Meta's LeCun Warns LLM Scaling Will Not Yield Human-Level AI

Why Can't AI Make Its Own Discoveries? — With Yann LeCun — Alex Kantrowitz

Alex Kantrowitz

Language models cannot make scientific discoveries or reason because discrete token prediction lacks an internal world model, requiring AI development to shift toward sensory-trained architectures.

AI-assisted summary of Why Can't AI Make Its Own Discoveries? — With Yann LeCun — original source. Check the original for full context.

Source published:

Key ideas

  • Yann LeCun argues that LLMs will never achieve human-level intelligence or make original scientific discoveries because they lack internal world models, operate solely on discrete token retrieval, and face severe diminishing returns after exhausting natural public text. (0:00)
  • True intelligence requires four foundational pillars absent in current language models: understanding the physical world, persistent memory, reasoning beyond token-space generation, and the ability to plan action sequences toward goals. (29:37)
  • Pixel-level video generation models like Sora cannot serve as real world models due to the mathematical intractability of predicting high-dimensional continuous distributions, necessitating non-generative architectures like Joint Embedding Predictive Architecture (JEPA). (40:44)
  • Enterprise generative AI adoption faces a severe last-mile reliability barrier, with only 10% to 20% of proof-of-concept projects advancing to production due to a persistent 5% hallucination rate and high inference costs. (21:13)
  • Open-source research fundamentally outpaces closed labs by recruiting global talent and decentralizing innovation, exemplified by foundational breakthroughs like ResNet originating in Beijing and the initial LLaMA model being developed by a 12-person team in Paris. (54:33)

Detailed notes

## Background This episode of the Big Technology Podcast, hosted by Alex Kantrowitz, was published on YouTube on March 19, 2025. It features Meta's Chief AI Scientist Yann LeCun in an in-depth conversation exploring why generative AI models struggle to make original scientific discoveries despite ingesting the world's text. According to the show description, the discussion covers the limits of large language models, the need for abstract world models and non-generative architectures like JEPA, the risks of investor disappointment, and the strategic importance of open-source AI after DeepSeek.

## TL;DR Yann LeCun argues that large language models are fundamentally incapable of making authentic scientific discoveries or achieving human-level intelligence because they operate strictly on statistical token prediction rather than internal mental models of the physical world. While industry scaling of autoregressive text and pixel generation faces diminishing returns and fails to solve basic logic or planning, a four-year-old child acquires vast intuitive physics through rich perceptual data with far less computational overhead. LeCun advocates for non-generative architectures like the Joint Embedding Predictive Architecture (JEPA) that predict actions in abstract latent space to enable genuine reasoning, verification, and goal-directed planning. Finally, he stresses that progress cannot be bottlenecked within secretive proprietary labs, defending globally distributed, open-source scientific collaboration as essential for long-term technological advancement.

## Atmosphere & style The conversation carries an intellectually grounding, collegial, and refreshingly pragmatic tone that cuts sharply through prevailing Silicon Valley hype. As long-time interlocutors with a decade of rapport, Kantrowitz plays the engaged, probing surrogate for public and market anxieties, while LeCun delivers candid, authoritative, and occasionally sardonic dismissals of overfunded AI claims. Listening to the dialogue feels like sitting in an advanced computer science seminar where theoretical rigor meets historical perspective, moving briskly from foundational neuroscience and classical AI dilemmas to quantitative data comparisons. The emotional arc transitions from an unsparing deconstruction of current LLM limitations into an energizing, scientifically optimistic defense of open research and abstract world models.

## Bulletin - [00:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=0s) Yann LeCun argues that LLMs will never achieve human-level intelligence or make original scientific discoveries because they lack internal world models, operate solely on discrete token retrieval, and face severe diminishing returns after exhausting natural public text. - [29:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1777s) True intelligence requires four foundational pillars absent in current language models: understanding the physical world, persistent memory, reasoning beyond token-space generation, and the ability to plan action sequences toward goals. - [40:44](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2444s) Pixel-level video generation models like Sora cannot serve as real world models due to the mathematical intractability of predicting high-dimensional continuous distributions, necessitating non-generative architectures like Joint Embedding Predictive Architecture (JEPA). - [21:13](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1273s) Enterprise generative AI adoption faces a severe last-mile reliability barrier, with only 10% to 20% of proof-of-concept projects advancing to production due to a persistent 5% hallucination rate and high inference costs. - [54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) Open-source research fundamentally outpaces closed labs by recruiting global talent and decentralizing innovation, exemplified by foundational breakthroughs like ResNet originating in Beijing and the initial LLaMA model being developed by a 12-person team in Paris.

## Key takeaways - [00:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=0s) Society has conflated artificial intelligence with LLMs, which are merely statistical token retrieval systems incapable of formulating new questions or inventing novel scientific concepts. - [01:55](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=115s) Human thought does not occur in language; biological language centers like Broca's area function as modular output layers for underlying mental representations and world simulations. - [05:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=340s) Techniques like Chain of Thought merely bolt superficial patches onto autoregressive models rather than performing genuine reasoning through structured solution spaces. - [10:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=640s) LLM scaling faces diminishing returns as public internet text (10¹³ to 10¹⁴ tokens) is exhausted, driving up data generation costs while failing to fix basic logical deficits. - [13:30](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=810s) Current systems lack Kahneman's System 2 deliberate planning, preventing them from solving novel, zero-shot real-world problems the way humans and animals naturally do. - [16:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=989s) Massive capital expenditure into current LLM architectures will not produce human-level AI, though enterprise and consumer inference demand protects foundational infrastructure from immediate obsolescence. - [23:26](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1406s) The gap between impressive lab demos and reliable production systems mirrors historical pitfalls like IBM Watson and the 1980s expert systems collapse. - [29:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1777s) Four essential capabilities define real intelligence: physical world understanding, persistent memory, authentic reasoning, and goal-directed planning. - [31:58](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1918s) Artificial General Intelligence will not emerge overnight from an isolated startup, but will require years of iterative, open scientific discovery across the global research ecosystem. - [33:19](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1999s) Fixing common physical reasoning errors in models via supervised post-training is brittle and fails against the infinite long tail of real-world physical dynamics. - [36:28](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2188s) While frontier models ingest 10¹⁴ bytes of text across 400,000 human reading years, a four-year-old child processes the same byte volume of rich sensory data in just 16,000 waking hours. - [40:44](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2444s) Video generation systems do not comprehend physics; attempting to predict future frames at the pixel level forces models to model chaotic noise rather than underlying causal reality. - [43:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2613s) Autoregressive self-supervised learning works on text due to discrete token vocabularies, but becomes mathematically intractable when applied to high-dimensional continuous video spaces. - [49:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2940s) The Joint Embedding Predictive Architecture (JEPA) avoids pixel generation by predicting abstract latent representations, discarding unpredictable noise while capturing fundamental scene dynamics. - [53:06](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3186s) Action-conditioned JEPA models establish true planning and reasoning by chaining abstract future state predictions to search for optimal action sequences. - [54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) Open-source development moves faster than proprietary silos because no single entity holds a monopoly on breakthrough ideas or can centralize all global research talent. - [56:39](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3399s) Historic deep learning milestones like ResNet from Beijing and LLaMA from Paris illustrate that cutting-edge AI breakthroughs are decentralized and not exclusive to Silicon Valley.

## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=0s) Introduction and the Mystery of Missing Scientific Discoveries

Alex Kantrowitz opens the show by asking why generative AI models, despite having absorbed the entirety of written human knowledge, have yet to produce an original scientific discovery of their own, and whether these systems are finally learning how the physical world works. He welcomes Turing Award laureate and Meta Chief AI Scientist Yann LeCun to discuss the fundamental limits of the current AI paradigm.

Kantrowitz presents a challenge first raised by Dwarkesh Patel: if generative AI models have memorized basically the entire corpus of human knowledge, why haven't they made even a single novel connection leading to a scientific breakthrough? A moderately intelligent human with that volume of memorized facts would easily notice cross-domain patterns—such as observing shared symptoms across disparate conditions to deduce a medical cure.

```mermaid flowchart TD accTitle: LLM Limitations vs True Scientific Discovery accDescr: Diagram illustrating how current LLMs process text through memorization and retrieval compared to the human scientific discovery process.

subgraph LLMApproach["Current LLM Architecture"] A["Text Corpus Memorization"] --> B["Statistical Pattern Matching"] B --> C["Token Retrieval & Output Generation"] C -.->|"Fails at"| D["Original Hypotheses & New Insights"] end

subgraph HumanDiscovery["Human Scientific Discovery"] E["Abstract Mental Models"] --> F["Questioning Axioms & Assumptions"] F --> G["Formulating Problems & Equations"] G --> H["Novel Discoveries"] end ```

LeCun responds immediately that while we should expect breakthroughs from AI in the broader sense, we should not expect them from large language models (LLMs). Society has conflated the entirety of artificial intelligence with chat-driven LLMs. In reality, LLMs are trained strictly on text to regurgitate, retrieve, and output sequences that match the statistical properties of their training data. While useful, they also hallucinate false facts and are fundamentally unsuited for original invention:

> “Well, from AI yes, from large language models no.” — Yann LeCun > > “They really in their purest form, they are incapable of inventing new things.” — Yann LeCun

[01:55](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=115s) Why LLMs Cannot Become "Einstein in a Data Center"

Kantrowitz brings up an argument shared on LinkedIn by Thomas Wolf of Hugging Face, who noted that building an "Einstein in a data center" requires far more than knowing existing answers. It requires a system that questions consensus, writes "what if everyone is wrong about this?", and asks queries nobody else has dared to articulate when textbooks and experts dictate otherwise. Kantrowitz asks if an LLM can be taught to operate this way, to which LeCun answers with an emphatic "no."

Future architectures that achieve this will not be LLMs, though an LLM might serve as a modular subcomponent. LeCun draws an anatomical parallel to human cognition: in the human brain, language production is handled by Broca's area, a localized patch of tissue. That is our biological LLM. Yet humans do not actually think in language; thought occurs via underlying mental representations and internal world models that exist independently of speech. Even people unable to speak can think.

LeCun explains that research demands distinct, non-overlapping cognitive skills: - **Retrieval & Memorization:** The ability to retain and recall vast libraries of existing information (what LLMs excel at, akin to recalling an obscure equation solved a century ago). - **Problem Solving & Execution:** Taking a well-defined prompt or set of constraints and solving it mathematically or logically (the skill tested in school exams). - **Framing & Questioning:** The hardest aspect of scientific discovery, which involves questioning assumptions, seeing novel conceptual angles, and deciding which questions are actually worth asking.

Current language models perform only the first task. They cannot solve fundamentally new problems outside their training distribution, and they cannot formulate the right questions to challenge established paradigms:

> “To create an Einstein in a data center, we don't just need a system that knows all the answers, but rather one that can ask questions nobody else has thought or dared to ask, one that writes 'what if everything everyone is wrong about this' when all textbooks, experts, and common knowledge suggest otherwise.” — Thomas Wolf (quoted by Alex Kantrowitz) > > “In the human brain, that's done by a tiny little brain area right here called the Broca's area... that's our LLM, okay, but we don't think in language, we think in mental representations of a situation.” — Yann LeCun

[05:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=340s) The Flaws of Reasoning via Chain of Thought and Token Space

The discussion shifts to modern "reasoning models" that use step-by-step thinking. Kantrowitz asks whether one could program counterintuitive, heretical thinking simply by instructing a reasoning model to question its directives. LeCun clarifies what reasoning actually entails and dismisses the notion that current approaches represent a true reasoning breakthrough. Rather than shifting paradigms, the field is merely bolting crude patches onto autoregressive LLMs.

Techniques like Chain of Thought prompt the model to generate superfluous tokens so it spends more compute on an answer. While this produces superficial improvements, LeCun emphasizes that it is not authentic reasoning. In classical computer science and AI, reasoning entails searching through a structured space of candidate solutions against an explicit verification criteria. Generating a stream of text tokens and using an external verifier to pick the best output is as inefficient as writing software by randomly stringing together grammatically valid code instructions and hoping one executes properly.

```mermaid flowchart LR accTitle: Token Space Generation vs Abstract Mental Planning accDescr: Contrast between how LLMs attempt reasoning via text tokens versus how humans manipulate continuous mental models.

subgraph TokenSpaceApproach["LLM Token-Space Search"] direction TB T1["Generate Candidate Text Sequences"] --> T2["External Verifier Checks Tokens"] T2 --> T3["Select Best Guess"] end

subgraph AbstractModelApproach["Human Abstract Reasoning"] direction TB M1["Internal World Model"] --> M2["Continuous Mental Simulation"] M2 --> M3["Direct Plan Formulation"] end ```

Crucially, neither humans nor animals reason in "token space." When a person plans how to assemble a table, they do not churn through competing linguistic descriptions; they manipulate continuous spatial representations in their mind. LeCun offers a concrete visual thought experiment: imagine a cube hovering in the air and rotate it 90 degrees around its vertical axis. A person instantly knows the resulting shape looks identical to the original cube without using words or generating text. Because LLMs lack internal world models and operate purely on discrete text tokens, they cannot replicate this basic cognitive feat:

> “Can you bolt a couple widgets on top of an LLM so that you kind of have some primitive reasoning function? And that's essentially what a lot of reasoning systems are doing.” — Yann LeCun > > “Reasoning at least in classical AI is in many domains involves a search through a space of potential solutions... there is no mechanism at all in LLMs for this search mechanism.” — Yann LeCun > > “When humans or animals reason, we don't do it in token space... We reason internally, right? We have a mental model of the situation, and we manipulate it in our head, and we find kind of a good solution.” — Yann LeCun

Kantrowitz notes that when DeepSeek's reasoning model was released, users were captivated by viral screenshots of the model generating philosophically deep reflections on the human condition. Yet, as LeCun's critique illustrates, this is another clever illusion produced by autoregressive statistical association rather than genuine introspection or conceptual understanding.

