Click on the "stack exchange" dropdown menu in the upper left of your screen (meta or main, doesn't matter). If you're not already there, click on the "hot questions" menu item.
Those hot questions get hotter because they're listed there. This reflects an issue in the global dynamics of all Stack Exchange - that users with an established account in one subject can vote on questions in other subjects.
Yes, there is a criteria for it to get listed in the hot questions to begin with, but it's not very good. Once it starts to pick up steam and get referrals from the global network, its popularity is then dictated by relative non-experts.
Many of my most upvoted answers aren't very good. They're subject matter that appeals better to a layman. That's why the 200 cap makes sense. For physics, at least, there's basically no way to hit that limit on a single question with votes from the regular physics users.
161 avid users
2,175 total users
Once the number of votes on a question or answer is in the neighborhood of 10 or so, that number stops giving much relevant information. The traffic from regular users just isn't high enough to push it further, because we can all only vote once.
I'm not sure if I personally agree with it being a limit on user reputation in a day, because if you want to write 50 answers in one day, I don't see anything wrong with that. But the cap approximates the issue I'm talking about sufficiently.