Those two are established authors. If this is your first novel, needing a separate glossary or apendix for your novel may hurt your chances of getting it published. I'm not saying it is impossible though. It might just make things more difficult. If the reader can easily figure out what a piece of technology is for on their own, or can easily relate to the situation the MC is in, that is as good or better than explaining. I just suggest against doing like Star Trek where they throw in meaningless technobable as filler.
I didn't realize it was going to be a novel when I started the first line. That's true, once I put effort into building a milieu, why stop at one story?
Dragon's Egg was Forward's first novel. He said it is "a textbook on neutron star physics disguised as a novel." The first novel by Hal Clement, Needle, doesn't have an appendix. Mission of Gravity is his 3rd, it seems. I'm not saying that it needs an appendix. It's just interesting to some to read more about the world of the story. Are you familiar with what I referred to as "hard" SF? It doesn't have meaningless technobabble. The science and technology is quite real, or made-up stuff is at least used in a fully logical and consistent manner just like the real stuff.