[10:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=640s) Diminishing Returns and the Need for a New AI Paradigm

Alex Kantrowitz reflects on reading through chain-of-thought outputs, remarking that the reasoning often feels less like genuine thought and more like the model simply read Yuval Noah Harari's *Sapiens* alongside a few other books and regurgitated the text. Yann LeCun agrees with that characterization, saying, “pretty much yeah I mean yeah a lot of it is regurgitation.” Moving into a core question, Kantrowitz asks whether training conventional large language models is hitting a wall—shifting away from the historical predictability where pumping in more compute and more data reliably yielded better performance.

```mermaid flowchart TD accTitle: Limits of LLM Scaling vs New Architecture Needs accDescr: Diagram contrasting current LLM scaling challenges with the requirements of a next-generation architecture.

subgraph LLMLimits["Current LLM Paradigm: Diminishing Returns"] A["10¹³ – 10¹⁴ Internet Tokens<br>(Public text exhausted)"] --> B["Synthetic Data & Human Annotators<br>(Ballooning costs)"] B --> C["Core Weakness: Superficial Pattern-Matching<br>(No real logic or novel planning)"] end

subgraph NewArchitecture["Required New Paradigm"] D["World Model & Commonsense Physics"] --> E["Zero-Shot Problem Solving & Goal Search"] E --> F["True Agentic Systems<br>(Internal action planning & verification)"] end

C -.->|"Paradigm shift required"| D ```

LeCun clarifies that while he might not label it a hard wall, the approach is unmistakably facing diminishing returns. The industry has effectively run out of natural human text: current LLMs are already trained on $10^{13}$ to $10^{14}$ tokens, representing practically the entire publicly available internet. Companies are now turning to licensed private content, synthetic data generation, and hiring thousands of subject-matter experts, PhDs, and professors to manually plug holes in models' knowledge bases. Yet LeCun emphasizes that these stopgaps tackle the wrong issue, because the systems fundamentally fail to grasp basic logic. As LeCun puts it:

> “The costs are ballooning of generating that data and the the returns are not that great so we need a new paradigm.”

To build truly agentic systems, AI cannot merely regurgitate pre-existing plans; it requires a fundamentally different architecture built around searching for candidate solutions, verifying their validity, and planning multistep actions to reach explicit goals. LeCun points out that while everyone in tech hypes agentic workflows, nobody currently knows how to build them beyond recycling sequences already present in the training set.

---

[13:30](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=810s) Zero-Shot Problem Solving and Kahneman's System 1 vs. System 2

Contrasting current models with biological intelligence, LeCun observes that both humans and animals routinely encounter completely unfamiliar situations and resolve them either zero-shot or after minimal practice, drawing solely on their intuitive grasp of how the physical world operates. For instance, a human learns to drive a car with only a couple dozen hours of practice. LeCun links this to Daniel Kahneman's dual-process framework:

- **System 2 (deliberative and focused):** During a novice's first driving sessions, full mental bandwidth is required. The driver consciously models hazards, maps maneuvers, and imagines worst-case scenarios. - **System 1 (automatic and subconscious):** After roughly 20 to 30 hours behind the wheel, driving becomes second nature. A driver can comfortably hold a conversation because the task has transitioned into an automatic, subconscious reflex.

To illustrate how expertise transforms deliberation into reflex, LeCun shares a personal memory from an academic workshop:

> “I have this vivid memory of once being in a workshop where one of the participants was a chess grandmaster and he played a simultaneous game against like 50 of us right, you know going from from one person to another, you know I got wiped out in 10 turns or something, I'm terrible at chess right, but so he would come, you know come to my my table and, you know, had time to think about this cuz he, you know, he was playing the other 50 tables or something, so I make my move in front of him, he goes like 'what?' and then immediately plays, so he doesn't have to think about it. I was not a challenging enough opponent that he had to actually call his System 2; his System 1 was sufficient to beat me.”

LeCun points out that every task humans master initially demands the full, deliberate power of our minds before being compiled down into subconscious routines. The defining capability of human and animal cognition is the ability to confront an unprecedented scenario, reason through a sequence of novel actions, and satisfy a goal using common-sense world knowledge—precisely what modern AI systems lack.

---

[16:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=989s) "A PhD Next to You" vs. Capital Expenditure Realities

Kantrowitz presses LeCun on the profound financial stakes and timeline mismatch facing the industry. Enormous venture sums have poured into LLM-first companies—$6.6 billion into OpenAI, multiple rounds totaling over $7.5 billion into Anthropic, and vast resources into Elon Musk's xAI for Grok. If scaling existing models is yielding diminishing returns while the research for a replacement paradigm remains unsolved and years away, Kantrowitz asks whether the tech sector is marching straight into an investment crisis.

LeCun responds unequivocally on the limits of current approaches:

> “The first thing you can say is we are not going to get to human-level AI by just scaling up LLMs, this is just not going to happen.”

LeCun dismisses aggressive forecasts made by certain peers, calling the notion that industry will deliver "a country of geniuses in a data center" within two years "complete BS" and stating there is "absolutely no way in hell." While massive parameter counts and vast datasets will produce systems capable of answering virtually any common query—creating the illusion of having a PhD at one's side—LeCun cautions that this illusion is merely an extraordinary retrieval engine over a gigantic memory bank. True doctoral-level intelligence requires inventing brand-new solutions to unsolved problems, an ability absent in pure autoregressive models (referencing a point highlighted by researcher Tom Walsh).

Defending Meta's heavy infrastructure spending, LeCun explains that their immense capital expenditure is aimed at inference operations rather than pure speculative model training:

- Meta's objective is to serve over 1 billion users interacting with Meta AI by year-end across smart glasses, standalone applications, and integrated social products. - Powering persistent daily use for hundreds of millions of users requires immense compute clusters and data center investments that must be constructed months or years in advance. - Even if a breakthrough to a post-LLM paradigm does not arrive within the next three years, the demand to run consumer-scale inference across Meta, Microsoft, Google, and Amazon will fully absorb this computational capacity, preventing the infrastructure buildout from being rendered obsolete.

[21:13](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1273s) Consumer Scale vs. the Enterprise Reliability Barrier

Alex Kantrowitz highlights the current tension between massive capital expenditure and real-world utility. Setting up data centers requires years of forward-looking planning, forcing tech giants to invest heavily because they simply cannot afford to miss out if progress remains continuous. Kantrowitz contrasts consumer adoption with enterprise realities: OpenAI boasts 400 million users for ChatGPT, while Meta commands an install base across its family of apps in the billions, converting roughly 600 million users to Meta AI. While Meta AI's engagement may not yet match the intensity of ChatGPT, getting toward a billion consumer users is plausible.

```mermaid flowchart LR accTitle: The Enterprise Adoption Funnel accDescr: Proof of concept stages fail to graduate into production deployments due to accuracy and cost constraints.

subgraph Labs["Exploration Stage"] A["Enterprise POCs (100%)"] end

subgraph Roadblock["Deployment Barriers"] B["Hallucinations (5% error rate)"] C["High Compute & Run Costs"] end

subgraph RealWorld["Production"] D["Shipped to Production (10–20%)"] end

A --> B A --> C B --> D C --> D ```

However, Kantrowitz points out that the vast majority of AI investments depend on enterprise adoption, where current systems stumble. Referencing an argument from Benedict Evans regarding tools like Deep Research, he notes that an AI system achieving 95% accuracy leaves a fatal 5% hallucination rate. In a 100-page business report, an executive cannot afford to guess which 5% is fabricated. Consequently, across the corporate world, only about 10% to 20% of enterprise proof-of-concept projects graduate into live production; they are simply too fallible or too expensive to operate. Kantrowitz presses Yann LeCun on what happens if the industry hits a performance ceiling when so much capital was deployed expecting unbroken upward trajectories.

- Meta leverages a user base of over 3 billion mobile users to capture roughly 600 million Meta AI users. - OpenAI has reached an estimated 400 million ChatGPT users with deeper per-user session intensity. - Only an estimated 10% to 20% of enterprise generative AI proofs of concept make it into production environments. - Deep research tools delivering 95% accuracy present major operational risk because users cannot identify which 5% contains errors.

---

[23:26](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1406s) The Last Mile Problem and the Ghost of IBM Watson

Yann LeCun contextualizes the enterprise struggle as an enduring problem in computing history, emphasizing that moving beyond an impressive lab demonstration to a dependable production system is where AI projects historically break down. He draws a direct parallel to autonomous vehicles: despite dazzling demos a decade ago, fully autonomous Level 5 self-driving cars remain unrealized because closing the "last mile"—the final fractions of a percent required for true safety and reliability—proves exponentially harder than the initial progress.

To illustrate how corporate AI hype can unravel, LeCun points to IBM Watson. IBM positioned Watson to generate billions in revenue by having it ingest the medical literature to serve as an automated diagnostician in every hospital. Instead, Watson struggled in complex clinical settings, failed to mesh with existing workflows, ran up against the natural conservatism of the medical workforce, cost IBM vast sums of money, contributed to executive turnover, and was ultimately dismantled and sold off for parts. LeCun stresses that this cycle of enterprise friction is not a novel symptom of generative AI:

> “The process we're seeing now with the difficulty of deploying a system is not new; it's happened absolutely at all times.”

He notes that current LLMs still provide clear, practical value—especially for internal retrieval-augmented generation (RAG) tasks across corporate intranets. Within Meta, employees rely daily on an internal knowledge-base retrieval tool called Metamate, which indexes company documentation so staff can query organizational data.

---

[25:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1537s) Expert Systems, AI Winters, and Timeline Mismatches

LeCun recalls the 1980s boom in expert systems to warn about recurring industry patterns. Back then, "knowledge engineer" was hailed as the definitive career of the future. The job required sitting beside human experts, converting their heuristics into structured symbolic rules and facts, and feeding them into inference engines. The hype reached geopolitical levels, prompting the Japanese government to pour vast funding into its Fifth Generation Computer Systems project to build specialized hardware architectures. Yet by the mid-1990s, the entire wave collapsed into an AI winter. The economic feasibility was restricted to a handful of narrow, rule-bound problems, failing completely to deliver wide-ranging societal transformation.

Kantrowitz picks up on these historical cycles, noting that he and LeCun first spoke nine years ago about the long journey LeCun experienced alongside Yoshua Bengio, Geoffrey Hinton, and others. For years, connectionist neural network ideas were rejected and shut out from mainstream academic conferences until sufficient compute caught up to validate the architecture. Kantrowitz asks whether the combination of massive capital expenditures, diminishing returns from pure LLM scaling, and broader stock market volatility threatens to plunge the tech sector into another major AI backlash and winter.

- The 1980s expert system boom drove the Japanese Fifth Generation Computer project before collapsing in the mid-1990s. - Knowledge engineers spent years manually interviewing domain specialists to build rigid rule-based inference engines. - Connectionist architectures developed by pioneers like Yann LeCun, Yoshua Bengio, and Geoffrey Hinton were largely ignored by mainstream computer science until modern compute made deep learning viable.

---

[29:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1777s) The Four Missing Pillars of True Intelligence

Addressing investor expectations, LeCun is blunt about the peril of banking solely on existing paradigms. He argues that anyone expecting current transformer architectures to reach human-level cognition purely by ingesting more tokens and applying minor tweaks is operating under a profound delusion:

> “If you're an investor and you invested in a company that told you we're going to get to human-level AI and PhD level by just, you know, training on more data and with a few tricks, I don't know if you're going to lose your shirt, but that was probably not a good idea.”

Real cognitive intelligence, LeCun insists, requires four foundational pillars present in nearly every animal but utterly absent in current large language models:

1. **Understanding the physical world** 2. **Persistent memory** 3. **The ability to reason** 4. **The ability to plan actions toward goals**

```mermaid flowchart TD accTitle: The Four Pillars of True Intelligence accDescr: LeCun's four fundamental requirements for autonomous intelligent systems.

subgraph CorePillars["Essential Cognitive Capabilities"] P1["1. Physical World Understanding<br>(Sensory grounding via video)"] P2["2. Persistent Memory<br>(State retention over time)"] P3["3. Reasoning<br>(Logic beyond token prediction)"] P4["4. Planning<br>(Mental simulations to achieve goals)"] end

CorePillars --> CommonSense["Common Sense & Autonomous Agency"] ```

Acquiring common sense demands training on raw perceptual streams—such as video—rather than exclusively on human-authored text. LeCun notes that research teams across Meta, Google DeepMind, and top academic institutions are actively pursuing systems that build internal mental models of physics to simulate and plan actions toward explicit goals. While early experimental results are beginning to surface in academic papers, scaling these world-model architectures into reliable, general-purpose systems will not happen overnight. He estimates that translating these proofs of concept into scalable, practical architectures capable of solving novel problems will take between three to five years rather than occurring in the immediate future.

[31:58](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1918s) The Illusion of an AGI "Magic Bullet" and the Open Research Community

Yann LeCun contextualizes the ongoing surge of artificial intelligence investment, cautioning that true general intelligence will not arrive overnight through some proprietary breakthrough. He stresses that artificial general intelligence is not going to be a singular, binary threshold where one day it does not exist and the next day it does. Instead, advancing AI requires steady, continuous conceptual breakthroughs developed by the global scientific community over years, scaling up ideas that prove sound while abandoning dead ends. LeCun argues that open collaboration will inevitably outpace closed silos, warning investors against being seduced by overhyped claims from secretive small teams.

Alex Kantrowitz reflects on how much he values LeCun’s perspective as an empirical grounding point against industry hype, noting that past conversations have consistently held up over time. Setting up the next leg of their discussion, Kantrowitz points out two critical threads emerging from LeCun’s worldview: building an actual understanding of physical reality and the necessity of open-source research.

> “And so if you think that there is some startup somewhere with five people who has discovered the secret of AGI and you should invest five billion in them, you're making a huge mistake.” — Yann LeCun

- Progress in AI relies on distributed scientific contributions across the global research ecosystem rather than proprietary discovery by a single company. - Entities that openly publish and share their findings advance faster than closed development environments. - Investors pouring billions into small startups under the premise that an isolated team holds the singular key to AGI are fundamentally misjudging how science progresses.

---

[33:19](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1999s) The Paper Test: Post-Training Patches vs. True Physical Intuition

Kantrowitz revisits a memorable test from their podcast two years prior: asking ChatGPT what happens if you hold a piece of paper horizontally with both hands and let go with your left hand. Back then, ChatGPT confidently hallucinated that the paper would magically float toward the left hand, and Kantrowitz had read the erroneous answer aloud before LeCun pointed out the obvious physics failure. Testing the prompt again two years later, Kantrowitz finds the model now answers correctly, explaining that gravity pulls the left side down while the right side creates a pivot effect.

LeCun is unimpressed by the model's new response, explaining that this fix is almost certainly the result of post-training and supervised fine-tuning rather than genuine physical reasoning. An engineer or annotator at OpenAI likely encountered that exact prompt, fed the system the correct answer, and fine-tuned it into the weights. Because the real world contains an infinite variety of physical interactions, brute-force fine-tuning will inevitably fail along the long tail of human experience. Post-training becomes exorbitant and brittle when developers try to manually patch every blind spot.

> “You cannot cover the set of all possible questions in the training set.” — Yann LeCun

- **The original failure:** Two years earlier, ChatGPT asserted that letting go of a horizontally held sheet of paper with the left hand would cause the paper to float toward that hand. - **The updated response:** Modern versions correctly state that gravity causes the left side to drop while pivoting around the right hand. - **Post-training limitations:** Manually patching common failure modes fails to address the infinite long tail of physical scenarios that cannot be covered in training data.

---

[36:28](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2188s) Video Generation and the Data Reality: Toddlers vs. Trillion-Token Models

Kantrowitz asks whether modern video generation models like OpenAI's Sora demonstrate an emergent grasp of physics, noting that generating a prompt of a man kicking his legs while seated on a chair yields anatomically consistent legs that bend at the joints without hallucinating extra limbs. LeCun dismisses this as an optical illusion of comprehension. Video generators still routinely produce physics anomalies, such as spilled wine floating upward, flying off, or vanishing into thin air. Adding massive datasets to patch isolated video scenarios merely compensates for an absence of real understanding.

```mermaid flowchart TD accTitle: Training Data Volume Comparison accDescr: Comparison of sensory byte volume between Large Language Models, four-year-old children, and infant learning milestones.

subgraph LLM["Large Language Models"] T["30 Trillion Tokens"] -->|"~3 bytes per token"| B1["~10¹⁴ Bytes of Text"] B1 --> R["Requires ~400,000 years for a human reading 12 hrs/day"] end

subgraph Child["Human Sensory Intake"] V["16,000 Awake Hours (Age 4)"] -->|"2 MB/s via optic nerves"| B2["~10¹⁴ Bytes of Vision/Touch"] V2["9-Month-Old Infant"] -->|"~10¹³ Bytes of Vision"| B3["Intuitive Physics Acquired"] end ```

To demonstrate why text alone can never achieve human-level intelligence, LeCun presents a quantitative comparison between large language models and human sensory development. While an LLM ingests an enormous amount of text that would take a human 400,000 years to read, a four-year-old child processes an equivalent volume of sensory data in just 16,000 waking hours. Furthermore, a nine-month-old infant masters core intuitive physics with an order of magnitude less data than that.

> “In four years a child has seen through vision or touch for that matter as much data as the biggest LLMs, and it tells you clearly that we're not going to get to human level by just training on text.” — Yann LeCun

- **LLM data scale:** A typical frontier model trained on 30 trillion tokens processes roughly $10^{14}$ bytes of text, representing 400,000 years of reading at 12 hours per day. - **Child sensory bandwidth:** The human optic nerves carry roughly 2 megabytes per second (1 MB/s per nerve). Over 16,000 waking hours in a child's first four years, the visual cortex ingests approximately $10^{14}$ bytes. - **Infant physical mastery:** In just nine months (roughly $10^{13}$ bytes of sensory input), an infant learns foundational concepts of intuitive physics, including gravity, momentum conservation, and object permanence. - **Video context:** The 16,000 hours of video a child sees in four years equates to just 30 minutes of total video uploaded to YouTube.

---

[40:44](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2444s) Why Generative Pixel Prediction Fails to Build a World Model

LeCun argues forcefully against the prevailing industry trend of using video generation to create world models. The objective of an intelligent system is not to generate high-fidelity, pixel-by-pixel simulations of the future, but to understand what actions are possible and predict outcomes at an appropriate level of abstraction. Predicting every minute detail of the physical world is both impossible and unnecessary for functional intelligence.

