The caustic mathematician Roger Casals Gutiérrez saw on his kitchen wall in 2023. Caustics are a type of singularity, a mathematical phenomenon that occurs when an surface goes through a transition.

Can we do away with the troublesome singularity at the heart of black holes? A new paper in JCAP reimagines these extreme objects in light of current knowledge. “Hic sunt leones,” remarks Stefano ...

Imagine the tap of a card that bought you a cup of coffee this morning also let a hacker halfway across the world access your bank account and buy themselves whatever they liked. Now imagine it wasn’t ...