Who is Noam Chomsky from The Armies of the Night: History as a Novel and what is their importance?

Linguist, Noam Chomsky, run into each other at Occoquan where Mailer is being detained for the night. Chomsky is a young man but well respected at MIT, where he his considered a genius. The two men engage in stimulating conversation, after which, Chomsky quickly leaves in order to make it back for classes by Monday morning.