Author and authority have the same root word. It’s a small point but thought the etymology was interesting.

• 1230, “Authority” — autorite “book or quotation that settles an argument,” from O.Fr. auctorite, from L. auctoritatem (nom. auctoritas) “invention, advice, opinion, influence, command,” from auctor “author” (see author).
• c.1300, “Author” — autor “father,” from O.Fr. auctor, from L. auctorem (nom. auctor) “enlarger, founder,” lit. “one who causes to grow,” agent noun from augere “to increase” (see augment).
• c.1380. “Author” — “one who sets forth written statements”
• 1393 Authority — “power to enforce obedience”
• 1596. “Author” — as verb
• 1611: “Authority” —”people in authority”
• Authoritative first recorded 1609.
• Authoritarian is recorded from 1879.
• 2005: “Author” — “man or woman who adds to opinions or knowledge to the web” from O.Fr. auctor, from L. auctorem (nom. auctor) “enlarger, founder,” lit. “one who causes to grow,” agent noun from augere “to increase” (see augment).
• 2010: “Authority” — as collective noun for authors in the same fields or contributing to the same project cf. “the authority of Wikipedia”

OK. I added a couple.