It’s not every day that a well-known author writes a physics paper. But George R R Martin, who is best known for his Song of Ice and Fire series of fantasy novels, has co-authored a paper in the American Journal of Physics with the title “Ergodic Lagrangian dynamics in a superhero universe”.

Martin and “Wild Cards” author Ian Tregellis turn a scenario from the sci-fi series into the entertaining foundation for an exercise in open-ended problem solving.