I have been a bit of a slacker for the past year, but April is here, which means it’s time for another update to my “asymptotically comprehensive” list of April 1 arXiv joke papers!

This year I found 20 new papers, which the biggest addition yet. On one hand, congratulations researchers! On the other hand, that means a lot of work for me to look over them all — and I can’t even slack off because so many of them are really good.

I couldn’t resist starting with the figure on the right, from Scatophobic Dark Matter brought to my attention by Jim Cline. I mean, look at that cute little pile of poo, so innocent and honest. Unfortunately the paper says we’re going to have a hard time finding experimental confirmation: “…no direct detection signals will be observed before the demise of civilization.” And probably also because it’s stinky, although maybe the experimentalists are used to that. (I kid, I kid)

Explanations for dark matter are a perennial topic of speculation, though, and the scatophobic theory has competition this year: a proposal that dark matter might be made of souls. Souls have long been known …