Great article!<p>My takeaways from it include practical use-cases for Differential Equations (I was never interested in solving the Heat Equation, btw, how boring is heat?), and what a good article/news/post ranking algorithm should do to avoid sock puppet voting and bot-powered voting rings...<p>If I were to suggest a new title for the article, it would be "How to write a better content ranking algorithm, with examples from Differential Calculus", or perhaps, "Learn Differential Calculus with examples from a real-world content ranking algorithm".<p>Anyway, this article has to be in my top-ten all-time favorites on HN.