new men from the North, the only home on earth of the seekers and bringers of light, should again come southward... The healing effect of the passage of centuries, which allowed men of sufficient purity of blood again to reach dominance was first seen in two events... Gutenberg invented printing in the year 1440. Columbus in 1492 began his bold and protracted journey to the West..."

Also of interest is the last chapter, about Friedrich Hasenohrl. Friedrich who? According to Lenard, he is the German physicist who showed the equivalence of mass and energy. More precisely, he showed that for a radiation in a cavity E=3/4 mc^2, but Lenard says in a footnote that probably there is some subtlety in the derivation, and the actual formula is more likely to be E=mc^2. Einstein is not even mentioned. 

What does Dr, Seuss have to do with this? Well, Seuss had slightly racist pictures in a couple of his books, and those books have been essentially banned (the publisher discontinued them and many online stores, like eBay, no longer allow people to sell them either). Compared to this, Lenard's book is not just racist. It is a product of a Nazi worldview. But would it be good if it were banned? Definitely not. At the very least, it is of great historic interest. Is there danger that someone who is not familiar with the subject would conclude that it was Hasenohrl, not Einstein, who discovered E=mc^2? Perhaps, but it is fairly easy to fix this: in any future edition one could simply add an introduction explaining the background. In any case, if the reader has any interest in the true state of affairs, he will quickly find out that Lenard's interpretation is completely bogus. And if the reader is not interested in truth, then it does not matter if Lenard's book is available to him or not. I am glad it is available to me though.