D O C . 1 2 0 O N S C H O L A R S D E C E M B E R 1 9 2 5 1 4 1 tion with the general electromagnetic field theory and with relativity theory on the other hand, however, that the results of quantum mechanics do not necessarily have to lead to the last-described difficulties at all among the various possibilities, for instance, the simple assumption would be conceivable that a consistent application of the theory in connection with relativity theory would produce the result that the energy of a pure translation would not be but would differ from it by terms of the order of magnitude of h, in accordance with the matrix interpretation of p or more simply put, that the energy of the oscillator would be , which obviously cannot change the results for a solid body, either, provided the above form is correct. But these latter possibilities are initial guesses out of the blue, and in reality I haven’t a clue how this connection will later take shape. When I wrote about geometry in the last letter, I actually always meant kinemat- ics (which one can, of course, in a certain sense also call geometry).[7] That a mod- ification of present-day kinematics is necessary, however, already follows from the fact that the lines of a series are not (as classically assumed) equidistant but rather converge toward a finite limit. You are probably right that our formulation of quantum mechanics is more adapted to the Bohr-Kramers-Slater view [8] but that is just one side of the coin concerning radiation phenomena, of course. The other side is your theory of light quanta and we do have the hope that someday the validity of the conservation law of energy and momentum in our quantum mechanics will make a link to your the- ory possible. Please pardon us this time, too, for plaguing you too long with unfinished thoughts and theories and thank you very much again for your letter. Yours sincerely, Werner Heisenberg 120. Aphorism on Scholars [Berlin, December 1925][1] Scholars could have achieved something of value as the avant-garde of peace they will hardly be needed as a reserve army.[2] A. Einstein m0v2 1 2m ------- p2 + E 1 2m -------( p2 ω2q2) + hν 2 ----- -– = E 1 2m -------p2 a q5 ---- - b q2 ---- - – const + + =