Now that John99 has blocked me I figure I can post my guesses about what he's doing here. I think it comes down to three possibilities: 1) He really doesn't understand any of this. This is perhaps the most charitable interpretation of his antics; he really doesn't have the mental capacity to understand, for example, the implications of the speed of light, or how someone's eye responds to light. It's been explained to him about every way possible, so if he's not getting it now he may be incapable of that level of understanding. If that's the case I actually feel a little bad for the guy. It can't be fun to participate in discussions where you are always going to be a step behind. But I think that's unlikely, since few people are that limited, and typically they write even more poorly than John99. 2) He is actively trying to misunderstand this. People on the Internet do that a lot. Often it's more direct than what John99 is doing - usually it's more of a "I'm against abortion" "oh, so you therefore want women to die" sort of thing. John, however, is just saying over and over "I don't get it, here's another unrelated tangent, here's another theory I suspect is wrong that should really derail the discussion." It may be that he just wants attention, pity and/or sympathy and this is the easiest way for him to get it. If he is doing this, then he is a master of intentional misunderstanding; at this point it would take a lot more effort to intentionally misunderstand the subject than it would to understand it. 3) He understands it just fine and is just plain trolling to get people worked up. This is probably the most likely scenario, since few people are really that limited intellectually (and he seems pretty high functioning for someone that limited.) Since he is still responding to people even after he blocked their posts this seems more likely; he is hoping to elicit a response by doing the Internet equivalent of sticking his fingers in his ears and saying "I'm not listening! I can't hear you! Naaaa naaaa!" In addition, his attitude that getting someone to look at your posts is a good thing would tend to support the theory that the guy is a troll. Trolls want to be seen. A while back I stood up for the guy. It seemed like a lot of people were going after him just because he wasn't getting the material. But after 500 posts it's become pretty clear that this isn't just a case of someone taking a long time to understand a simple subject; there's something else going on. So now I can better understand where James R is coming from with all the bans.