Solvay Conferences in physics

Jagdish Mehra, The Solvay Conference in Physics Aspects of the Development of Physics since 1911 (Dordrecht Reidel, 1975) xv. 

The number of Solvay Conferences in Physics, held in Brussels every few years, starting from 1911 until 1982, has been 17. 

The first Solvay Conference in Physics, however, set the style for a new type of scientific meeting as Mr. Jacques Solvay told us, the participants in the meeting formed a select group of the most informed experts in a given field which met to discuss one or a few related problems of fundamental importance and seek to define the steps for their solution. 

The proceedings of the old Solvay Conferences in Physics forever will remain sources of information of a unique kind about the historical development of our present views. It is much more difficult, perhaps impossible, to make a similar statement about the more recent Solvay Conferences. Only in 10 or 20 years from now will they be seen in the right perspective. What we know with certainty, from now, is that the 17 Solvay Conferences in Physics provide in their ensemble a succession of pictures of the state of our knowledge of the physical world as it was changing at intervals of a few years, all taken with the same camera from essentially the same point of view. ... 

The participants in the 1st Solvay Conference in Physics are shown in Fig. 1, which reproduces the, perhaps, most famous photograph of physicists of any time. 

Fig. I. Photograph of the participants in the First Solvay Conference in Physics (1911).

The 3rd Solvay Conference in Physics took place in 1921, after a long interruption due to the First World War. Its theme was Atoms and Electrons. 20 It was centered on the Rutherford model of the atom and Niels Bohr s atomic theory. Bohr, however, was not able to attend the conference because of illness. 

The 7th Solvay Conference in Physics was held in 1933, and was entitled the Structure and Properties of Atomic Nuclei. 41 It was chaired by Langevin who, after the death of Lorentz (4 February 1928), had become President of the Scientific Committee. It took place at a time when the field had recently undergone extremely rapid developments. The conference was really marking the beginning of modern nuclear physics. 

The next Solvay Conference in Physics, the 8th from the beginning, took place in October 1948, that is, 15 years since the previous one. The Scientific Committee was now chaired by Sir Lawrence Bragg. The general theme of the conference was Elementary Particles. 55... 

I come now to the last group of Solvay Conferences the three regarding astrophysical problems. The first one, devoted to The Structure and Evolution of the Universe was held in June 1958. It was the 11th Solvay Conference in Physics.101... 

The 16th Solvay Conference in Physics, held in September 1973, was entitled Astrophysics and Gravitation. 110 The progress undergone in many fundamental chapters of astrophysics with respect to the previous conference, held in 1964, was really striking. In particular, X-ray astronomy had won a status comparable with other conventional branches of astronomy. 

I am now at the end of my series of flashes on the Solvay Conferences in Physics. I hope that, in spite of its shortness and incompleteness, it may help in stimulating two kinds of considerations. Those of the first kind regard the extraordinary develoment undergone during the last 70 years by our views on the physical world, many parts of which in present days appear to be dominated by a few general concepts, such as those of exact and approximate symmetry, and to be treatable by mathematical procedures such as the application of the renormalization group. The other kind of considerations concerns the role that the Solvay Conferences in Physics have played in the development of physics during the last 70 years, and the unique value they will maintain, even in the future, as sources of information for the historians of science. 

These remarks can be found in the few pages of introduction to the album of photographs of the participants in the Solvay Conferences in Physics, published in 1961, on occasion of the celebration of 50 years after the First Solvay Conference. These pages are based on the unpublished paper Jean Pelseneer, Historique des Instituts Intemationaux de Physique et de Chimie Solvay, depuis leur fondation jusqu it la deuxilme guerre modiale, Bruxelles, 1946. 

Astrophysics and Gravitation, Proceedings of the Sixteenth Solvay Conference in Physics at the University of Brussels, 24-28 September 1973, Editions de PUniversitd de Bruxelles, Brussels, 1974. 

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