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

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

subjectivity 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

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

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