But this?
the duplicate posts which happen a few months later
Once we're up to a timescale of months, or even weeks, we're no longer being sensible. Instead we're exhibiting FAQ Syndrome: The irrational fear that someone, somewhere, is saying something that isn't entirely original.
I think the cult of originality is actually a big problem at HN, and other "news" sites as well. The important things in life are not particularly original, and they do not change particularly quickly. A site that is determined not to re-discuss previous topics is doomed to discuss nothing but ephemeral trivia. The great thing about celebrity gossip is that it is always new! We can manufacture celebrities at whatever rate is needed to keep the front page fresh. But we can't manufacture Knuths as needed; we've only got the one set of Maxwell's equations; new books on the scale of K&R or SICP don't come along every day. But if we discourage the constant reexamination of these classics they will get placed on the dusty shelves and we'll see nothing but discussions of the latest gossip and bling. You know, like we have today.
I always wished HN would feel more like academia, which cycles like the seasons. Every year, you discuss all the classics again for a new audience of newbs. After a little while, you've heard all the classics and are ready to graduate, or become a professor. This is what makes me miss the days when this was "Startup News" and was more explicitly tied to the YC cycle, the time when you could tell that a new YC class was starting by watching for the influx of new people.
Perhaps there should be a "hard merge" that prevents duplicates from sharing the front page, and a "soft merge" that multiplexes comments from duplicates at any time range under any of the submissions?
I wish there were places to go online to teach or be taught about topics in a discussion-forum kind of way. I'd love, for example, a Lambda the Ultimate for newbs. LtU is an awesome, high-quality site, I just wish I could understand more than 10% of it.
I tend to use HN when I'm too tired to work or just waking up. Those are also the times when I'm not interested in buckling down and studying a hard subject. But surely I could do better than the kind of learning I get from HN (and other casual internet use), which is random access to shallow, scattered tidbits, as if training for a massive Trivial Pursuit tournament you never signed up for. If only there were a community where people devoted themselves to teaching and learning classic topics in a sustained way, but that still had the social and casual aspect. News as such doesn't interest me that much. I'm mostly just consuming it by default. If anyone's read this far - my apologies for adding a mostly off-topic comment to an already crowded thread.