Published: Leipzig, 1905
Today’s selection is a work of such monumentality that there is essentially nothing new to be said about it. Most people are surprised, though, to learn that it’s a mere three pages long.
Albert Einstein was still working as a patent examiner when, in 1905, he experienced his annus mirabilis or “miracle year,” during which he published four history-changing papers in the Annalen der Physik.
This is the last of the four, and the briefest. Although the notation itself is different, it is in this paper that Einstein first expressed what’s come to be regarded as the most important five-character string 
of the 20th century, if not of all time.
In the fourth-from-last paragraph on page 641, you’ll see the sentence, “Gibt ein Körper die Energie L in Form von Strahlung ab, so verkleinert sich seine Masse um L/V2.”
Or to put it another way: E = mc2