'A glorious idea ... about the absorption and emission of radiation'.
Einstein rejoices in a new discovery: 'A glorious idea about the absorption and emission of radiation dawned on me: it will interest you. An astonishingly simple derivation of Planck's formula – I should rather say the derivation. All completely quantic. I am writing the paper right now' (published as 'On the quantum theory of radiation', 1916). Besso's silence on the subject of Einstein's estranged wife, Mileva, makes him hopeful that her condition is improving. He passes on news of a friend whose family have been displaced by the conflict on the Austrian-Italian front, mentions a planned trip to Holland, asks Besso about his lecturing in Zurich, and urges him (optimistically) to visit Berlin 'when peace comes'.