Georg Placzek

This week in Mailbox we find out the name of our May mystery man as well as those of the four listeners who will receive Radio Prague prizes for their correct answers. Listeners quoted: Henk Poortvliet, Hans Verner Lollike, Charlie Cockey, Imo-Obong Umana, Jayanta Chakrabarty, Nooreddin Ahmad Hussein, Colin Law, David Eldridge, Gavin Waters, Charles Konecny.

Welcome to Mailbox. As promised, today we shall disclose the identity of our May mystery man and at the end of the programme, you’ll find out whether your name is among the lucky four who will receive Radio Prague goodies for their correct answers. So let’s have a look at some of them.

Henk Poortvliet writes from the Netherlands:

“The mystery man this month must be George Placzek, who studied physics in Prague and Vienna. Together with Otto Frisch, he suggested direct experimental proof of nuclear fission. Together with Niels Bohr and others, he was instrumental in clarifying the role of Uranium 235 for the possibility of a nuclear chain reaction. Later on he joined the Manhattan Project as mentioned by you.”

Hans Verner Lollike listens in Denmark:

“Georg Placzek is the name of the person you are looking for. He was an outstanding physicist, and worked for eight years with my countryman, Professor Niels Bohr, who later gained the Nobel Prize.”

So was Placzek’s first name George or Georg? Charlie Cockey from the Czech Republic offers the explanation later in his answer:

“The famous experiment in quantum physics that asked the question ‘is light a wave or a particle’ discovered that the correct answer is ‘yes’ – that is, light exhibits behaviour of both waves and particles. The determining factor is: what do you expect to find? If you expect a wave, it will behave like a wave; if you expect a particle, it will behave like a particle. In the same fashion the correct answer to your quiz this week depends upon what YOU expect to find. The physicist in question was born in Brno (where I now most happily live) with the name GEORG Placzek. However, in the late 1930s Georg worked with Niels Bohr, and as Hitler's Germany began devouring its neighbours he followed Bohr in 1939 to the USA, after which he was known as GEORGE – Georg with an E (presumably *not* the same 'e' that equals mc-squared.) So, depending upon YOUR expectations, the correct answer(s) is(are) Georg(e) Placzek.”

And Charlie added a postscript:

“Can you perhaps explain why his family name is spelled Placzek and not Plaček (or perhaps Pláček)? My first thought was that it was an Anglicized version, but checking Czech language sources I see it spelled with the CZ there as well. Was his family perhaps using Polish or Hungarian orthography?”

He was born into a German-speaking Jewish family, so the name is spelled according to the rules of German orthography.

Imo-Obong Umana writes from Nigeria:

“He got married to Els Placzek, the ex-wife of another physician Hans von Halban. Placzek’s work in Copenhagen rendered him a leading authority on neutron scattering and absorption in matter. In 1939, he developed a fundamental theory of neutron absorption resonances which proved essential to the subsequent development of nuclear theory and nuclear reactor design. He happened to have been the only Czech working in some leading positions in the Manhattan project both in Canada and Los Alamos before his death on October 9, 1955.”

Jayanta Chakrabarty listens to Radio Prague in India:

“An outstanding scientist of the 20th century, often referred to as the unsung hero of physics though he made notable contributions in whatever scientific realm attracted his attention. Initially Placzek worked on molecular physics and the quantum formulation of the scattering of light, popularly known as the Raman effect. But soon his deep understanding of the atomic nucleus and behaviour of neutrons in nuclear reactions attracted the attention of the authorities of the Manhattan atomic Project where he soon occupied a leading position among scientists of equally high stature.”

Nooreddin Ahmad Hussein follows our programmes in Jordan:

“I read little about this great person and I was astonished to learn that this Czech born physicist participated in the American nuclear bomb project. The Czech Republic marked two anniversaries of George Placzek in 2005: that of his birth on 26 September 1905, and that of his passing away on 9 October 1955.”

Colin Law from New Zealand supplied us with detail on Placzek’s family:

“Dr Baruch Placzek, Georg’s grandfather, was elected the first rabbi of Brno in 1860. His interest and enthusiasm for science was positive influence on grandson Georg. Rabbi Baruch was a close friend of Johann Gregor Mendel (the father of genetics) and was the first to really understand and appreciate Mendel’s genius. Placzek's brother died eight days after the Nazis' invasion of Czechoslovakia in March 1939 and his parents and his sister died in concentration camps during the Second World War.”

David Eldridge from United Kingdom mentions Placzek’s stay in the Soviet Union:

“The Soviet Union devoted much effort to nuclear research because of the prospect of abundant energy that could be obtained from Uranium. Centered around Kharkov in the Ukraine many leading physicists worked together on nuclear research including George Placzek. One such circle amongst the physicists in Kharkov was known as ‘the Landau circle’ and George Placzek was a part of that circle. Political conflict between individuals within the circle and the Soviet regime and also the events of WWII caused Placzek to join the Manhattan Project as a member of the British Mission. Placzek is thought to have committed suicide in Zurich in 1955 because of illness.”

Gavin Waters writes from Australia:

“The Manhatten project of course was the American secret search for a predicted nuclear chain reaction and in particular Placzek was instrumental in suggesting the way to achieve nuclear fission (with Uranium 235). It is rather interesting that I am living in Australia which has a large resource of Uranium. In today's climatic situation, I feel that nuclear power has a major role to play in our future energy provision.”

Charles Konecny from Ohio takes regular part in our monthly quizzes:

“Placzek was another in a long line of brilliant physicists born and educated in Europe. His insight on the role and use of Uranium 235 in the ‘Manhattan Project’ during WW 2 played a key part in the development of the atomic bomb which was the greatest weapons race of all time. I have read the Nazi effort was there but with the war turning against them they were starting to lack resources and motivation. I enjoy the question each month and look forward to the next one.”

Of course, I won’t leave you without one, but first let me announce the names of the four listeners who will be sent small gifts for their correct answers. This time they are Nooreddin Ahmad Hussein from Jordan, John Rutledge from the USA, Jurij Faltenfors from Sweden, and Jaydeep Chakrabarty from India. Congratulations and many thanks to everyone for taking part!

And finally the promised question:

This month we are looking for the name of the great promoter of the alternative medicine practice of hydrotherapy who was born in 1799 in what is today the North Moravian spa town of Jeseník.

We expect your answers at the usual addresses [email protected] or Radio Prague, 12099 Prague. Don’t forget that the deadline for Radio Prague’s annual listeners’ contest is fast approaching. All the details can be found here: Until next week, happy listening.