The Download: watermarking AI text, and freezing eggs

What's happened: A new method could help us to spot AI-generated texts. Watermarking buries hidden patterns in the text that are invisible to the human eye, but lets computers detect that the text probably comes from an AI system or a human. Why it matters: ChatGPT is one of a new breed of large language models that generate fluent text that reads like a human could have written it. These AI models regurgitate facts confidently, but are notorious for spewing falsehoods, which makes it worrying that they're already being adopted for everything from essays to workout plans. To the untrained eye, it is almost impossible to detect whether a passage is written by an AI model or human.