Using the everyday example of spilling a cup of water, LeCun points out that no human can calculate the precise trajectory of every water droplet, the exact splatter shape on the table, or the specific acoustic frequency produced. However, human abstract reasoning immediately anticipates the essential consequence: the water will spill, ruin documents, and soak a nearby smartphone. To plan actions toward goals, an AI architecture must abandon pixel-level generative objectives and instead learn abstract world representations that discard irrelevant noise.

> “The problem of understanding the world does not go through the solution to generating video at the pixel level.” — Yann LeCun

- **Generative limitations:** Predicting individual pixels forces models to waste computational capacity on chaotic, unpredictable details rather than underlying reality. - **Abstract world models:** True comprehension requires predicting state changes at an abstract level to evaluate cause and effect. - **Non-generative architectures:** Architectures designed to comprehend physical reality and plan actions must be non-generative, focusing entirely on structural and causal representations.

[42:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2549s) Why Video Generation Fails at Physics

Alex Kantrowitz recounts an experiment he ran using a state-of-the-art video generation model to test its grasp of real-world physics. First, he asked it to depict a man sitting on a chair kicking his legs out. To Kantrowitz's surprise, the legs stayed attached to the torso throughout the motion, making him think the technology had made a real leap forward. But when he tested an edge case—prompting for a car driving into a haystack—the illusion completely fell apart: two stationary bales of hay appeared, and suddenly a haystack magically emerged straight out of the car's hood. Kantrowitz laughs that his immediate reaction was, “okay Yann, Yann wins again.”

Yann LeCun explains that this discrepancy stems directly from the training data distribution. AI labs fine-tune video generators with massive amounts of footage of humans performing everyday actions because human prompts represent the vast majority of consumer requests. The models perform passably when recreating human bodies simply because they have memorized an abundance of examples. However, as soon as a user introduces an unfamiliar physical interaction that the creators never anticipated—like a vehicle plowing into farm bales—the system hallucinates nonsensical physics because it possesses no underlying world model.

- Video models succeed on human motion primarily due to heavy fine-tuning on vast datasets of people. - Kantrowitz’s haystack test demonstrates how generative video models break down when facing unrepresented physical interactions. - “The thing is those systems have been fine-tuned with a huge amount of data for humans because, you know, that's what people are asking most videos they ask for.” — Yann LeCun

---

[43:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2613s) Self-Supervised Learning: Why Generative Prediction Works for Text but Fails for Video

Kantrowitz asks how non-generative architectures like V-JEPA (Video JEPA) and I-JEPA (Image JEPA) can solve the problem of abstract representation. LeCun steps back to explain self-supervised learning, the foundational paradigm powering both modern LLMs and computer vision breakthroughs. In self-supervised learning, an unlabelled input—whether text, an image, or a video—is partially corrupted or masked, and a large neural network is trained to recover the original or predict the missing piece. LLMs represent a specialized, causal variant of this concept: by restricting the neural network so that it can only look at tokens to its left, the model learns to predict the next word in an autoregressive sequence without needing manual human annotations.

```mermaid flowchart LR accTitle: Causal Autoregressive Text Generation accDescr: Diagram showing how a causal language model predicts the next token from past tokens and feeds it back into the input. subgraph InputTokens["Input Tokens"] T1["Token 1"] --> T2["Token 2"] T2 --> T3["Token 3"] end subgraph Model["Causal Architecture"] T3 --> LLM["LLM Layer"] end subgraph Prediction["Next Token"] LLM --> T4["Token 4 (Argmax/Sample)"] T4 -.->|"Autoregressive Loop"| InputTokens end ```

While autoregressive reconstruction works remarkably well for text, LeCun emphasizes that applying the same reconstruction strategy to computer vision—such as Masked Autoencoders (MAE) for static images or generative frame prediction for video—hits a hard mathematical wall. In natural language processing, the space of possibilities at any given step is finite and discrete; an LLM simply outputs a probability distribution over a vocabulary of roughly 100,000 distinct tokens. In video, however, predicting the exact raw pixels of future frames requires modeling probability distributions across continuous, infinitely dimensional spaces. Because real-world futures contain endless irreducible details, generative video models are mathematically ill-equipped to serve as world models.

- Self-supervised learning masks or distorts raw input data and trains networks to reconstruct the uncorrupted state without manual labels. - LLMs are causal self-supervised models constrained to look only at past tokens to predict the subsequent token autoregressively. - Vocabulary distributions in language models are simple categorical vectors summing to 1 across roughly 100,000 discrete tokens. - “In fact, it's mathematically intractable to represent distributions in high-dimensional continuous spaces.” — Yann LeCun - “This is why, you know, trying to train a video generation system as a way to get a system to understand how the world works—that's why it can't succeed.” — Yann LeCun

---

[49:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2940s) Inside JEPA: Learning Abstract World Models via Joint Embeddings

To bypass the pitfalls of pixel generation, LeCun advocates for the Joint Embedding Predictive Architecture (JEPA). Instead of trying to reconstruct missing pixels, JEPA extracts representations of both the original input and the corrupted input using neural encoders. A predictive model then operates entirely within this abstract latent space, attempting to predict the feature representation of the complete input from the representation of the partial input. By optimizing in embedding space rather than pixel space, the network naturally learns to discard unpredictable visual noise while retaining the fundamental invariants of the scene.

```mermaid flowchart TD accTitle: JEPA Architecture Flow accDescr: Diagram showing how JEPA processes full and corrupted inputs through encoders and predicts representations in latent space. subgraph Processing["Encoder Pathways"] Full["Full Video / Image (x)"] --> Enc1["Encoder"] Enc1 --> RepFull["Latent Representation: s(x)"] Corr["Corrupted / Masked Input (y)"] --> Enc2["Identical / EMA Encoder"] Enc2 --> RepCorr["Latent Representation: s(y)"] end subgraph LatentPrediction["Abstract Prediction"] RepCorr --> Pred["Predictor"] Pred --> PredState["Predicted State: s'(x)"] PredState <-->|"Loss Minimization (Prediction Error)"| RepFull end ```

LeCun illustrates this principle using a vertical pen balanced on a desk: when released, the exact direction it tips over is physically chaotic and impossible to forecast down to the exact pixel, yet at an abstract level, one can easily predict with certainty that the pen is going to fall. Meta's research team is exploring several non-contrastive training algorithms for these joint embeddings, including DINO, VICReg (Variance-Invariance-Covariance Regularization), and I-JEPA. When applied to video (V-JEPA), the architecture excels at identifying high-level semantics—such as recognizing specific human actions or detecting impossible physical events generated by game engines, such as objects vanishing or rolling balls disappearing behind barriers, simply by monitoring the spike in the system's latent prediction error.

- JEPA compares embeddings rather than raw sensory inputs, preventing models from wasting capacity on chaotic, unpredictable details. - Training methods being explored for JEPA include DINO, VICReg, and distillation architectures like I-JEPA. - V-JEPA evaluates physical plausibility by measuring prediction error when objects abruptly vanish, pass through solid matter, or mutate unnaturally. - “It's not generative because the system is not trying to regenerate the part of the input; it's trying to generate an abstract representation of the input.” — Yann LeCun - “The pen that you put on the table vertically, and when you let it go you cannot predict in which direction it's going to fall, but at some abstract level you can say that the pen is going to fall.” — Yann LeCun

[53:06](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3186s) Action-Conditioned JEPA and Genuine Planning

