Nowadays, the letter Η/η is called "ita" by Greeks and "eta" by physicists. But I'm curious: if I went back in time and talked to Socrates, what name would he have used?
Background: historically, Η came from the Phoenician letter het (or heth), which represented a
/ħ/ sound. Some Greek dialects used it as a consonant, which is how we get the English letter "H", while others used it as a vowel, which is how we get the Greek letter "Η". (EDIT: As Alex B points out, some used it for both a consonant and a vowel, like how Latin used "V".)
The name clearly comes from het, and in the consonant-using dialects it would make perfect sense to call the letter heta. I've also come across this quote from a scholium on Dionysius Thrax:
Διὰ τί τὸ "η" πρὸ τοῦ "τ" ψιλοῦται, ἐν δὲ τῷ ἧτα τῷ ὀνόματι τοῦ στοιχείου δασύνεται; Ἐπειδὴ παρὰ τοῖς ἀρχαίοις ὁ τύπος τοῦ "Η" ἐν τύπῳ δασείας ἔκειτο, ὥσπερ καὶ νῦν τοῖς Ῥωμαίοις.
Why is Ē before T pronounced without an
/h/, when the name of the letter "hēta" is pronounced with one? It's because the ancients used the letter hēta for the
/h/consonant—like the Romans still do nowadays. (Trans. mine, and somewhat loose)
However, I've never actually heard someone call the letter "heta", and it seems I'm not alone in this. I have heard people call Υ/υ hypsilon, so it's probably not just
P.S. I'm most interested in what the post-Eucleidian Attics called it, since they still had an
/h/ phoneme, but used the letter Η as a vowel. Answers from other dialects would also be interesting, but Attic is most relevant here.