Strange is our situation here upon earth. Each of us comes for a short visit, not knowing why, yet sometimes seeming to a divine purpose. From the standpoint of daily life, however, there is one thing we do know: That we are here for the sake of others...for the countless unknown souls with whose fate we are connected by a bond of sympathy. Many times a day, I realize how much my outer and inner life is built upon the labors of people, both living and dead, and how earnestly I must exert myself in order to give in return as much as I have received and am still receiving.

Much later questions were raised whether the measurements had been accurate enough to support Einstein's theory. Their readings included the works of Henri Poincaré Ernst Mach and David Hume which influenced his scientific and philosophical outlook. Quantizing these oscillators each level will have an integer occupation number which will be the number of particles in it.

Later with the British philosopher Bertrand Russell Einstein signed the Russell–Einstein Manifesto which highlighted the danger of nuclear weapons. Einstein was in support of defending the Allied forces but largely denounced using the new discovery of nuclear fission as a weapon. Roosevelt that Germany might be developing an atomic weapon and recommended that the U.