When a self-supervised world model is trained on natural, physically plausible video, it builds an internal baseline for how reality behaves. If something physically impossible occurs in a test video, the system's prediction error spikes immediately, providing a measurable signal that the model has internalized physical constraints and acquired rudimentary common sense. Yann LeCun explains that Meta has extended these architectures into "action-conditioned" systems. In this framework, the model takes a representation of the world's state at time $t$ along with a proposed action—such as an instruction to actuate a robotic arm—and predicts the resulting state at time $t+1$ purely inside an abstract representation space rather than predicting raw, pixel-level frames.

```mermaid flowchart LR accTitle: Action-Conditioned JEPA Planning Architecture accDescr: Diagram illustrating how an action-conditioned JEPA world model predicts future abstract states and searches for action sequences to reach a goal. subgraph Input["Current State & Action"] S0["State at time t"] A0["Action"] end subgraph Model["JEPA World Model"] WM["Abstract Predictor"] end subgraph Prediction["Future State & Evaluation"] S1["Predicted State at time t+1"] Plan["Search & Goal Evaluation"] end S0 --> WM A0 --> WM WM --> S1 S1 --> Plan ```

By chaining these abstract predictions together, the model can simulate the future and mentally test hypotheses. An operator can provide a target state—specifying what the world should look like at the end of a task—and the model can conduct a search over possible action sequences to determine which steps will successfully achieve that target. LeCun emphasizes that this capability represents the foundational architecture for authentic machine intelligence, contrasting it with simple text extrapolation: “That's planning that's reasoning that's actual reasoning and actual planning.”

[54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) Open Source, DeepSeek, and Global AI Innovation

With time running out on the interview, Alex Kantrowitz asks LeCun for a rapid-fire reaction to DeepSeek and whether open-source AI has officially overtaken proprietary frontier models. LeCun hesitates to use the word "overtaken," pointing out that proprietary AI labs immediately absorb and benefit from whatever the open-source community publishes. However, he stresses that the pace of innovation within open source is inherently faster because proprietary labs cannot match the collective brainpower of the broader research ecosystem. Pointing to DeepSeek's recent triumphs, LeCun observes: “Nobody has a monopoly on good ideas and so the magic efficiency of the open source world is that it recruits talents from all over the world.”

When given a long leash and minimal bureaucratic constraints, small, agile research teams can rethink standard practices and invent model architectures that legacy frontier labs overlook. Once those insights are shared publicly, the entire global scientific community leaps forward together. LeCun also highlights the economic reality driving enterprise adoption: while corporate partners frequently experiment and prototype using proprietary closed APIs, they routinely shift production deployments to open-source foundations like Llama. Open weights offer drastically lower inference costs, tighter data security, granular customization, and the indispensable ability to run systems on-premises.

- Progress moves faster across open source because no single corporation, regardless of size or budget, can assemble all global talent under one roof. - Proprietary software developers routinely benefit from open-source breakthroughs since all published techniques and model architectures are accessible to them. - Enterprise customers typically use proprietary cloud APIs for early-stage prototyping, but pivot to open-source models like Llama for production rollouts to reduce operating costs and retain operational control.

[56:39](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3399s) Shattering Geopolitical Myths: ResNet, Llama, and the Global Nature of Science

Addressing critics who fear that open-source AI will inadvertently help geopolitical rivals like China, LeCun dismisses the notion that overseas researchers depend on Western handouts. Top-tier scientific talent is distributed worldwide, and Chinese researchers have long produced seminal contributions to foundational AI. To illustrate this, LeCun cites ResNet (Residual Networks), published in 2015 out of Microsoft Research Beijing, which stands as the single most cited scientific paper in the history of science. ResNet revolutionized deep learning by introducing identity shortcut connections—allowing layers to learn deviations from an identity mapping rather than fitting full transformations from scratch—which enabled researchers to successfully train neural networks containing dozens or even hundreds of layers.

LeCun recalls hiring ResNet's lead author, Kaiming He, to join the FAIR (Fundamental AI Research) lab in California, where He worked for about eight years before taking a professorship at MIT. LeCun notes that breakthrough AI development is fundamentally decentralized: the original LLaMA model did not come out of Silicon Valley either, but was built by a tight-knit team of just twelve researchers at FAIR's lab in Paris. Kantrowitz and LeCun wrap up the discussion reflecting on their nine years of conversations cutting through industry hype. LeCun concludes with a defense of open international research: “You have to take advantage of the diversity of ideas backgrounds creative juices of the entire world if you want Science and Technology to progress fast and that's enabled by open source.”

- ResNet, published in 2015 by Kaiming He and colleagues at Microsoft Research Beijing, holds the title of the single most cited paper in all of science. - ResNet introduced skip connections that compute identity deviations, resolving gradient degradation and enabling stable training across networks exceeding 100 layers. - Kaiming He was recruited by LeCun to FAIR in California, conducted research there for roughly eight years, and subsequently joined the faculty at MIT. - The original LLaMA model was developed in Paris by a small FAIR team comprising only 12 researchers, demonstrating that cutting-edge AI breakthroughs do not originate exclusively within Silicon Valley.

## Notable quotes > [16:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=989s) The first thing you can say is we are not going to get to human-level AI by just scaling up LLMs, this is just not going to happen. — Yann LeCun

> [40:44](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2444s) The problem of understanding the world does not go through the solution to generating video at the pixel level. — Yann LeCun

> [36:28](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2188s) In four years a child has seen through vision or touch for that matter as much data as the biggest LLMs, and it tells you clearly that we're not going to get to human level by just training on text. — Yann LeCun

> [31:58](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1918s) if you think that there is some startup somewhere with five people who has discovered the secret of AGI and you should invest five billion in them, you're making a huge mistake. — Yann LeCun

> [54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) Nobody has a monopoly on good ideas and so the magic efficiency of the open source world is that it recruits talents from all over the world. — Yann LeCun

> [43:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2613s) In fact, it's mathematically intractable to represent distributions in high-dimensional continuous spaces. — Yann LeCun

## Mentioned Yann LeCun, Alex Kantrowitz, Dwarkesh Patel, Thomas Wolf, Hugging Face, DeepSeek, Yuval Noah Harari, Daniel Kahneman, OpenAI, ChatGPT, Anthropic, Elon Musk, xAI, Grok, Tom Walsh, Meta, Meta AI, Microsoft, Google, Amazon, Benedict Evans, Deep Research, IBM Watson, Metamate, Yoshua Bengio, Geoffrey Hinton, Google DeepMind, Sora, YouTube, V-JEPA, I-JEPA, DINO, VICReg, Llama, ResNet, Kaiming He, FAIR, MIT

## Video description Yann LeCun is the chief AI scientist at Meta. He joins Big Technology Podcast to discuss the strengths and limitations of current AI models, weighing in on why they've been unable to invent new things despite possessing almost all the world's written knowledge. LeCun digs deep into AI science, explaining why AI systems must build an abstract knowledge of the way the world operates to truly advance. We also cover whether AI research will hit a wall, whether investors in AI will be disappointed, and the value of open source after DeepSeek. Tune in for a fascinating conversation with one of the world's leading AI pioneers.

Chapters:

00:00 Introduction to Jan LeCun and AI's limitations 01:12 Why LLMs can't make scientific discoveries 05:40 Reasoning in AI systems: limitations of chain of thought 10:13 LLMs approaching diminishing returns and the need for a new paradigm 16:29 "A PhD next to you" vs. actual intelligent systems 21:36 Consumer AI adoption vs. enterprise implementation challenges 25:37 Historical parallels: expert systems and the risk of another AI winter 29:37 Four critical capabilities AI needs for true understanding 33:19 Testing AI's physics understanding with the paper test 37:24 Why video generation systems don't equal real comprehension 43:33 Self-supervised learning and its limitations for understanding 51:10 JEPA: Building abstract representations for reasoning and planning 54:33 Open source vs. proprietary AI development 58:57 Conclusion

[Source](https://www.youtube.com/watch?v=qvNCVYkHKfg)

中文简报

Meta首席AI科学家LeCun警告:单纯扩展大语言模型无法实现人类级别AI 语言模型因离散token预测缺乏内部世界模型而无法进行科学发现或推理,AI发展需转向基于感知训练的架构。 Yann LeCun指出,大语言模型从根本上无法做出真正的科学发现或达到人类级别的智能,因为它们完全依赖统计学上的token预测,而非对物理世界的内部心智模型。尽管业界对自回归文本和像素生成的规模扩展面临收益递减,且未能解决基本逻辑或规划问题,但一个四岁儿童仅通过丰富的感知数据、以极低的计算开销就能习得海量直觉物理学常识。LeCun提倡采用联合嵌入预测架构(JEPA)等非生成式架构,在抽象隐空间中预测行为,以实现真正的推理、验证和目标导向规划。最后,他强调技术进步不能受限于封闭的专有实验室,并坚称全球分布式的开源科学协作对长期技术进步至关重要。 Yann LeCun认为,大语言模型永远无法达到人类级别的智能或做出原创性科学发现,因为它们缺乏内部世界模型,纯粹依赖离散token检索运行,且在耗尽自然公开文本后正面临严重的收益递减。 (0:00) 真正的智能需要当前语言模型所欠缺的四大基石:对物理世界的理解、持久记忆、超越token空间生成的推理能力,以及规划朝向目标的行动序列的能力。 (29:37) 像Sora这样的像素级视频生成模型由于预测高维连续分布在数学上难以处理,无法作为真正的世界模型,因此必须采用诸如联合嵌入预测架构(JEPA)之类的非生成式架构。 (40:44) 企业采用生成式AI面临严重的最后一公里可靠性障碍,由于持续存在的5%幻觉率和高昂的推理成本,仅有10%到20%的概念验证项目能推进至生产阶段。 (21:13) 开源研究通过吸纳全球人才和分散创新从根本上超越封闭实验室,例如发源于北京的ResNet等奠基性突破,以及由巴黎一个12人团队开发的初代LLaMA模型。 (54:33)

Reading summary

Meta Chief AI Scientist Yann LeCun argues that autoregressive large language models cannot achieve human-level intelligence or make original scientific discoveries because text prediction lacks an internal model of the physical world. Reaching true intelligence requires shifting away from generative token matching toward non-generative architectures capable of abstract reasoning and goal-directed planning, developed through open, global scientific research. Why Token Prediction Cannot Produce Discovery (1:55) LeCun distinguishes memorization from genuine invention, comparing current language models to the human brain's Broca's area, which handles surface language production rather than the underlying mental models where thinking actually occurs. While LLMs excel at retrieving facts across vast training corpora, they cannot question established consensus, formulate unprompted hypotheses, or solve problems outside their training distribution. LeCun asserts that current reasoning models using Chain of Thought merely prompt the network to emit extra text tokens to burn more compute, creating an illusion of introspection. In contrast to human and animal cognition—which manipulates continuous, non-verbal spatial models—generating candidate tokens and filtering them through external verifiers is an inefficient substitute that fails to achieve authentic reasoning. Data Bottlenecks and Enterprise Production Failures (21:13) The current LLM paradigm is encountering diminishing returns as the industry exhausts the public internet's $10^{13}$ to $10^{14}$ tokens of natural human text, compelling labs to rely on costly synthetic data and manual expert annotation. Alex Kantrowitz and LeCun note that this fundamental ceiling creates severe commercial roadblocks. Although consumer tools scale rapidly, corporate adoption falters because an AI tool with 95% accuracy still produces a 5% hallucination rate, which enterprise workflows cannot tolerate. Consequently, only 10% to 20% of enterprise proofs-of-concept progress to live production. LeCun compares today's enterprise hype to the 1980s expert-systems bubble and IBM Watson's failed clinical diagnostic promises, cautioning that closing the final reliability gap in unstructured environments is exponentially harder than delivering initial laboratory demonstrations. Physical Grounding Versus Generative Video Prediction (36:28) LeCun contrasts artificial training efficiency with biological development: while frontier models ingest text that would take a human 400,000 years to read, a four-year-old child absorbs a comparable volume of sensory data ($10^{14}$ bytes) through vision and touch in just 16,000 waking hours, and a nine-month-old infant intuitively masters basic physics. However, LeCun rejects the idea that generative video models like Sora serve as world models. Predicting exact, continuous pixels across high-dimensional spaces is mathematically intractable and forces models to waste computational capacity on irrelevant microscopic