I have been thinking it would interesting to do the following experiment. Pick two random new posts and show them directly on the home page for a fixed amount of time. Feed the data from those posts (views, votes, content, comments) into some neural network which can magically learn what kind of posts generate most interest.

Showing random, new posts on the home page provides equal viewership to the experiment set while removing the age bias. Many candidate posts will likely be low quality, but we can expect people to filter them out and participate less in them. High quality posts will organically attract people's attention and the algorithm can over time learn factors that differ between lower quality and higher quality posts.