World Models

🎧 Prefer to listen? Your browser does not support the audio element. Two weeks ago, Anthropic published a paper that should change how you think about your AI tools — and almost nobody outside of research circles understood what it actually said. We covered Claude’s “inner life” and OpenAI’s super app when the news broke, and before that, how Sonnet 5 made agents affordable for solo builders. But the J-Space discovery and the rise of world models deserve a deeper look — because the implications go far beyond academic curiosity. ...

🎧 Prefer to listen? Your browser does not support the audio element. Anthropic’s interpretability team used a technique called the “Jacobian lens” to identify a zone inside Claude’s neural network where abstract concepts — things like “the user wants a comparison” or “this fact needs verification” — float around during processing. These concepts shape Claude’s answer but never appear in the output. A 2025 MIT Technology Review interview with senior editor Will Douglas Heaven, who holds a PhD in computer science, pushed back on Anthropic’s framing of this discovery: “I don’t love using those kinds of terms. LLMs are not brains.” ...