D O C U M E N T 1 0 2 N O V E M B E R 1 9 2 5 1 8 3 [1]Einstein 1924o (Vol. 14, Doc. 283). [2]See Einstein to Erwin Schrödinger, 28 February 1925 (Vol. 14, Doc. 446). [3]Bose 1924a (Vol. 14, Doc. 278). [4]Jeans 1905 and Debye 1910. [5]Doc. 80. [6]In Planck 1925a Max Planck had first quantized the energy of a gas as a whole and had then proceeded to quantize the energy of the individual constituent molecules. Both Planck himself and Schrödinger (see Schrödinger 1925b) had pointed out that this was problematic because it was unclear how one should quantize the translational motion of molecules it is presumably this difficulty that Schrödinger is referring to here. [7]Alfred Landé. Landé 1925. [8]Presumably a reference to the results of Einstein’s quantum theory of the ideal gas and its pre- diction of condensation in the lowest energy state (see Einstein 1925f [Vol. 14, Doc. 385]). [9]Broglie 1924. [10]Sec. 8 of Einstein 1925f (Vol. 14, Doc. 385). [11]See Schrödinger 1922. The curious property is that for each (quasi-)periodic trajectory the exponent is an integral multiple of , with γ a constant with the dimension of an action. See Doc. 473 for discussion of this insight by Weyl himself and O’Raifeartaigh 1997, pp. 77–78 for a dis- cussion of Schrödinger’s contribution to the origins of gauge theory. 102. From James H. Jeans[1] London, 5th November, 1925. My dear Einstein, It gives me great pleasure to send you the enclosed letter.[2] The Copley Medal, as you probably know, is the highest honour which the Royal Society has it in its power to award, and I think you are the youngest recipient in the two hundred years or so since it has been awarded [3] in any case if you are not, I think you ought to be. Many of us would be very glad if you could find time to come yourself in person to receive the Medal the formalities are only slight and do not involve making any speeches. In the hope that you can come I am enclosing an official invitation, in- viting you to attend as a guest of the Royal Society at their Anniversary Dinner. I very much hope we shall meet there. Yours sincerely, J. H. Jeans TLS. [30 206]. The letter is addressed “Prof. Albert Einstein, For. Mem. R. S.” on letterhead of the Royal Society. [1]Jeans (1877–1946) was a British physicist, astronomer, and mathematician, honorary secretary of the Royal Society, and president of the Royal Astronomical Society. [2]see Abs. 178. [3]The Copley Medal is named for its initial benefactor, Sir Godfrey Copley (1653–1709) and had been awarded annually since 1731 “for outstanding achievements in research in any branch of sci- ence” (see Yearbook 1995, p. D-38). The medal [65 078] was presented (in Einstein’s absence) at the anniversary meeting of the society on 30 November 1925 by the retiring president, Sir Charles Sher- rington. For the citation made with the award of the medal at the meeting, see Science 1926. γ 1– h