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What's Missing Between LLMs and AGI - Vishal Misra & Martin Casado

47 min episode · 2 min read
·
Vishal Misra,Martin Casado

Episode

47 min

Read time

2 min

Topics

Startups, Fundraising & VC, Artificial Intelligence

AI-Generated Summary

Key Takeaways

  • Bayesian Wind Tunnel methodology: To prove LLMs perform true Bayesian inference rather than superficial pattern matching, Misra's team created controlled experiments using blank architectures trained on tasks mathematically impossible to memorize. Transformers matched the analytically calculated Bayesian posterior to 10⁻³ bit accuracy. Mamba performed nearly as well; LSTMs partially; MLPs failed entirely. Architecture, not training data, determines this capability.
  • The Frozen Weights Problem: LLMs perform Bayesian updating within a conversation but reset completely when a new session begins — weights are frozen post-training. Human brains maintain synaptic plasticity throughout life, continuously updating from experience. Continual learning research must solve catastrophic forgetting: updating weights on new information without erasing previously learned knowledge before plasticity becomes viable.
  • Shannon Entropy vs. Kolmogorov Complexity: LLMs operate in the Shannon entropy domain — learning correlations across all available data. Human reasoning operates closer to Kolmogorov complexity — finding the shortest causal program that explains observations. Einstein's field equation (Gμν = 8πTμν) is a minimal representation explaining Mercury's orbit, gravitational lensing, and GPS simultaneously. LLMs cannot generate equivalent new representations.
  • The Einstein AGI Test: A concrete benchmark for AGI: train an LLM exclusively on pre-1911 physics data and determine whether it independently derives the theory of relativity. Current models would fail because they are bound to existing data manifolds and cannot construct new causal representations that reconcile anomalous observations like Michelson-Morley experiment results with Newtonian mechanics.
  • Causation vs. Correlation as the Core Gap: Deep learning performs association — the first tier of Judea Pearl's causal hierarchy. It does not perform intervention or counterfactual reasoning, which require internal simulation models. When a person dodges a thrown object, the brain runs a causal simulation, not a probability calculation. Building architectures capable of causal modeling, not scaling existing ones, is the necessary research direction.

What It Covers

Columbia University professor Vishal Misra presents mathematical proof that transformers perform precise Bayesian inference, matching theoretically correct posteriors to 10⁻³ bit accuracy. He argues two unsolved problems — continual learning plasticity and moving from correlation to causation — separate current LLMs from genuine artificial general intelligence.

Key Questions Answered

  • Bayesian Wind Tunnel methodology: To prove LLMs perform true Bayesian inference rather than superficial pattern matching, Misra's team created controlled experiments using blank architectures trained on tasks mathematically impossible to memorize. Transformers matched the analytically calculated Bayesian posterior to 10⁻³ bit accuracy. Mamba performed nearly as well; LSTMs partially; MLPs failed entirely. Architecture, not training data, determines this capability.
  • The Frozen Weights Problem: LLMs perform Bayesian updating within a conversation but reset completely when a new session begins — weights are frozen post-training. Human brains maintain synaptic plasticity throughout life, continuously updating from experience. Continual learning research must solve catastrophic forgetting: updating weights on new information without erasing previously learned knowledge before plasticity becomes viable.
  • Shannon Entropy vs. Kolmogorov Complexity: LLMs operate in the Shannon entropy domain — learning correlations across all available data. Human reasoning operates closer to Kolmogorov complexity — finding the shortest causal program that explains observations. Einstein's field equation (Gμν = 8πTμν) is a minimal representation explaining Mercury's orbit, gravitational lensing, and GPS simultaneously. LLMs cannot generate equivalent new representations.
  • The Einstein AGI Test: A concrete benchmark for AGI: train an LLM exclusively on pre-1911 physics data and determine whether it independently derives the theory of relativity. Current models would fail because they are bound to existing data manifolds and cannot construct new causal representations that reconcile anomalous observations like Michelson-Morley experiment results with Newtonian mechanics.
  • Causation vs. Correlation as the Core Gap: Deep learning performs association — the first tier of Judea Pearl's causal hierarchy. It does not perform intervention or counterfactual reasoning, which require internal simulation models. When a person dodges a thrown object, the brain runs a causal simulation, not a probability calculation. Building architectures capable of causal modeling, not scaling existing ones, is the necessary research direction.

Notable Moment

Misra describes Donald Knuth's viral Hamiltonian cycle result as validation of LLM limits rather than evidence of emerging generality — the models exhausted their search space and stalled, while Knuth himself constructed the novel mathematical proof, demonstrating that humans still supply the causal reasoning layer.

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Episode Transcript

Adprobic makes great products. PlotCore is fantastic. Co worker is fantastic. But they are cranes of silicon doing matrix multiplication. They don't have consciousness. They don't have an inner monologue. You take an alum and train it on pre 19 '16 or 1911 physics and see if it can come up with the theory of relativity. If it does, then we have ASIA. Just today, by the way, Dario allegedly said that you can't rule out that they're conscious. You can rule out their Awesome. I think. Unconscious to get to what is called easy eye. I think there are two things that need to happen. Five years ago, Vishal Misra got GPT three to translate natural language into a domain specific language it had never seen before. It worked. He had no idea why. So he set out to build a mathematical model of how LLMs actually function. The result? A series of papers showing that transformers update their predictions in a precise, mathematically predictable way. In controlled experiments, the models match the theoretically correct answer almost perfectly. But pattern matching is not intelligence. LLMs learn correlation. They don't build models of cause and effect. To get to AGI, MISRA argues, we need the ability to keep learning after training and the move from correlation to causation. Martin Casado speaks with Vishal Misra, professor and vice dean of computing and AI at Columbia University. Michelle, it's great to have you in again. Great to be back. This is one of my favorite topics, which is how do LLMs actually work. Mhmm. And I think that and in my opinion, you've done kind of the best work on this modeling it out. Thank you. For those that did not see the original one, maybe it's probably worth doing just a quick background on kind of what led you to this point, and then we'll just go into the current work that you've been doing. Five years ago, when GPT three was first released Oh. I got early access to it. And I started playing with it. And I was trying to solve a problem related to querying a cricket database. Yeah. And I got g p d three to do in context learning, few short learning, and it was kind of the first, at least, to to me, it was the first known implementation of RAG, retrieval augmented generation, which I used to solve this problem of querying, getting GPT three to translate natural language into something that could be used to query a database that GPD three had no idea about. I had no access to GPD three's internal, but I was still able to use it to solve that problem. So it worked beautifully. We deployed that as in production at ESPN in September 21. But Wow. You did the first implementation of Frac in 2021? No. No. No. In 2020. 2020. 2020, I got it working. And by the time you talk to all the lawyers at …

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  • by Judea Pearl

    Deep learning performs association — the first tier of Judea Pearl's causal hierarchy. It does not perform intervention or counterfactual reasoning, which require internal simulation models.

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