Focus on boosting comments instead of sheer volume of posts—people post specifically because they want answers, and seeing a long stream of posts with no responses makes them think it’s not worth bothering.
I think people’s familiarity with the r/askhistorians subreddit may be discouraging anyone without graduate-level academic experience from responding, but the subreddit didn’t start out requiring that level of rigor—it became more selective as the volume of replies increased. But for here, even a general-knowledge reply can encourage clarifying comments from more-informed people who may otherwise doubt their qualifications.
I think you’d immediately collapse into a wadded-up ball of super-dense matter.
The Pauli exclusion principle keeps particles like electrons from occupying the same physical space, which is what makes them take up volume and gives atoms and molecules their size. If they were free to move in an extra spatial dimension, they could pack much closer together, and their volume would collapse.