How to keep AI sweet: ask it about marmalade | Brief letters

Global conservation | An early lunch | Cat’s dinner | Customer feedback | The Lord’s nameGuardian readers have known for some time how to stop AI systems from taking over the world (Robots say they have no plans to steal jobs or rebel against humans, 8 July). Simply keep them busy answering two questions: “When is the best time to make orange marmalade?” and “How many uses can you think of for a 35mm film canister?”
Jonathan Gregory
Stockholm, Sweden• For