[jlcx]

Thanks for the compliment! The larger graph is basically built by extracting all relationships of certain types (e.g. parent/child, teacher/student, cause/effect) from Wikidata, along with the earliest known date for the items (e.g. date of birth, time of invention/discovery). The layout started as a 3D force-directed layout, but I turned one axis into the timeline. For the visualization, I used (forked) https://github.com/anvaka/pm (which did get some deserved attention here: https://news.ycombinator.com/item?id=40817852 ) and the related ngraph.offline.layout repo.

Trying to answer your final question: there are a lot of things that I should probably improve here, but I've also wondered if this kind of giant graph visualization just doesn't really work for most people.