Wednesday, December 28, 2011

Scientist of the Week: George de Hevesy

George de Hevesy

Ok, so last week's scientist was Neils Bohr, and there was probably a good amount of you that have heard of him. This week's scientist is George de Hevesy. My guess is that most of you have not heard of George de Hevesy, but I guarantee his story is one you'll be repeating at the next party you're at...if it's like a Lord of the Rings marathon kind of party. But first a quick bio:

Hevesy was a radiochemist who won a Nobel prize in 1943 for his work on radioactive tracers (In short, you inject something radioactive into anything living and you can follow reaction pathways or see how long a given reaction takes - Hevesy was studying metabolism). As part of this work he discovered hafnium (element 72), an important element used in nuclear reactors. He studied under Ernest Rutherford and was a life-long professor of Physical Chemistry - the most interesting of all the fields of chemistry1.

But the story I want to tell you about is this:

During WWII, Germany wasn't exactly a refuge for scientists. This was especially the case for Max von Laue (who helped his Jewish colleagues escape from Germany) and James Franck (a Jewish scientist living in Germany). Each had, at separate times, received a Nobel prize.

Worrying that the gold Nobel prize medals would be forcibly taken from them, George de Hevesy devised an ingenious plan to protect them - he dissolved them in acid. Hevesy dissolved both medals in a beaker of aqua regia, a very potent acid2. He then stored the beaker in his lab at the Neils Bohr Institute3 until the end of the war. To any prying eyes it would look like an old beaker filled with an unknown solution - something you would find in the laboratory of any Hollywood chemist.  Once he knew it was safe he precipitated the gold from the solution and returned it to the Nobel society where the medals were re-cast using the original gold.

While you could say that the medals were just things - the real honor is in being given the prize, not owning the prize itself - I think Hevesy's actions made an important point. The medals represented something more than Franck's work on electron motion or Laue's work on X-ray crystallography. The Nazis mocked Jewish scientists (calling Einstein's theory of relativity "Jewish Physics"). By protecting the medals he was protecting the reputation of Franck and Laue, protecting the reputation of other Jewish scientists (including himself), and taking his own personal stand against the Nazis.

Now, on a much less serious note, here's a comic from Zach Weiner on the subject:

[1] This is not an opinion. Gilbert Lewis once stated that Physical Chemistry is "the study of all things interesting!" I take the definition on his authority, even if his dot structures are overused by organic chemists.
[2] Aqua regia means "royal water" and is made by mixing nitric acid with hydrochloric acid. Interestingly, while the acid can easily dissolve both gold and platinum neither nitric nor hydrochloric acid is capable of this on its own.
[3] If Hevesy had been found to be transporting gold out of Germany he would have been severely punished. Luckily gold doesn't look the same when it's been dissolved.