noise. Video models appear competent only when reproducing heavily represented training scenarios like human movement, but immediately generate absurd physical anomalies when presented with unfamiliar interactions. Non-Generative World Models and Action Planning (49:00) To establish the four foundations of true intelligence—world understanding, persistent memory, reasoning, and planning—LeCun advocates for the Joint Embedding Predictive Architecture (JEPA). Rather than reconstructing raw pixels or predicting next tokens, JEPA extracts abstract representations of full and masked inputs, optimizing predictions entirely in latent space to discard chaotic visual noise while retaining essential physical invariants. By extending this into action-conditioned JEPA, a system can simulate how an action alters the world's abstract state and search through candidate sequences to achieve a target goal. LeCun identifies this internal simulation and search mechanism as the foundation of authentic planning, estimating that practical, scalable implementations will require three to five years to mature. The Strategic Necessity of Open Research (54:33) LeCun disputes the premise that artificial general intelligence can be unlocked in secret by small venture-backed startups, arguing that foundational advances rely on broad, distributed contributions across the international scientific community. Dismissing geopolitical concerns that open-source models empower foreign competitors at Western expense, LeCun notes that breakthrough research is inherently decentralized. He points out that ResNet, the most cited paper in scientific history, originated at Microsoft Research Beijing under Kaiming He, while Meta's original LLaMA architecture was developed by a 12-person team in Paris. Furthermore, LeCun observes that enterprise deployments steadily shift from closed cloud APIs toward open-source foundation models to ensure data privacy, lower inference costs, and provide on-premises operational control. LeCun maintains that human-level AI cannot be realized simply by scaling LLMs on larger datasets, projecting that building reliable, world-model-based reasoning architectures will require years of sustained open research. A central unresolved tension remains whether the tech industry's massive infrastructure expenditures can remain economically viable on consumer inference alone while enterprise production deployments face persistent hallucination barriers.

精炼阅读摘要

图灵奖得主、Meta首席AI科学家Yann LeCun指出,大语言模型本质上是通过自回归对既有文本进行统计匹配与检索,缺乏内在世界模型与规划能力,因而无法通过单纯扩大规模实现真正的科学发现或通用人工智能。 自回归大模型的认知局限与思维错觉 (0:00) LeCun认为,公众已将人工智能整体等同于基于聊天的语言模型,但纯粹的LLM根本无法做出原创发明。人类认知中负责语言输出的布罗卡区仅为局部脑组织,人类思考依靠的是独立于语言的心理表征与世界模型,而非在离散标记(token)空间中运作。针对以思维链(Chain of Thought)为代表的“推理模型”,LeCun批评这只是在自回归框架上硬拼接的简陋补丁,其生成的哲学反思实质是统计关联驱动的文本复述。经典计算中的推理需要针对明确验证标准在结构化空间中搜索可行解,单纯在标记空间生成候选序列并依赖外部验证器筛选,其效率如同随机拼凑代码以期望程序正确运行。 数据耗尽、边际效应与企业落地困境 (10:40) LLM范式当前面临明显的边际效益递减。现有模型已吞噬了互联网上10^13到10^14个标记的公开文本,行业不得不转向昂贵的合成数据与聘请博士专家进行人工标注,但这种打补丁的做法无法解决模型对基础逻辑的缺失。LeCun强调,依赖堆叠参数与算力在两年内造出“数据中心里的爱因斯坦”完全是不切实际的幻想。在商业层面,消费级应用虽可触达数亿用户以平摊推理基建成本,但在企业级部署中,即便是95%准确率的工具也会带来不可承受的5%幻觉风险,导致企业概念验证(POC)项目中仅有10%至20%能真正进入生产环境,重蹈类似当年IBM Watson落地失败的覆辙。 物理常识的缺失与视频生成的伪世界模型 人类与动物能够借助少量先验常识实现零样本问题解决,例如四岁儿童在1.6万清醒小时中通过视觉和触觉接收约10^14字节的多模态输入,九个月大婴儿仅需约10^13字节输入便能掌握重力和动量等直觉物理学,而处理同等数据量(约30万亿标记)的LLM需人类连续阅读40万年却依然缺乏常识。针对利用Sora等视频生成模型构建世界模型的做法,LeCun明确表示反对:文本仅有约10万个离散标记,自回归预测在数学上成立,但物理世界处于连续高维空间,让模型去逐个预测像素不仅在计算上不可行,而且迫使系统在无关的混沌噪点上耗费算力。视频模型表面上连贯的人体动作源自针对高频人类提示的大量微调,一旦遇到异常物理交互(如车辆撞向草垛)便会暴露出缺乏物理因果推理的破绽。 JEPA架构与面向目标规划的全新范式 (49:00) 真实智能必须具备四大支柱:理解物理世界、持久记忆、逻辑推理以及面向目标的行动规划。Meta正在推进的联合嵌入预测架构(JEPA,包括I-JEPA与V-JEPA)放弃了生成式像素预测,转而在抽象特征的潜空间中运作,编码器能够滤除不可预测的环境噪音并保留本质因果不变性。更进一步的“动作条件化JEPA”(Action-Conditioned JEPA)能够接收当前世界状态与预定动作,在抽象表征空间中预测下一步状态。通过在潜空间串联这些推演,AI系统即可模拟未来、检验假说,并搜索能够达成既定目标的最优动作序列,实现真正的规划与推理。LeCun预计,将此类世界模型从实验室验证转化为可扩展的通用架构仍需三到五年时间。 开源科研生态与全球协同创新的优势 (54:33) 针对通用人工智能研发路径,LeCun强调突破依赖于全球科学界持续透明的协作,而非个别封闭团队的单一黑盒。开源生态能动员全球智力,其创新迭代速度天然优于闭源研发;企业在原型设计后为了降低推理成本、保障数据安全与实现本地部署,往往会从专有API转向Llama等开源模型。针对地缘政治层面的封锁论调,LeCun指出科学突破本质上是去中心化的,例如全科学界引用量最高的论文ResNet诞生于微软亚洲研究院,原版LLaMA也是由巴黎FAIR实验室仅12人的团队完成,封闭与单边主义只会阻碍科技的整体演进。 LeCun重申,通向人类水平AI的道路必须建立在非生成式的世界模型与开源生态之上,而非对LLM做盲目的规模扩张。然而,以JEPA为代表的新架构能否在三至五年内顺利解决复杂环境下的长序列动作规划与工程化验证,仍是有待学术界与产业界共同检验的未决课题。

Detailed notes — zh

## Background 该内容由科技播客《Big Technology Podcast》的主持人 Alex Kantrowitz 于 2025 年 3 月 19 日发布在 YouTube 平台。节目邀请了 Meta 首席 AI 科学家、图灵奖得主 Yann LeCun,共同探讨当前生成式 AI 为何在掌握全人类知识的前提下仍无法自主完成科学发明,并深入剖析现有模型的瓶颈、未来世界模型范式以及 DeepSeek 冲击下的开源价值。 ## TL;DR Yann LeCun 直言当前基于自回归与文本概率的大语言模型(LLM)已面临严重边际效应递减,其本质仅是信息检索与文本反刍,无法实现真正的逻辑推理与科学发现。他指出,人类与动物依靠内部抽象心理模型来认知物理世界并进行目标规划,而像素级的视频生成同样是理解物理法则的死胡同。未来的通用智能必须具备物理世界理解、持久记忆、推理与规划四大核心能力,Meta 正押注的 JEPA(联合嵌入预测架构)正是通过在抽象特征空间中预测与搜索,为真正的智能体铺平道路。此外,LeCun 警示了盲目押注 AGI 银弹可能引发的行业泡沫,并结合 ResNet、Llama 和 DeepSeek 的成功,力证硅谷无法垄断技术创新,开源生态将成为全球 AI 演进的绝对主导力量。 ## Atmosphere & style 整场对话节奏紧凑且火花四溅,充满浓厚的学术求真与理性审视氛围。面对行业内部激进的 AGI 宣传和资本狂热,Yann LeCun 展现出典型科学家的冷静、犀利与毫不妥协的直率,频繁用生动的思维实验、即兴数学计算与科技史经典教训无情戳破营销泡沫。Alex Kantrowitz 则扮演了敏锐的追问者角色,不断抛出企业落地痛点、巨额投资风险以及前沿技术案例进行交锋,两人九年交往形成的默契让整场对谈既有深刻的底层技术解构,又充满对全球技术格局的宏大视野。 ## Bulletin - [10:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=640s) 大语言模型已消耗尽全球公网文本(约 10^13 至 10^14 个 token),正在遭遇边际收益递减;仅靠扩大规模无法实现人类水平的 AI。 - [29:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1777s) 真正的下一代智能系统必须具备四大核心能力:理解物理世界、持久记忆、推理与规划能力,大规模实用化预计需 3 到 5 年时间。 - [40:43](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2443s) 微观像素级视频预测是理解物理世界的死胡同;Meta 押注的 JEPA 架构通过在抽象表征空间中预测,能够有效过滤不可预测的微观细节并支持动作规划。 - [56:39](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3399s) DeepSeek 与开源生态证明硅谷并未垄断顶尖 AI 创新,历史上的 ResNet 以及初代 Llama 分别诞生于北京与巴黎的小规模团队。 ## Key takeaways - [00:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=0s) 大语言模型本质上完全基于纯文本概率检索与反刍,其架构缺乏抽象心理模型,结构上无法自主做出颠覆性的科学发现。 - [01:55](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=115s) 人类并不用语言进行底层思考,语言只是沟通输出工具;真正的智能需要基于常识与心理模型提出前所未有的核心问题。 - [05:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=340s) 当前的思维链(Chain of Thought)只是在既有模型上打补丁,并非真正的推理;真正的推理需要在潜在解空间中展开搜索与验证。 - [10:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=640s) 大模型训练面临互联网自然文本耗尽与边际收益递减的瓶颈,依靠合成数据和昂贵专家标注无法解决底层逻辑缺陷。 - [16:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=989s) 宣称在数据中心打造“国家级天才”纯属夸大营销,大模型给人的“博士在侧”感仅仅是庞大记忆与检索带来的幻觉。 - [19:49](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1189s) 科技巨头当前的天文数字资本支出主要用于建设服务数亿至十亿用户的推理基础设施,而非盲目押注训练突破。 - [21:13](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1273s) 企业级生成式 AI 正面临 5% 幻觉与长尾可靠性难题,重现了历史上 IBM Watson 以及 20 世纪 80 年代专家系统泡沫的破灭风险。 - [29:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1777s) 下一代智能系统必须摆脱纯文本输入,补足理解物理世界、持久记忆、推理与规划四大核心能力,大规模落地预计需 3 至 5 年。 - [31:58](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1918s) AGI 不会是一次性降临的突发事件,也不存在所谓“神秘 5 人初创团队掌握银弹”的神话,而是依赖全球科研社区的开放演进。 - [38:04](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2284s) 四岁幼儿清醒时接收的感知数据量(约 10^14 字节)仅相当于 30 分钟 YouTube 视频,但婴儿在 9 个月内便能掌握重力等直觉物理,证实纯文本模型存在信息维度缺失。 - [46:47](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2807s) 高维连续空间中表示所有像素分布在数学上完全不可行,依赖生成式重构或像素级视频模型无法让人工智能真正掌握物理世界规律。 - [48:57](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2937s) JEPA 架构通过放弃像素重建、转向在特征表征空间进行预测,能够规避细节噪声,并在动作条件化下推演达成目标的行动序列以实现真正规划。 - [54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) DeepSeek 的成功印证了开源生态吸纳全球多元智力的力量,在成本、安全性和本地部署上具备长期超越闭源专有模型的优势。 - [56:39](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3399s) 历史表明技术突破具有全球化特征:史上引用最高的深度学习论文 ResNet 诞生于北京,初代 Llama 模型则由巴黎仅 12 人的团队研发完成。 ## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=0s) 生成式 AI 为何无法自主做出科学发现 播客主持人 Alex Kantrowitz 欢迎图灵奖得主、被誉为“AI 教父”的 Meta 首席 AI 科学家 Yann LeCun 做客节目。对话开门见山,Kantrowitz 抛出了播客主持人兼研究者 Dwarkesh Patel 在几个月前提出的一个核心疑问:当前的生成式 AI 几乎已经记住了整个人类知识库,但为何至今未能自主建立任何导致重大科学发现的新连接?反观一个智力尚可的普通人,如果脑中掌握了如此海量的信息,完全能够轻易观察出某些跨领域的关联(例如“A 会引发这种症状,B 也会引发这种症状,或许这能成为某种医疗治愈方案”)。 对于这个质疑,LeCun 的回应干脆利落:“如果是问真正的 AI,是的;但如果是指大语言模型(LLM),答案是否定的。”(“Well, from AI, yes. From large language models, no.”)他指出,公众在探讨人工智能时,很容易将整个 AI 领域等同于聊天机器人。大语言模型本质上完全基于纯文本进行训练,其运作机制是检索、反刍,并生成在统计概率上符合训练语料分布的回答。这种技术极具实用价值且令人惊叹,但其最纯粹的形态在底层结构上根本不具备创造新事物的能力。 - 当前 LLM 依托海量纯文本训练,本质上是在执行概率统计下的内容复述与信息检索。 - 大模型经常产生偏离事实的幻觉(Hallucination),从结构根源上就无法凭借自身纯粹的模型架构发明前所未有的新知识。 --- ### [01:55](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=115s) “数据中心里的爱因斯坦”与真正的思维机制 Kantrowitz 引入了 Hugging Face 联合创始人 Thom Wolf 近期在 LinkedIn 上引发广泛热议的一段观点:要想在数据中心里创造出一个爱因斯坦,我们需要的绝不仅是一个知道所有既有答案的系统,而是一个能够提出前人从未想过、不敢提出的问题,并且敢于在所有教科书、专家和常识都持相反意见时写下“如果大家全搞错了呢?”的系统。Kantrowitz 借此追问:通过训练,大语言模型有可能做到这一点吗? LeCun 斩钉截铁地回答:“不,以当前的形式绝对不行。”他强调,未来任何能够实现这种科学探索的 AI 架构,核心都绝不会是 LLM;LLM 届时充其量只是复杂系统中的一个子模块,用来把系统内部的抽象思想转化为自然语言。LeCun 借用人类神经生物学打了个生动的比方:人类大脑中负责语言表达的区域是微小的布罗卡区(Broca's area),大小仅如拳头一角,那才是人类大脑中的“LLM”;然而人类根本不是用语言进行底层思考的。人类真正的智能发生在大脑更广阔的认知区域,人在说话前大脑中就已经具备了关于现实情境的心理模型(Mental Model)和内部表征,哪怕是不会说话的人同样拥有完整的思维能力。 LeCun 进一步解构了科学研究所需的不同能力层次: 1. **记忆与信息检索**:大语言模型最擅长此类任务,能够调动百年前教科书中写过的方程式与答案。 2. **给定问题的求解**:学生在学校里表现好,能解开考卷上的数学或物理题,即擅长把明确的问题转化为方程并求出答案。 3. **提出正确的核心问题**:这是科研中最困难也是最高阶的技能。提出正确的问题、以崭新的视角重新构建问题框架,与解方程完全属于不同的思维尺度。 ```mermaid flowchart TD accTitle: 科学研究的三层认知能力与当前 LLM 的对应关系 accDescr: 展示人类科研能力从低到高的三层结构,以及大语言模型当前所处的局限位置。 subgraph LLMCapable["当前 LLM 擅长的领域"] A["记忆与检索现有知识<br/>(例如:翻出百年前教科书中的方程)"] end subgraph ProblemSolving["过渡性能力(传统计算与部分算法)"] B["求解给定的已知问题<br/>(例如:按部就班推导数学/物理方程)"] end subgraph TrueDiscovery["人类前沿科研的核心(LLM 完全缺失)"] C["重构问题框架与直觉<br/>(例如:提出前所未有的好问题、挑战既有常识)"] D["内部抽象心理模型<br/>(非语言维度的概念推理与模拟)"] end A -.->|"无法自发跃升至"| C D --> C C --> B B --> A ``` LeCun 指出,大语言模型只能在既有解的范围内做检索,面对全新问题毫无提出新解法的能力,更遑论提出能够指引方向的核心好问题。 --- ### [05:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=340s) 思维链(Chain of Thought)不是真正的推理 针对当前大语言模型通过逐步推理(Step-by-step)演进为“推理模型”(Reasoning Models)的趋势,Kantrowitz 提问:是否可以通过提示词或指令注入,让推理模型主动去质疑既有指令,从而培养这种反常识或“离经叛道”的科学探索能力? LeCun 剖析了当前业界开发推理模型的技术底色。他指出,目前业内普遍的做法只是在现有大模型架构上“修修补补”,而不是彻底改变范式:“大家试图通过在不彻底推翻既有范式的前提下对其进行缝补来解决问题……就像是在 LLM 上面拧上几个螺栓,让它具备某种原始的推理功能。”(“And the way people are approaching the problem at the moment is that they basically are trying to do this by modifying the current paradigm without completely changing it, okay? So can you bolt a couple bolts on top of LLM so that you kind of have some primitive reasoning function?”) 典型手段就是思维链(Chain of Thought):强制模型生成远超回答本身所需的冗余 Token,寄希望于模型在生成这些 Token 的过程中投入更多算力去排查答案。LeCun 承认这在表面上出人意料地管用,但其实际效果极其有限,根本算不上真正的推理。在经典人工智能领域,真正的推理必然涉及**在可能解的空间中进行搜索(Search through a space of potential solutions)**:系统具备明确定义问题是否得到解决的评估机制,并在广袤的解空间中搜寻能满足约束条件的解。 LLM 本身完全缺乏这种内生的搜索机制。为了模拟推理,现有的做法往往是让 LLM 生成大量候选回答序列(Token sequences),再挂接一个外部判别系统从中挑选最佳答案。LeCun 直言,这种方法就像是通过随机敲击符合语法规则的代码指令来写程序,然后逐个运行检查哪个能跑通一样,效率极其低下,根本不是严谨的推理之道。 - **思考空间的不同**:人类和动物的推理发生在抽象的连续空间(Abstract continuous space)和内部心理模型中,而不是在离散的词元空间(Token space)。 - **心智模拟实验**:LeCun 举例,如果让人在脑海中想象一个正方体悬浮在面前,并沿垂直轴旋转 90 度,人能立刻在脑海中直接“看到”旋转后的立方体与原来一模一样。这种空间推演完全脱离了语言,没有生成任何词元,机器至今完全无法复现这种底层的心理模型模拟能力。 - 对话最后,Kantrowitz 提到 DeepSeek 问世时网络上广为流传的一张截图:用户让 DeepSeek 输出关于“人类生存境况(The Human Condition)”的独到见解,模型虽然洋洋洒洒生成了看似极其深刻的剖析,但实质上依然只是 AI 精心编织的词元拼接把戏,而非真正的原创洞见。 ### [10:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=640s) 思维链的本质与大语言模型的边际效应递减 主持人 Alex Kantrowitz 谈到,很多时候观察大语言模型的思维链(Chain of Thought),感觉它只是在复述人类已有的书籍内容,就像是“读了《人类简史》(*Sapiens*)以及其他一些书,然后把它们吐出来作为思维链”。Yann LeCun 对此表示赞同,指出这其中很大程度上只是机械式的“反刍”(regurgitation)。随后主持人将话题引向核心争议:过去只要投入一定量的数据和算力,大模型就能获得可预测的性能提升,但现在训练标准大模型是否已经接近撞墙? Yann LeCun 澄清说,他不确定是否该用“撞墙”(wall)来形容,但这绝对是收益递减(diminishing returns)。他指出,人类实际上已经把互联网上所有可用的自然文本数据消耗殆尽了,现有大语言模型的训练量级已经达到了 $10^{13}$ 到 $10^{14}$(10万亿至100万亿)个 token。尽管部分机构试图通过采购非公开版权数据、生成合成数据(synthetic data)或是高薪雇佣成千上万名博士与大学教授来人工补充专业知识漏洞,但这些系统的根本缺陷在于连最基础的逻辑都无法真正理解。因此,沿着这条技术路线走下去,虽然能取得缓慢进展,但数据生成的成本正在急剧膨胀,带来的回报却微乎其微。 ```mermaid flowchart TD accTitle: LLM scaling dilemma accDescr: 展现大语言模型在数据消耗殆尽与收益递减下面临的困境及新范式诉求。 subgraph LLM_BottleNeck["传统 LLM 的扩张瓶颈"] A["训练数据消耗殆尽<br/>(10^13 ~ 10^14 Tokens 公网数据)"] --> B["边际收益递减<br/>成本激增而效果提升微弱"] C["填补手段<br/>(版权数据 / 合成数据 / 雇佣专家)"] --> B B --> D["核心缺陷<br/>缺乏底层逻辑理解与规划能力"] end subgraph New_Paradigm["急需的新范式"] E["具备搜索与验证机制"] F["面向目标的动作序列规划"] G["自主解决未见新问题的能力"] end D -.->|"驱动转变"| New_Paradigm ``` --- ### [12:43](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=763s) 真正的智能体与人类的系统一/系统二思维 面对现有架构的局限,Yann LeCun 直言:“我们需要一种新范式。”他强调,核心在于构建能够自主搜索可行解、检验解的正确性,并能规划一系列行动以达成特定目标的架构,而这正是让真正的智能体(Agentic system)运转所不可或缺的底层逻辑。然而现实情况是,“每个人都在谈论智能体系统,但除了反刍系统已经训练过的方案之外,没有人知道该怎么构建它们”。 在探讨如何面对全新的、从未训练过的问题时,Yann LeCun 借用了认知科学家丹尼尔·卡尼曼(Daniel Kahneman)关于“系统一”(直觉、下意识)与“系统二”(深思熟虑、理性推理)的理论: - **人类的学习模式**:人类学习驾驶只需二三十个小时。最开始上路时,全神贯注调用“系统二”,在脑海中预演各种灾难场景;经过数十小时练习后,驾驶便转化成了不用过脑子的潜意识习惯,变成了“系统一”,此时人们甚至可以一边开车一边自如交谈。 - **车轮战国际象棋的启示**:LeCun 回忆起曾在一场研讨会上与一位国际象棋特级大师同台,这位大师同时与大约 50 个人进行车轮战。大师走到 LeCun 的棋盘前,看到他走了一步甚至感到莫名其妙,随即几乎不假思索地落子反击,十几个回合就把 LeCun 淘汰出局。LeCun 自嘲棋艺糟糕,并指出:“我并不是一个足够有挑战性的对手,以至于他根本不需要调用他的系统二,他的系统一就足以击败我。” - **现存 AI 的致命缺陷**:熟练的任务可以通过反复训练进入潜意识,但人类与动物最根本的能力在于——面对前所未见的新情况时,仅凭对现实世界运转方式的基础常识(common knowledge),就能通过推理规划出达成目标的行动序列,这正是当前 AI 体系彻底缺失的能力。 --- ### [16:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=989s) 泡沫质疑与“身边坐着一位博士”的幻觉 主持人提出质疑:如果大语言模型已经进入收益递减阶段,而新范式尚需数年研究且前路未卜,那么近来涌入该领域的天文数字资金是否面临巨大风险?例如 OpenAI 融得 66 亿美元,Anthropic 在去年获得 40 亿美元后近期又获得 35 亿美元,埃隆·马斯克(Elon Musk)也投入巨资打造 Grok。这些以大模型为先的公司若是将资金砸向收益递减的旧方向,是否会导致行业危机? Yann LeCun 对此作出了极为犀利的论断,正面反驳了行业内某些同行的激进宣传: > “首先可以明确的是,我们不可能仅仅通过扩大 LLM 的规模来达到人类水平的 AI,这绝不可能发生。无论你从我那些更大胆的同行那里听到了什么,它都不会在未来两年内发生,无论如何都绝无可能(there's absolutely no way in hell)……所谓我们在数据中心里将拥有‘一个国家级别的天才’(a country of geniuses in the data center),这纯粹是胡扯。” 对于当前 AI 能够达到的上限,LeCun 做出了具象化的剖析: - 随着海量数据的填充,模型能够回答常人提出的绝大多数问题,这会让人产生一种错觉,“感觉就像你身边坐着一位博士(PhD)”。 - 但实质上,用户身边坐着的绝非真正的博士,而只是“一个拥有庞大记忆与检索能力的系统”,根本无法针对全新问题发明独创性的解决方案,而创造性解决未知问题才是博士学位的本质。 --- ### [19:49](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1189s) 科技巨头的万亿基建算盘:为推理而非幻觉买单 对于资本支出的去向,Yann LeCun 为巨额投资进行了合理的商业解释。