D O C U M E N T 2 4 6 A P R I L 1 9 2 6 2 5 9 Now I must write you about another matter. From Paris I went to Brussels, where the scientific committee of the Institut international de physique Solvay met with the purpose of preparing the next congress of physics, which is supposed to be held in October 1927. The above-mentioned committee, comprised of Mrs. Curie, Langevin, Rich- ardson, W. H. Bragg, Guye (Geneva), Knudsen, Van Aubel (Ghent), and me, is now in session.[5] Only Bragg and Van Aubel were absent. We have proposed to the ad- ministrative council that you be appointed as a committee member as successor to Kamerlingh Onnes.[6] The administrative council immediately did so, and it would now please all of us very much if you would like to occupy this place in the com- mittee. Because I know that much is being demanded of you from every quarter, I add that now it does not involve a great expenditure of time at all. A congress of physics convenes every third year, in which, as a rule, the members of the commit- tee participate and one year before the congress there is a preparatory meeting (of two days), as we just had. If a member cannot attend, that is no great misfortune, either. On the other hand, your cooperation would be of very special value to us, in the first place, because you have such a complete mastery of modern physics, but also for another reason as well. For, we have resolved, and this with the full concurrence of all the present mem- bers as well as of the entire administrative council (made up of Belgians), to invite Germans again next time. We are now hoping that, if you are a member of the com- mittee, this will contribute toward their accepting the invitation. We chose “The theory of quanta and the classical theories of radiation” as the topic for 1927, and we hope to have the following reports or presentations:[7] [Please re- gard the following as confidential for the time being.] 1. W. L. Bragg. New verifications of the classical theory. 2. A. H. Compton. Compton effect and its consequences. 3. C. T. R. Wilson. Observations on photoelectrons and collision electrons, by the condensation method. 4. L. de Broglie. Interferences and light quanta. 5. (Brief note). Kramers. Theory of Slater-Bohr-Kramers and analogous theo- ries. 6. Einstein. New deductions of Planck’s law and applications of statistics to quanta. 7. Heisenberg. Adaptation of the foundations of dynamics to quantum theory.[8] You can see from this list that we have also placed our hopes on you.