Ambiguity and its cousins, contradiction and paradox, are everywhere in mathematics, both in content and thinking. Strangely, the subject that appears to be the very paradigm of reason, and that is ...

Time travel is deterministic and locally free, a paper says—resolving an age-old paradox. This follows research observing that the present is not changed by a time-traveling qubit. It’s still not very ...

Have you played the puzzle game Tangram? I remember, as a child, being fascinated by how just seven simple wooden triangles and other shapes could offer endless entertainment. Unlike LEGO, the Tangram ...