他指出,当前的投资并非为了应对明天,而是布局未来数年,且绝大部分资本支出(以 Meta、微软、谷歌以及亚马逊等巨头为例)实际上是在建设**推理基础设施(inference infrastructure)**,而非漫无目的的模型训练。 - **Meta 的核心目标**:计划在年底前让 Meta AI 的常规用户规模达到 10 亿人,覆盖智能眼镜(smart glasses)、独立应用程序等多种终端。 - **算力刚性需求**:为 10 亿用户提供日常交互服务需要吞吐量极其庞大的运算资源,因此必须提前数月甚至数年建设并扩展数据中心。 - **商业落地的现实性**:即使底层技术范式在未来三年内没有任何革命性突破,这 10 亿人规模的市场也切实存在,建成的庞大算力基础设施依然能够被充分调用并产生运营价值,因而这类投资具有明确的实用考量。 ### [21:13](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1273s) 消费级爆款与企业级落地的“最后一公里”困境 Alex Kantrowitz 指出,搭建数据中心和基础设施周期极为漫长,科技巨头只要手头有充足的现金流就必须提前布局,承担不起落后的风险。然而,现有技术依然存在深层缺陷。在消费端,Meta 押注数十亿普通手机用户,OpenAI 的 ChatGPT 拥有约 4 亿用户,而 Meta AI 更是斩获超过 6 亿用户,向 10 亿用户迈进看似顺理成章(虽然人均使用时长和粘性尚不如 ChatGPT)。然而,海量投资的真正逻辑支撑是“企业级价值”,但目前在企业落地中却撞了墙。Alex 援引科技分析师 Benedict Evans 的观点举例:Deep Research 类产品或许能做到 95% 的准确率,但剩下的 5% 仍会产生幻觉;如果一份 100 页的研究报告里有 5% 的致命错误,而读者根本不知道哪 5 页是错的,这在严肃商业中就是不可接受的。因此,绝大多数企业即便迫切希望引入生成式 AI,往往也只有 10% 到 20% 的概念验证(PoC)能真正上线投产,其余不是太昂贵就是可靠性不足。 Yann LeCun 对此回应,从令人惊叹的 Demo 到构建真正可靠的工业级系统,这种落地断层绝非 AI 独有,而是计算技术发展史上的老问题。他打比方道,就像 10 年前自动驾驶的演示视频就已极其震撼,但直到今天人类依旧没有实现真正的 L5 级全自动驾驶。核心难点永远在于决定系统能否实用的最后几个百分点的可靠性,以及如何与现有生产流无缝集成。 - **IBM Watson 的前车之鉴**:LeCun 回忆起 IBM Watson 当年的惨痛教训。IBM 曾高调宣称 Watson 将通过学习医学知识彻底颠覆医疗行业、进驻全球每家医院,并带来巨额商业回报。然而,系统在面对实际临床医疗的高可靠性要求与劳动力群体的保守惯性时彻底崩盘,最终落得项目惨败、拆分变卖资产的结局,不仅耗费巨资,甚至让时任管理层付出了沉重代价。 ### [25:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1537s) 历史的循环:专家系统的兴衰与潜在的“AI 寒冬” 面对当前企业级落地的迟滞,LeCun 梳理了 20 世纪 80 年代初的“专家系统”(Expert Systems)浪潮。在那段狂热期,业界普遍认为未来最炙手可热的岗位是“知识工程师”(Knowledge Engineer),其职责是坐在行业专家身旁,将专家的经验抽取为规则与事实,输入推理引擎去推导结论。日本政府甚至为此发起了轰动一时的“第五代计算机”国家计划,试图从硬件层面直接适配这套逻辑。然而到了 90 年代中期,这场热潮彻底破灭。事实证明,专家系统仅在极少数能被规整归纳且具备经济可行性的狭窄领域奏效,根本没有带来许诺中的全社会与全行业变革。 Alex Kantrowitz 随之提出犀利的质疑:当年 LeCun、Yoshua Bengio 和 Geoffrey Hinton 坚持神经网络路线时曾连学术会议都坐不上前排,直到算力跟上才迎来爆发;如今大批资金是奔着“神级能力”(God-level capabilities)砸进去的,一旦收益递减遭遇预期时间线脱节(Timeline mismatch),叠加股市波动,行业是否会迎来又一次严重的“AI 寒冬”和舆论反弹? LeCun 承认时间线错配带来的反噬风险,但他强调大语言模型(LLM)并非毫无用处,至少在企业内部知识检索上已经发挥了实质作用(例如 Meta 内部用来检索海量文档的 AI 工具“Metamate”就非常实用)。但对于盲目的资本泡沫,LeCun 直言不讳地警告道: > “如果你认为只要靠训练更多数据和扩大 LLM 规模就能达到人类水平的 AI,那你是在犯错。” —— Yann LeCun > “如果你是一名投资人,投资了一家向你宣称‘只要用更多数据外加一点小技巧就能达到人类水平和博士水平 AI’的公司,我不知道你会不会输得精光,但这大概率不是个好主意。” —— Yann LeCun ### [29:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1777s) 迈向物理世界的四项真正智能与时间表 LeCun 指出,要打破 LLM 的固有瓶颈,就必须转向全新的架构,让 AI 具备自然界中任何有智能的动物乃至人类幼崽都拥有的基础能力。现有的系统严重依赖人类产出的二手文字符号,缺乏对现实世界的物理交互与常识理解。真正的下一代智能系统必须补足四大核心特征: ```mermaid flowchart TD accTitle: 下一代智能系统的四大核心特征 accDescr: 该图展示了 Yann LeCun 提出的真正智能系统所需具备的四个核心能力:物理世界理解、持久记忆、推理能力和规划能力。 subgraph CoreCapabilities["真正的智能系统必须具备的四大核心能力"] A["理解物理世界<br/>(Understanding the Physical World)"] B["具备持久记忆<br/>(Persistent Memory)"] C["具备推理能力<br/>(Reasoning)"] D["具备行动规划能力<br/>(Planning)"] end A --- B B --- C C --- D ``` 针对这一路径,LeCun 和他的团队(以及 DeepMind 和多所高校的部分学者)多年来一直在探索世界模型(World Models),试图让系统直接通过视频等自然传感器数据理解物理法则,利用内部的心理模型(Mental models)来规划一系列行动以达成目标。关于这些前沿架构何时能走出实验室、从精巧的学术论文演变为大规模实用的工业系统,并在未受专门训练的情况下解决全新问题,LeCun 给出了明确的预期界限:这不可能在未来 3 年内发生,但很可能会在 3 到 5 年的区间内迎来破局。 - **四大必备特征**:理解物理世界(Understanding the physical world)、持久记忆(Persistent memory)、推理(Reasoning)以及规划能力(Planning)。 - **学习范式转移**:从仅依赖人类生产的文本数据(Text),转向通过视频等高维自然信号获取物理常识。 - **产业化时间线预判**:具备泛化规划能力的大规模世界模型架构,无法在 3 年内实现,更有可能发生在 3 至 5 年之间。 ### [31:58](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1918s) AGI 不是一次性事件,没有所谓“秘密银弹” Yann LeCun 指出,当前的投资激增大致对应着过去几年的技术发展轨迹,但人们对实现通用人工智能(AGI)的理解存在根本误区。通往 AGI 不可能依靠某一家公司或某一个团队突然发明出某种能解决所有问题的“秘密银弹(Magic Bullet)”。相反,这将是一个需要大量不同想法、海量工作以及依托核心科学原则不断试错的过程。部分研究方向最终会被证明是死胡同,因此绝对不会出现“某一天之前没有 AGI,而某一天之后突然拥有了 AGI”的戏剧性拐点。 ```mermaid flowchart TD accTitle: AGI 发展演进路径 accDescr: 对比错误认知的 AGI 单点突破与现实中的全球学术协作演化路径。 subgraph 错误幻觉["投资人/公众的错误认知"] A["神秘5人初创公司"] -->|"宣称掌握秘密"| B["投入 50 亿美元"] B -->|"单点突破"| C["突然降临的 AGI 事件"] end subgraph 现实路径["真实的科研演进"] D["全球研究社区广泛协作"] -->|"开源与概念共享"| E["持续概念创新与规模化验证"] E -->|"淘汰死胡同方向"| F["渐进式实现高级机器智能"] end ``` LeCun 强调,AI 的进步是由全球研究社区不断提出连续的概念性想法,并随着时间推移将其放大、规模化从而逐步提升性能而来的。在这一过程中,乐于分享研究成果的人群往往比闭门造车的人走得更快。针对当前的投资狂热,LeCun 直言:“如果你认为某处有一家只有五个人的初创公司已经发现了 AGI 的秘密,而你应该向他们投资 50 亿美元,那你正在犯一个巨大的错误。”(“...if you think that there is some startup somewhere with five people who has discovered the secret of AGI and you should invest five billion in them, you're making a huge mistake.”) - AGI 的诞生不会是一次性的突发事件,而是由全球科研社区共同推进的连续演进。 - 盲目相信小型初创公司掌握 AGI 独家秘密并投入数十亿美元是巨大的资本误判。 - 开放共享成果的研究者在推动技术演进的速度上显著快于封闭研发的团队。 --- ### [33:19](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1999s) 纸张物理实验与长尾问题的后训练困境 播客主持人 Alex Kantrowitz 提到,这是他第三次邀请这位图灵奖得主兼 Meta 首席 AI 科学家做客节目,并回忆了此前在节目中进行过的一个经典测试:当时 LeCun 让 Kantrowitz 询问 ChatGPT:“如果我双手水平拿着一张纸,然后松开左手,会发生什么?”在当年的测试中,ChatGPT 信誓旦旦地胡说八道,声称根据物理规律,纸张会向左手方向飘去;当时 Kantrowitz 读完甚至觉得听起来很有道理,LeCun 当场戳穿系统只是在产生幻觉。时隔两年,Kantrowitz 再次测试了相同的问题,如今的 ChatGPT 能够正确解释:由于重力作用,纸张左侧会下落,而右手持握的部分保持不动,从而形成以右手为支点的旋转效果。 针对大模型看似“学会了物理”的表象,LeCun 冷静地指出这并不能说明模型真正理解了物理世界。极有可能的情况是,OpenAI 雇佣的数据标注人员注意到了这个问题,并将标准答案写进数据集中对系统进行了微调。LeCun 解释道,这就是大语言模型“后训练(Post-training)”变得极其昂贵的原因所在。现实世界中存在着几乎无限维度的类似常识问题,试图通过暴力覆盖去解决长尾效应是不可能的。模型无论怎么补课,无法回答的长尾物理问题数量永远远多于其能够回答的问题。 - 模型的表面进步往往源于针对特定失败案例的数据标注补丁与有监督微调,而非自发理解。 - 面对无限的现实物理交互问题,大语言模型的后训练方法面临巨大的长尾覆盖瓶颈。 - 无论训练集如何扩展,穷尽现实世界所有可能发生的物理交互提问在数学上是不可能的。 --- ### [36:28](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2188s) 从 Sora 生成视频到真实物理常识的差距 Alex Kantrowitz 追问,既然语言模型难以单靠文本掌握现实动态,那么多模态的视频生成模型(例如 OpenAI 的 Sora)是否展现了真正的物理理解。在过去的讨论中,LeCun 曾提出让 AI 预测“将铅笔竖直放在桌上松手会发生什么”极其困难,因为可能出现的排列组合过于繁琐;然而现在,只要向 Sora 输入指令生成“一个坐在椅子上踢腿的人”,生成的视频中人物双腿并不会脱臼,关节活动自如,也不会长出第三条腿。Kantrowitz 质疑这是否标志着大模型已经具备了物理层面的质变。 LeCun 断然否定了这一看法。他指出,当前的视频生成系统依然频频产生违背物理定律的荒谬画面,例如倒红酒时红酒突然悬浮在空中、横向飞走或直接原地消失。面对特定场景,工程师当然可以通过采集更多同类视频数据来强行拟合,但这绝非理解底层现实,而是在“用越来越庞大的数据量来弥补对世界缺乏理解的缺陷”(“...compensating the lack of understanding by increasingly large amounts of data...”)。 - 尽管视频生成工具在部分常规动作上表现自然,但在复杂的流体、接触力学中仍频繁暴露荒谬的物理缺陷。 - 依赖海量特定视频片段来修补特定生成缺陷,只是表象拟合,并未触及物理常识的核心。 --- ### [38:04](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2284s) 视觉输入的数据吞吐量与婴儿的物理直觉 为了阐明为什么单纯依靠文本无法逼近人类智力,LeCun 现场进行了数据量级的直观推算。一个基于约 30 万亿 Token(3×10¹³ Token)训练的主流大语言模型,按每个 Token 约等于 3 字节计算,总数据量约为 10¹⁴ 字节;普通人类即便每天连续阅读 12 小时,读完这些文本也需要大约 40 万年。与之相对,一个四岁幼儿清醒的时间大约是 16,000 小时(约 5.76×10⁷ 秒)。人类视网膜的两条视神经每条每秒传输约 1MB 数据,双眼合计每秒 2MB。在四年时间内,视神经向大脑视觉皮层输入的数据量同样达到了约 10¹⁴ 字节,而这 16,000 小时的视频流仅仅相当于 YouTube 每 30 分钟收到的视频上传量。 ```mermaid flowchart LR accTitle: 训练数据吞吐量对比:LLM vs 四岁儿童 accDescr: 对比主流大语言模型的文本输入量与四岁幼儿在清醒状态下的视神经数据吞吐量。 subgraph LLM["前沿大语言模型"] A1["30 万亿 Tokens"] --> A2["约 10^14 字节"] A2 --> A3["相当于人类阅读 400,000 年"] end subgraph Child["四岁幼儿感知"] B1["16,000 清醒小时"] --> B2["视神经吞吐: 2 MB/s"] B2 --> B3["约 10^14 字节"] B3 --> B4["仅相当于 YouTube 30分钟视频上传量"] end ``` LeCun 进一步指出,在生命的最初 9 个月里,婴儿接收的数据量仅约为 10¹³ 字节,却在这个阶段完全掌握了基础的“直觉物理(Intuitive Physics)”——包括动量守恒、重力感知、客体永久性(物体被遮挡后依然存在、不会凭空消失)等。这充分表明,人类水平的认知必须建立在感知与物理常识之上,纯文本绝非足够丰富的信息源。机器若想实现真正的智能,就必须复现婴儿这种理解物理可能与不可能、预测行动后果并规划行动路径的能力,即建立真正的“世界模型(World Model)”。 - 主流大模型训练数据量(约 10¹⁴ 字节文本)需要人类阅读 40 万年,但仍无法建立物理直觉。 - 四岁幼儿仅通过约 16,000 小时的感知输入(相当于 30 分钟 YouTube 上传体量)就获得了等量的数据级。 - 婴儿在出生 9 个月内依靠极其有限的数据掌握动量守恒、客体永久性等直觉物理,证实文本模型存在天然信息缺陷。 --- ### [40:43](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2443s) 像素级生成是死胡同,理解需要抽象表征 面对利用更强大的视频生成模型来构建世界模型的行业趋势,LeCun 给出了极其坚决的否定回答:“理解世界的问题并不能通过在像素级别生成视频的方案来解决,绝对不行。”(“...the problem of understanding the world does not go through the solution to generating video at the pixel level... Absolutely no.”) LeCun 以打翻一杯水为例说明:如果一个人在桌前不慎碰洒了水杯,没有任何人类的大脑能够精准预测出每一滴水在桌面上流动的微观路径、形成的精确形状或是发出的具体声响;但在更高层级的抽象维度上,人类可以毫不费力地预测出“水会洒出来”、“手机可能会被泡湿”。试图在微观像素级别精确预测一切,不仅在计算上不可能,在认知上也是毫无必要的冗余。智能系统若想真正理解世界如何运转,关键在于学会世界的“抽象表征(Abstract Representation)”,并在表征空间中进行因果预测与行动规划。因此,真正具备世界理解与推理能力的架构,绝不可能是基于像素预测的生成式(Generative)模型。随后,Alex Kantrowitz 准备向 LeCun 展示一段自己生成的人物踢腿视频 demo,以进一步展开具体探讨。 - 在底层像素层面精确预测未来在物理上是不可预测的,也是对计算资源的无效浪费。 - 人类的核心智能依赖于高层级的抽象预测(例如预知水会洒、物品会受损),而非微观还原。 - 真正的世界模型架构必须基于抽象状态表征进行预测,因而未来的核心智能架构绝不会是像素生成式模型。 ### [42:29](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2549s) 视频生成的物理荒谬与自监督学习的本质 Alex Kantrowitz 分享了一个自己测试视频生成模型的生动案例:他曾生成过一个人坐在椅子上踢腿的视频,双腿完好地连在身体上,他原本以为这项技术取得了真正突破;随后他尝试输入提示词“让一辆汽车撞进干草垛”,结果画面中出现两个草垛,而第三个草垛竟然从一辆静止汽车的引擎盖里凭空冒了出来。Kantrowitz 调侃道:“这车倒挺好看的,但我对自己说:好吧,Yann 又赢了一局。”Yann LeCun 对此解释说,这些系统之所以能在人类动作上表现尚可,是因为训练数据中充斥着海量人类活动的样本(因为绝大多数用户都在请求生成人类视频),但一旦遇到训练者未曾预料到的罕见情境,系统就会彻底穿帮。 ```mermaid flowchart LR accTitle: 自监督学习重建范式 accDescr: 展示自监督学习通过破坏输入并使用神经网络还原真实输入的过程。 A["原始输入 (文本/图像/视频)"] --> B["人为破坏 / 掩码 (Masking)"] B --> C["大型神经网络 (如 MAE / 自回归 LLM)"] C --> D["尝试重建原始完整像素或词元"] ``` 随后讨论转向自监督学习(Self-Supervised Learning, SSL)。LeCun 指出,过去几年 AI 特别是自然语言处理(NLP 聊天机器人)以及部分计算机视觉领域的成功,完全建立在自监督学习之上: - 自监督学习的核心范式是:获取一段输入(图像、视频或文本),对其进行某种形式的“破坏”(corruption),然后训练一个大型神经网络去重建、去畸变或预测因某种动作导致的变换形态。 - 在文本领域,可以通过扣掉几个词让神经网络填空;在图像和视频领域,则是抹去部分区域或片段,让系统去预测缺失内容。 - 大语言模型(LLM)属于自监督学习的一种特例(因果架构 / Causal Architecture),它无需显式破坏文本,而是在网络架构中硬编码了限制,使其只能看到当前词元左侧的上下文(历史),进而预测下一个词元。这种自回归预测(Autoregressive Prediction)将预测出的词再送入输入端预测下一个词,是经典的老技术。 - 自监督学习不需要人工标注,其唯一目的就是捕捉数据内部的固有结构。 Yann LeCun 直言:“这些系统之所以对人类动作有效,是因为使用了海量的人类数据进行微调,但对训练该系统的人未曾预料到的情境则完全失效。”(“That's why it works for humans but not for a situation that the the people training that system had not anticipated.”) --- ### [46:47](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2807s) 生成式自监督在视频领域受阻与高维数学困境 虽然自监督重建在文本上大获成功,并在图像领域产生过像 Meta FAIR 的掩码自编码器(Masked Autoencoder, MAE)这样的项目,但将其推广到视频预测时却遭遇了根本性瓶颈。LeCun 提到自己在这项研究上已经摸索了近二十年:给模型输入一段视频片段,试图让它预测下一帧或补全缺失像素,但效果始终不尽人意。 这种方法在文本中行得通、在视频中却碰壁的数学根源在于: - **离散字典 vs 高维连续空间**:在文本中,系统无法精准确定下一个词是什么,但词表字典总共只有大约 10 万个离散词元(Tokens),模型只需输出一个包含 10 万个非负且和为 1 的概率分布向量即可。 - **高维连续分布不可行性**:要在图像的缺失部分或视频的未来帧中表示所有可能像素组合的概率分布,数学上是完全不可行(intractable)的。学术界至今根本不知道如何在有用的维度上表达高维连续空间中的概率分布。 - **生成式物理理解的死胡同**:因为无法对真实世界未来的所有连续可能做概率分布建模,依赖像素级重构的生成式模型(Generative Models)无法让人工智能真正理解现实世界的运行物理规律。 Yann LeCun 明确断言:“事实上,在数学上表示高维连续空间中的概率分布是完全不可行的,我们根本不知道该如何以一种有效的方式去做到这一点。”(“In fact, it's mathematically intractable to represent distributions in high dimensional continuous spaces, we don't know how to do this properly in fact.”) --- ### [48:57](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2937s) JEPA 范式:放弃像素重建,转向抽象表征预测 为了摆脱生成式模型的死胡同,Yann LeCun 与 Meta 团队提出了非生成式架构方案——联合嵌入预测架构(Joint Embedding Predictive Architecture, 简称 JEPA),包括针对图像的 I-JEPA、针对视频的 V-JEPA 以及针对文本的变体。JEPA 彻底摒弃了在像素层面还原图像或视频的做法,转而通过在特征表征空间(Representation Space)中进行预测来理解世界。 ```mermaid flowchart TD accTitle: JEPA 架构运作流程 accDescr: 展示原始样本与受损样本分别经过编码器映射为抽象表征,再由预测器在特征空间进行对齐。 subgraph 编码阶段 O["完整真实输入 (视频/图像)"] --> E1["编码器 Encoder"] C["受损/掩码输入 (Masked Input)"] --> E2["相同编码器 Encoder"] end E1 --> R1["完整抽象表征 (Ground Truth Representation)"] E2 --> R2["不完整抽象表征"] subgraph 预测与评估阶段 R2 --> P["预测器 Predictor"] P --> R3["预测的抽象表征"] R3 <-->|"特征对齐 / 最小化误差"| R1 end ``` JEPA 架构的具体运行机制与优势包括: - **双编码器与特征预测**:分别将完整输入与被遮蔽的受损输入送入两个相同的神经网络编码器,提取出高维特征表征;随后训练一个“预测器”(Predictor),根据受损输入的表征去预测完整输入的表征。 - **摒弃无效细节**:系统不还原像素,只预测特征层。这使得模型能够自动过滤掉无关紧要、无法精准预测的微观细节。例如一根竖立在桌面上的笔被松开后,没有人能精准预测它会倒向哪个具体角度;生成式模型会因无法生成确切像素而模糊或崩溃,但 JEPA 可以在抽象层级上准确预测“这支笔将会倒下”。 - **训练难点与实现流派**:JEPA 训练的最大难度在于防止表征塌缩(Representation Collapse),必须确保提取的表征尽可能多地包含输入的有效信息。目前 Meta 团队探索了多种训练路径,包括 DINO、VICReg(方差-不变性-协方差正则化)以及基于蒸馏机制的 I-JEPA。 - **违背物理规律测试(常识推理)**:经过海量自然视频训练后的 V-JEPA 展现出了对世界物理常识的理解。当向它输入游戏引擎合成的“不可能物理场景”(如滚动的球滚入挡板后、挡板落下时球凭空消失,或者物体突然改变形状)时,系统会计算预测误差;在物理异常发生的一瞬间,系统的预测误差会出现剧烈峰值,这证明它在抽象表征层级已经建立起了对客观现实一致性的物理预期。 Yann LeCun 总结其核心逻辑:“它并不是生成式的,因为系统并不试图重新生成输入的某一部分,而是试图生成输入的抽象表征,这使它能够忽略所有根本不可预测的细节。”(“It's not generative because the system is not trying to regenerate the part of the input, it's trying to generate a representation, an abstract representation of the input, and what that allows it to do is to ignore all the details that are really not predictable.”) ### [53:06](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3186s) JEPA 的物理常识与基于动作条件的前向预测 Yann LeCun 解释了如何通过预测误差来判断系统是否理解了物理世界的规律。当模型在仅包含符合物理规律的自然视频上进行训练后,一旦画面中出现违背物理常识的不可能事件,系统的预测误差就会“直接爆表”(goes through the roof)。这成为了判断模型是否内化了物理世界可行性规律的关键线索,也是系统习得某种常识的初步迹象。 Meta 团队在此基础上开发了动作条件化(Action-conditioned)版本的架构。在这一设定中,模型接收时刻 $t$ 的世界状态(例如一段视频剪辑或单张图像),以及在此刻执行的操作(如机械臂的移动),进而观察该动作所引发的后续状态。通过这种训练,模型能够在高度抽象的表征空间内,依据当前状态与给定动作直接预测出时刻 $t+1$ 的世界状态。 ```mermaid flowchart LR accTitle: Action-Conditioned World Model accDescr: Diagram showing how current state and action are mapped into an abstract space to predict future state and plan actions toward a goal. subgraph Input ["输入层"] S_t["时刻 t 的世界状态<br/>(图像 / 视频片段)"] A_t["执行动作<br/>(例如机械臂位移)"] end subgraph Model ["抽象表征与预测"] JEPA["JEPA 世界模型<br/>(抽象特征空间)"] S_next["预测时刻 t+1 的状态"] end subgraph Planning ["规划与推理"] Goal["目标状态<br/>(期望的世界样貌)"] Search["序列搜索与规划<br/>(Sequence Search)"] end S_t --> JEPA A_t --> JEPA JEPA --> S_next Goal --> Search S_next -.->|"评估与匹配"| Search ``` 这种机制赋予了系统真正的推理与规划潜力。系统不再只是被动响应,而是可以在脑海中预演一系列连续动作所产生的后果。如果给它设定一个目标,指示“希望最终世界呈现某种特定形态”,模型便能通过在动作序列空间中展开搜索,推演并找出一条能切实达成该目标的路径。LeCun 强调,这才是真正意义上的规划与推理。 - 预测误差剧增是检测系统是否识别出“物理不可行事件”的核心信号。 - 模型在抽象特征空间而非像素空间中预测下一时刻的状态,从而规避了生成无关像素细节的计算浪费。 - Yann LeCun 强调:“如果赋予它一个目标……它实际上能够通过搜索找到一串能够产生该结果的动作序列,那就是规划,那就是推理,那是真正的推理与真正的规划。”(“if you give it a goal saying like I want the world to look like this at the end can you figure out a sequence of actions to get me to that point it can actually figure out by search for a sequence of actions that will actually produce that result that's planning that's reasoning that's actual reasoning and actual planning”) ### [54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) DeepSeek 的冲击与开源生态的绝对优势 节目进入尾声,主持人 Alex Kantrowitz 提出时间已严重超时,Meta 公关团队正在催促结束,但他仍要求 LeCun 用 60 秒回答对 DeepSeek 的看法以及“开源是否已经超越了闭源专有模型”。LeCun 谨慎回应称,“超越”(overtaken)这个词或许言过其实,但开源生态的发展速度必然更快。尽管闭源公司能够随时吸纳开源界的成果,但任何单一公司无论规模多大,都不可能垄断所有好点子。 开源的魔力在于能汇聚全球各地的智力资源。DeepSeek 的成功充分证明,组建一支小规模团队,给予充分的自由度和极少的条框限制,专注于下一代 LLM 的架构改进,就能提出别人未曾想到的创新方法;一旦这些成果向全球公开,全人类的技术水位就会随之整体上升。 - 开源模型不仅技术迭代更快,且拥有显著的部署优势:成本更低、安全性更高、可控性更强,并支持本地私有化部署(On-premise)。 - 业界的实际使用习惯正在分化:许多合作伙伴和客户在原型开发阶段可能会调用闭源专有 API,但一旦进入实际生产环境部署,往往会切换到 Llama 或其他开源引擎以降低成本并确保可控性。 - Yann LeCun 指出:“没有人在好点子上拥有垄断权,因此开源世界的奇迹般效率在于它能够从全球招募人才。”(“nobody has a monopoly and good ideas and so the magic efficiency of the open source world is is that it recruits talents from all over the world”) ### [56:39](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3399s) 硅谷没有好点子的垄断权:从 ResNet 到 Llama 的全球创新 针对此前部分人担忧“开源会帮助中国等竞争对手”的地缘政治论调,LeCun 认为 DeepSeek 的事实彻底反驳了这种假设——中国科研人员完全有能力独立产出顶尖的原创想法,根本不需要依靠外界的技术施舍。LeCun 举出科学史上的重磅案例:整个科学界被引用次数最多的单篇论文正是 2015 年诞生于北京的深度学习经典之作——由微软亚洲研究院(MSRA)何恺明(Kaiming He)等人发表的 ResNet(残差网络)。 ResNet 的核心机制在于让深度网络的每一层默认学习恒等映射(Identity function),即直接将输入复制到输出,网络只需学习对恒等状态的残差偏离,这一突破使得训练数十层甚至上百层的极深神经网络成为可能。LeCun 回忆道,在这篇划时代论文发表后不久,他便将何恺明招募至 FAIR(Meta 基础人工智能研究院)加利福尼亚团队;何恺明在 FAIR 工作了约八年,如今已前往 MIT 担任教授。 创新绝非硅谷的专利。不仅 ResNet 诞生于北京,Meta 自身的开源旗舰模型 Llama 最初也并非诞生于硅谷,而是由巴黎 FAIR 实验室一支仅有 12 人的精悍小团队研发出来的。在节目的最后,Kantrowitz 感谢 LeCun 多年来的分享,回顾了两人从九年前便开始的多次对谈,称赞 LeCun 始终能够穿透外界的营销炒作与浮夸泡沫,直击技术本质。 | 创新成果 / 项目 | 诞生地点与团队 | 关键架构特征与行业意义 | |:--- |:--- |:--- | | **ResNet** (残差网络) | 微软亚洲研究院 (北京),第一作者何恺明 | 默认计算恒等映射,仅学习对恒等态的偏离;解决了深层梯度问题,支持上百层网络训练,成为全科学领域引用最高的论文。 | | **Llama** (初代模型) | FAIR 巴黎实验室,12人小团队 | 证实极小规模的精简团队也能做出顶级基础模型,并奠定了开源大模型生态的基石。 | | **DeepSeek** | 中国本土团队 | 证明在较少约束的灵活架构下能够独立实现 LLM 底层优化与算法创新。 | - Yann LeCun 总结创新的全球化本质:“你必须利用全世界的想法多样性、背景多样性以及充沛的创造力,唯有如此才能让科学和技术快速进步,而这一切正是由开源所赋能的。”(“you have to take advantage of the diversity of ideas backgrounds creative juices of the entire world if you want science and technology to progress fast and that's enabled by by open source”) ## Notable quotes > [25:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1537s) 如果你认为只要靠训练更多数据和扩大 LLM 规模就能达到人类水平的 AI,那你是在犯错。 — Yann LeCun > [40:43](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=2443s) 理解世界的问题并不能通过在像素级别生成视频的方案来解决,绝对不行。 — Yann LeCun > [12:43](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=763s) 每个人都在谈论智能体系统,但除了反刍系统已经训练过的方案之外,没有人知道该怎么构建它们。 — Yann LeCun > [54:33](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=3273s) 没有人在好点子上拥有垄断权,因此开源世界的奇迹般效率在于它能够从全球招募人才。 — Yann LeCun > [05:40](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=340s) 大家试图通过在不彻底推翻既有范式的前提下对其进行缝补来解决问题……就像是在 LLM 上面拧上几个螺栓,让它具备某种原始的推理功能。 — Yann LeCun > [25:37](https://www.youtube.com/watch?v=qvNCVYkHKfg&t=1537s) 如果你是一名投资人,投资了一家向你宣称‘只要用更多数据外加一点小技巧就能达到人类水平和博士水平 AI’的公司,我不知道你会不会输得精光,但这大概率不是个好主意。 — Yann LeCun ## Mentioned Yann LeCun, Alex Kantrowitz, Dwarkesh Patel, Thom Wolf, Hugging Face, DeepSeek, Daniel Kahneman, OpenAI, ChatGPT, Anthropic, Elon Musk, Grok, Meta, Meta AI, Microsoft, Google, Amazon, Benedict Evans, IBM Watson, Yoshua Bengio, Geoffrey Hinton, DeepMind, Sora, YouTube, FAIR, MAE, JEPA, I-JEPA, V-JEPA, DINO, VICReg, 何恺明, 微软亚洲研究院, ResNet, Llama, MIT ## Video description Yann LeCun is the chief AI scientist at Meta. He joins Big Technology Podcast to discuss the strengths and limitations of current AI models, weighing in on why they've been unable to invent new things despite possessing almost all the world's written knowledge. LeCun digs deep into AI science, explaining why AI systems must build an abstract knowledge of the way the world operates to truly advance. We also cover whether AI research will hit a wall, whether investors in AI will be disappointed, and the value of open source after DeepSeek. Tune in for a fascinating conversation with one of the world's leading AI pioneers. Chapters: 00:00 Introduction to Jan LeCun and AI's limitations 01:12 Why LLMs can't make scientific discoveries 05:40 Reasoning in AI systems: limitations of chain of thought 10:13 LLMs approaching diminishing returns and the need for a new paradigm 16:29 "A PhD next to you" vs. actual intelligent systems 21:36 Consumer AI adoption vs. enterprise implementation challenges 25:37 Historical parallels: expert systems and the risk of another AI winter 29:37 Four critical capabilities AI needs for true understanding 33:19 Testing AI's physics understanding with the paper test 37:24 Why video generation systems don't equal real comprehension 43:33 Self-supervised learning and its limitations for understanding 51:10 JEPA: Building abstract representations for reasoning and planning 54:33 Open source vs. proprietary AI development 58:57 Conclusion [Source](https://www.youtube.com/watch?v=qvNCVYkHKfg)

Source quotes

[25:37] Yann LeCun: 如果你认为只要靠训练更多数据和扩大 LLM 规模就能达到人类水平的 AI,那你是在犯错。 [40:43] Yann LeCun: 理解世界的问题并不能通过在像素级别生成视频的方案来解决,绝对不行。 [12:43] Yann LeCun: 每个人都在谈论智能体系统,但除了反刍系统已经训练过的方案之外,没有人知道该怎么构建它们。 [54:33] Yann LeCun: 没有人在好点子上拥有垄断权,因此开源世界的奇迹般效率在于它能够从全球招募人才。 [5:40] Yann LeCun: 大家试图通过在不彻底推翻既有范式的前提下对其进行缝补来解决问题……就像是在 LLM 上面拧上几个螺栓,让它具备某种原始的推理功能。 [25:37] Yann LeCun: 如果你是一名投资人,投资了一家向你宣称‘只要用更多数据外加一点小技巧就能达到人类水平和博士水平 AI’的公司,我不知道你会不会输得精光,但这大概率不是个好主意。

Source quotes

[16:29] Yann LeCun: The first thing you can say is we are not going to get to human-level AI by just scaling up LLMs, this is just not going to happen. [40:44] Yann LeCun: The problem of understanding the world does not go through the solution to generating video at the pixel level. [36:28] Yann LeCun: In four years a child has seen through vision or touch for that matter as much data as the biggest LLMs, and it tells you clearly that we're not going to get to human level by just training on text. [31:58] Yann LeCun: if you think that there is some startup somewhere with five people who has discovered the secret of AGI and you should invest five billion in them, you're making a huge mistake. [54:33] Yann LeCun: Nobody has a monopoly on good ideas and so the magic efficiency of the open source world is that it recruits talents from all over the world. [43:33] Yann LeCun: In fact, it's mathematically intractable to represent distributions in high-dimensional continuous spaces.

Original transcript

[0:00] why has generative AI ingested all the [0:02] world's knowledge but not been able to [0:04] come up with scientific discoveries of [0:06] its own and has it finally starting to [0:09] understand the physical world we'll [0:11] discuss it with meta Chief AI scientist [0:13] and touring Award winner Yan laon [0:17] welcome to Big technology podcast a show [0:19] for cool-headed nuance conversation of [0:21] the tech world and Beyond I'm Alex cans [0:24] and I am thrilled to welcome Yan laon [0:26] the chief AI scientist touring Award [0:28] winner and a man known as The Godfather [0:31] of AI to Big technology podcast Yan [0:33] great to see you again welcome to the [0:35] show pleasure to be here let's start [0:37] with a question about scientific [0:39] discovery and why AI has not been able [0:42] to come up with it until this point this [0:44] is coming from dwares Patel he asked it [0:46] a couple months ago why do you make of [0:47] the fact that AIS generative AI [0:50] basically have the entire Corpus of [0:52] human knowledge memorized and they [0:53] haven't been able to make a single new [0:55] connection that has led to Discovery [0:57] whereas if even a moderately intelligent [1:00] person had this much stuff memorized uh [1:03] they would notice oh this thing causes [1:04] this symptom this other thing causes [1:06] this symptom there might be a medical [1:08] cure here so shouldn't we be expecting [1:10] that type that type of stuff from AI [1:13] well from AI yes from large NE models no [1:17] you know there's several types of AI [1:19] architectures right and and all of a [1:22] sudden when we talk about AI we imagine [1:25] chatbots chatbots LMS are trained on an [1:28] enormous amount of of knowledge which is [1:30] purely text and they're trained to [1:33] basically regurgitate to retrieve to uh [1:36] essentially produce answers that are [1:37] conform to the statistics of whatever [1:39] text they've been trained on and it's [1:42] amazing what you can do with them it's [1:43] very useful there's no question about it [1:45] uh we also know that they can [1:47] hallucinate facts that AR true uh but [1:50] they really in their purest form they [1:52] are incapable of inventing new things [1:55] let me throw out this perspective that [1:57] uh Tom Wolf from hugging face shared on [2:00] LinkedIn over the past week I know you [2:02] were involved in a discussion about it [2:04] it's very interesting he says to create [2:05] an Einstein in a data center we don't [2:08] just need a system that knows all the [2:09] answers but rather one that can ask [2:12] questions nobody else has thought or [2:14] dared to ask one that writes what if [2:16] everything everyone is wrong about this [2:19] when all texperts textbooks experts and [2:22] common knowledge suggest [2:24] otherwise is it possible to teach llm to [2:28] do that no [2:30] no not not in the current form uh I mean [2:33] and and whatever form of AI would be [2:37] able to do that will not be llms they [2:39] might use llm as one component llms are [2:42] useful to [2:44] turn uh you know to produce text okay so [2:49] we might in the future AI systems we [2:51] might use them to turn abstract thoughts [2:54] into into [2:55] language uh in the human brain that's [2:58] done by a tiny little brain area right [3:00] here called the BR area it's about this [3:01] big um that's our LM okay but we don't [3:05] think in language we think in uh you [3:09] know mental representations of a [3:11] situation we have mental models of [3:13] everything we think about we can think [3:15] even if we can speak uh and that takes [3:17] place here that's like you know where [3:20] real intelligence is and that's the part [3:22] that we haven't reproduced certainly [3:23] with with llm so the question is [3:27] um you know is are we going to have [3:30] eventually ai architectures ai systems [3:34] that are capable of U not just answering [3:38] questions that already there but solving [3:42] giving new solutions to problems that we [3:46] specify the answer is yes eventually not [3:49] with current TMS um and then the next [3:52] question is are they going to be able to [3:54] ask their own questions like figure out [3:56] what are the good questions to answer [3:58] and the answer is eventually yes but [4:00] that's going to take a while before we [4:02] get machines that are capable of this [4:03] like you know in in humans we we have [4:05] all the characteristic we have people [4:07] who are who have extremely good memory [4:09] they can um you know retrieve a lot of [4:12] things they have a lot of accumulated [4:14] knowledge um we have people who are [4:18] problem solvers right you give them a [4:20] problem they'll solve it and I think uh [4:22] Toma was actually talking about this [4:24] kind of stuff he said like you know if [4:25] you're good at school you're a good [4:26] Problem Solver we give you a problem you [4:28] can solve it um and you score well in [4:31] math or physics or whatever it is um but [4:35] then in research the the most difficult [4:37] thing is to actually ask the right to [4:39] ask the the the good questions what are [4:42] the important questions it's not just [4:44] solving the problem it's also asking the [4:46] right questions kind of framing uh a [4:50] problem you know in the right way so so [4:52] you have kind of uh new insight and and [4:56] then after that comes okay I need to [4:59] turn this into equations or into [5:01] something you know practical a model um [5:05] and that may be a different scale from [5:06] the one that as the the the right [5:08] questions might be a different scale [5:10] also to um solve equations the people [5:13] who write the equations are not [5:14] necessarily the people who write them [5:16] who who solve them um and other people [5:20] who remember that there is you know some [5:22] textbook from 100 years ago where [5:24] similar equations were solved right [5:26] those are three different skills so LMS [5:28] are really good at retrieval not good at [5:30] solving new problems get you know [5:32] finding new solutions to new problems [5:34] they can retrieve existing Solutions and [5:37] they're certainly not good at all at [5:39] asking the right questions and for those [5:41] tuning in and and learning about this [5:42] for the first time LMS is the technology [5:44] behind things like the GPT model that's [5:46] within baked within uh Chad GPT but let [5:49] let me ask you this Yan so the AI field [5:52] does seem to have moved from standard [5:53] llms to LMS that can reason uh and go [5:57] step by step and I'm curious can can you [6:00] program this this sort of [6:03] counterintuitive or uh this heretical [6:05] thinking by imbuing a reasoning model [6:08] with an instruction to question its [6:13] directives well so we have to figure out [6:15] what reasoning really mean okay and [6:17] there are um you know obviously everyone [6:19] is trying to um get [6:23] llms to reason to some extent to perhaps [6:26] be able to check whether the answer they [6:28] produced are correct [6:31] um [6:33] and the way people are approaching the [6:36] problem at the moment is that they [6:40] basically are trying to do this by [6:41] modifying the current Paradigm without [6:43] completely changing it okay so can you [6:46] you know bolt a couple WS on top of llm [6:49] so that you kind of have some [6:52] primitive um reasoning function and [6:54] that's essentially what a lot of [6:56] reasoning systems are doing you know [6:59] when way [7:00] of uh getting itms to kind of appear to [7:03] reason is Chain of Thought right so you [7:06] basically tell them to generate more [7:08] tokens than they really need to in the [7:10] hope that in the process of generating [7:12] those