To Jerry Friedman: For some odd reason it didn't occured to me to google Atomic Age, but that seems to be the clue!
On the other hand, VN always tried to enrich those cliches he employed, and in this case, likewise, he might have been fascinated by the fact that Anno Atomus and Atomic Age are both AA in short, which also, funnily enough, coincided with the year he got a permanent citizenship in America / Arcadia (ha-ha). This might have looked like a perfect pun for him.
-----
People in the know correted my 'little Latin'. Below I'm copying the correction with commentary, courtesy of Sergey Karpukhin:
In "Anno Domini," "anno" is ablative singular of a noun (annus, "year"), and "domini" is genitive singular of a noun (dominus, "Lord"). In "Anno Americano," however, "Americano" is an adjective (ablative, singular, masculine, in agreement with "anno"). So the translation would be: "in the 200th American Year." "200th Year of America" sounds odd to me, that's why I used an adjective.
But "Anno Atomi" works exactly like "Anno Domini": instead of the "in year of our Lord" we have the "in year of (the) Atom."
So the right way to put it would be: Anno Americano and Anno Atomi.
Andrey
On Fri, 24 Jun 2011 12:43:30 -0600, Jerry Friedman <jerryfriedman1@GMAIL.COM> wrote:
>I feel certain that Andrey Vakhrulin is right to connect 1945 with "Anno
>Atomus" (taking his word on the Latin), or just as likely, "Atomic Age". As
>a search of Google Books will show, the latter phrase immediately became a
>cliche. An example in a date is "On the calendar, this is the year 1947.
>But it is also the year 2-AA, the second year of the atomic age."
>
>Robert Ducharme Potter, *Young People's Book of Atomic Energy* (1946), p.
>44.
>
http://books.google.com/books?id=2NfqAAAAMAAJ&q=%22second+year+of+the+atomic+age%22&dq=%22second+year+of+the+atomic+age%22&hl=en&ei=DtgETo6aL8LegQfzlsG_DQ&sa=X&oi=book_result&ct=result&resnum=1&sqi=2&ved=0CC0Q6AEwAA>
>For what my guess is worth, the ingenious connection to VN's American
>citizenship might have been a private, secondary meaning.
>
>Jerry Friedman
>