Philosophers often speculate about possible worlds: ways that things could be. Some of them also believe in impossible worlds: ways that things couldn’t be. Are impossible worlds places where strange things happen, or descriptions, or abstract objects, or something else entirely? How can you describe an impossibility without contradicting yourself? Could we imagine worlds where even the laws of logic are different? Josh and Ray imagine the unimaginable with Koji Tanaka from the Australian National University, co-author of The Many Faces of Impossibility.