I feel horrible right now (please read, very brief)...?

Good for you for being interested in science! I think you're fine. The way I see it, everyone deserves answers. If he chooses not to answer you, that's his loss at enlightening another young mind, which is a huge part of science! I think your best is to finish the book, do a little research on your own to try to learn about his position (sounds like you've started) and try again. These questions cn also be addressed here, maybe a little more help will give you specific questions to ask next time. It's a good idea to have your dad or someone else proof read your letter, just to make it seem a little more valid.