Is there a way to decipher Prof. Goopton's language using in-game cues
Are there hints in the game to decrypt his characters to our alphabet?
I.e. by our own observation and without (Spoiler):
Without using the Sponge
Solution 1:
No, there are no in-game cues to help translate what he says. (Except the item you mentioned)
If you want to translate it yourself:
He speaks Alienese, a language from futurama