memes The ultimate trolley problem crams in every other philosophical question it can Thom Dunn

Sex Can time travelers go back in time and have sex with themselves? Astrophysicists investigate. Thom Dunn

time Here are all the ways time is an illusion Andrea James

paradoxes The paradox of The Bottle Imp Mark Frauenfelder

paradoxes The absent-minded driver's paradox Mark Frauenfelder

paradoxes 20 amusing paradoxes and dilemmas to ponder Mark Frauenfelder

paradoxes Unanimous decisions are less reliable Mark Frauenfelder

puzzles The Missing Dollar puzzle from Martin Gardner's Aha! Gotcha book series Mark Frauenfelder

Funny Four sets of identical twins pull an epic NYC subway car time-machine prank Cory Doctorow

HDSF Have you committed a Time Crime? Maybe you will… Jesse Sheidlower

game theory How "God Makes God" is a 1993 CD-ROM about probability, game theory, genetic algorithms, and evolutionary strategies Mark Frauenfelder

mathematics New research: There's a 50-50 chance we're living in a simulation and here's how to find out David Pescovitz

books Paper Girls 5: fate and free will (and dinosaurs and monsters) Cory Doctorow

late stage capitalism The paradox of good government: the best stuff works well and is thus unnoticeable (and therefore easy to sell off) Cory Doctorow

happy mutants Brain-aching list of counterintuitive probability riddles Cory Doctorow

optical illusions Impossible objects, explained David Pescovitz

optical illusions The Playful Eye is a virtual feast of games and visual tricks gathered from around the world Kevin Kelly

picks Star Wars icon Carrie Fisher dead at 60 Xeni Jardin