We now coexist with machines so vast and so complicated that nobody quite understands what they are, how they work, or what they can really do—not even the people who help build them. “You can never really fully grasp it in a human brain,” says Dan Mossing, a research scientist at OpenAI. That’s a problem. Even though nobody fully understands how it works—and thus exactly what its limitations might be—hundreds of millions of people now use this technology every day. If nobody knows how or why mo...