In May, I asked Google’s chatbot, Gemini, to write a birthday letter to my best friend. Within seconds, it spat out the most impressive piece of AI writing I have ever encountered. Instead of reading as soulless, machine-generated text, the letter felt unnervingly like something I might’ve actually written. “You’re probably rolling your eyes,” the letter read, after a sentence that my friend would most definitely have rolled his eyes at. All I had typed into the chatbot was a nine-word prompt co...