tokens they're going to devote [7:13] more computation to answering a question [7:16] and uh to some extent that works [7:19] surprisingly but but it's very limited [7:21] you don't actually get uh real reasoning [7:24] um out of this uh reasoning at least in [7:28] classical AI is in many domain um [7:31] involves a search through a space of [7:34] potential Solutions okay so you have a [7:36] problem to solve you can characterize [7:37] whether the problem is solved or not so [7:39] you have some way of telling whether the [7:41] problem is solved um and then you search [7:43] through a space of solutions for when [7:45] that actually satisfies the the [7:47] constraints or you know is is identified [7:50] as being a solution [7:52] um and that you know that's how that's [7:56] kind of the most general form of of [7:57] reasoning you can imagine there is no [7:59] mechanism at all in llms for this search [8:03] mechanism what you have is you have to [8:05] kind of Bolt this on top of it right so [8:07] one way to do this is you get an LM to [8:10] produce lots and lots and lots of [8:11] sequences of answers right sequences of [8:14] tokens which you know represent answers [8:16] and then you have a separate system that [8:18] picks which one is good okay this is a [8:20] bit like writing a program by sort of [8:22] randomly more or less generating [8:25] instructions um you know while maybe [8:28] respecting the grammar of the of the [8:31] language uh and then checking all of [8:33] those programs for when that actually [8:35] works it not a good way not a very [8:37] efficient way of producing correct [8:40] pieces of code it's not a good way of [8:42] reasoning uh either so um a big issue [8:46] there is is that when when humans or [8:49] animals reason we don't do it in token [8:53] space in other words when we reason we [8:55] don't have to you know generate a text [8:58] that expresses solution um and then [9:01] generate another one and then generate [9:02] another one and then among other ones we [9:04] we produce pick the one that is good we [9:07] reason internally right we have a mental [9:09] model of the situation and we manipulate [9:11] it in our head and we find kind of a [9:14] good solution when we plan a sequence of [9:16] actions to I don't know you know build a [9:18] table or something um we we plan the [9:21] sequence of action you know we have a [9:23] mental model of that in your head if I [9:25] if I tell you and this has nothing to do [9:27] with language okay so if I tell you [9:30] imagine a cube floating in front in [9:32] front of us right now now rotate that [9:35] Cube 90° along a vertical axis okay you [9:38] can imagine this this thing taking place [9:42] and you can readily observe that it's a [9:44] cube if I wrot it it 90° it's going to [9:46] look just like the cube that I started [9:49] with okay um because you have this metal [9:52] model of of a cube um and that reasoning [9:56] is in some abstract continuous space [9:58] it's not in text it's not related to [10:00] language or or anything like that um and [10:05] humans do this all the time animals do [10:06] this all the time and this is what we [10:09] yet cannot reproduce uh with with [10:12] machines yeah it reminds me you're [10:14] talking through Chain of Thought and how [10:15] it doesn't produce much novel insights [10:18] and um when deep SE came out one of the [10:20] big screenshots that was going around [10:22] was someone asking deep seek for a novel [10:25] Insight on The Human Condition and as [10:27] you read it it's one another one of [10:28] these very like clever tricks the AI PS [10:30] because it does seem like it's running [10:32] through all these different like very [10:34] interesting observations about humans [10:35] how we take our uh our our hate like our [10:40] violent side and we Channel it towards [10:41] cooperation instead of competition and [10:43] that helps us build more and then you're [10:45] like as you read The Chain of Thought [10:46] you're like this is kind of just like [10:47] you read sapiens and maybe some other [10:49] books and that's your Chain of Thought [10:51] pretty much yeah I mean yeah a lot of it [10:54] is uh regation I'm now going to move a [10:59] part the conversation I had later closer [11:01] up which is the wall uh effectively is [11:05] training standard large language models [11:07] coming close to hitting a wall whereas [11:10] before there was somewhat predictable uh [11:12] returns if you put a number a certain [11:14] amount of data and a certain amount of [11:15] compute towards training these models [11:17] you can make them predictably better um [11:21] as we're talking it seems to me like you [11:25] believe that that is eventually not [11:28] going to be true [11:29] well it I don't know if I would call it [11:31] a wall but it's certainly diminishing [11:32] return in the sense that you know we've [11:35] kind of run out of natural Text data to [11:37] train those those llms where they're [11:39] already trained with you know on the [11:41] order of uh you know 10 to the 13 or 10 [11:45] to the 14 tokens that's a lot that's a [11:48] lot and that's the the whole internet [11:50] that's all the publicly available [11:52] internet and then you know some [11:53] company's license uh uh content that is [11:56] not publicly available and then there is [11:58] talks about like you know generating [12:00] artificial data and then hiring [12:02] thousands of people to kind of you know [12:05] generate more data other knowledge phds [12:07] and professors yeah but in fact it could [12:10] be even simpler than this because most [12:11] of the systems actually don't understand [12:13] basic logic for example right so um so [12:16] to some extent you know there going to [12:18] be slow [12:19] progress uh along those lines with uh [12:22] synthetic data with you know hiring more [12:25] people to you know plug the holes in the [12:28] in the sort of you know knowledge [12:29] background of uh of uh of of those [12:32] systems but but it's diminishing return [12:34] right the the costs are ballooning of uh [12:37] generating that data and the the returns [12:40] are are are not not that great so we [12:43] need a new paradig okay we need um a new [12:47] kind of architecture of systems that at [12:50] the you know at the core are capable of [12:53] those uh search and uh um you know [12:57] searching for a good solution checking [12:58] whether that solution is good planning [13:01] for a sequence of actions to arrive at a [13:02] particular goal which is what you would [13:04] need for an agentic system to really [13:06] work everybody is talking about agentic [13:08] system nobody has any idea how to build [13:10] them other than uh basically [13:12] regurgitating plant that have the system [13:15] has already been trained on okay so you [13:17] know it's like it's like everything in [13:19] computer science you you can you can [13:21] engineer a [13:23] solution uh which is limited for for in [13:28] the context of AI [13:30] uh you [13:32] can make a system that is you know based [13:35] on on learning or retrieval with [13:37] enormous amounts of data but really the [13:39] complex things the complex thing is uh [13:42] how you build a system that can solve [13:43] new problems without being trained to [13:44] solve those problems we are capable of [13:46] doing this animals are capable of doing [13:48] this facing a new situation we can [13:51] either uh Solve IT zero shot without [13:55] without training ourselves to handle [13:57] that situation just a first time we [13:59] encounter [14:00] it or we can learn to solve it extremely [14:04] quickly so for example um you know we we [14:08] we can learn to drive in you know couple [14:11] dozen hours of practice [14:14] um and to the point that after 20 30 [14:19] hours it becomes kind of a second nature [14:21] where this become kind of subconscious [14:23] we don't don't think about it you don't [14:24] need to think about it you can speaking [14:25] of system one system two right that's [14:27] right so you know the we calls the [14:30] discussion we had with with Denny kenman [14:33] a few years ago so um you know the the [14:35] first time you drive your system too is [14:37] all uh present you have to use it to [14:40] imagine all kind of catastroph scenarios [14:42] and stuff like that right your full [14:44] attention is devoted to to driving but [14:47] then after a number of hours you know [14:49] you can talk to someone at the same time [14:50] like you don't need to think about it [14:52] it's become sort of subconscious and [14:54] more or less automatic um it's become [14:56] system one and pretty much every task [14:58] that we [14:59] you know learn that we accomplished the [15:02] first time we have to use the full power [15:04] of our of our minds and then eventually [15:06] if we repeat them uh sufficiently many [15:08] times they get they get kind of [15:10] subconscious I have this vivid memory of [15:13] uh once being in a a workshop where one [15:16] of the participants was a chess grandmas [15:18] and he played a simultaneous game [15:20] against like 50 of us right you know [15:22] going from from one person to another [15:24] you know I got wiped out in 10 turns or [15:26] something I'm terrible the chess right [15:27] but um so he would come you know come to [15:30] my my table and you [15:31] know had time to think about this cuz he [15:34] you know he was playing the other 50 [15:36] tables or something so I make my move in [15:38] front of it it goes like what and then [15:42] immediately plays so I doesn't have to [15:43] think about it um I was not a a [15:47] challenging enough opponent that he had [15:49] to actually call his system two his [15:52] system one was sufficient to beat me um [15:56] and uh what that tells you is that when [15:58] you become familiar with the task and [16:00] you you train you train yourself you [16:01] know it it kind of uh become [16:04] subconscious but the but the essential [16:07] ability of humans and many animals is [16:09] that when you face a new situation you [16:11] you [16:12] can think about it figure out a sequence [16:16] of actions a course of action to [16:18] accomplish a goal um and you don't need [16:20] to know much about about the situation [16:22] other than your common knowledge of how [16:24] the world Works basically that's what [16:26] we're missing okay with the with the I [16:28] systems [16:29] and it's okay now now I really have to [16:31] blow up the order here because youve [16:32] said some very interesting things that [16:33] we have to talk about um you talked [16:36] about how basically llms have hit the [16:39] point of diminishing returns large [16:40] language models the things that have [16:41] gotten us here and we need a new [16:43] paradigm but it also seems to me that [16:45] that new paradigm is isn't here yet and [16:49] I know you're working on the research [16:50] for it and we're going to talk about [16:52] that what the next new paradigm might be [16:54] but there's a real timeline issue don't [16:56] you think because I'm just thinking [16:59] about the money that's been raised and [17:00] put into this yes last year 6.6 billion [17:03] to open AI uh last week or a couple [17:06] weeks ago another three and a half [17:08] billion to anthropic after they raised 4 [17:10] billion uh last year Elon Musk is [17:13] putting another you know another small [17:16] fortune into into building grock these [17:19] are all llm first companies they're not [17:21] searching out the ne I mean maybe open [17:23] AI is but that 6.6 billion that they got [17:26] was because of chat GPT so [17:29] where's this field going to go because [17:31] if that money is being invested into [17:34] something that is at the point of [17:36] diminishing returns requiring a new [17:38] paradigm to progress that sounds like a [17:41] real problem well um I mean we have some [17:43] ideas about what this parad uh is the [17:46] the difficulty that I mean what we're [17:48] working on is trying to make it work um [17:51] and it's you know it's not simple that [17:52] that take that may take uh that may take [17:54] years and so the question is um is the [17:58] the all the capabilities we're talking [18:01] about perhaps through this new paradigm [18:02] that we're thinking of that we're [18:04] working on uh is it going to come uh [18:07] quickly enough to justify all all of [18:10] this uh [18:11] investment uh and if it doesn't come [18:14] quickly enough is the investment still [18:17] Justified okay so the first thing you [18:19] can say is we are not going to get to [18:22] human level AI by just scaning up LMS [18:24] this is just not going to happen Okay [18:27] that's your perspective is no way okay [18:30] absolutely no way um and and whatever [18:34] you can hear from some of my uh more [18:37] adventurous colleagues uh it's not going [18:39] to happen within the next two years [18:41] there's absolutely no way in hell to you [18:43] know pardon my French um the you know [18:47] the idea that we we're going to have you [18:48] know a country of Genius in the data [18:50] center that's complete BS right it's [18:52] absolutely no way what we're going to [18:54] have maybe is systems that are trained [18:56] on sufficiently large amounts of data [18:58] that [18:59] any question that any reasonable person [19:00] may ask will will find an answer through [19:02] those systems and it would feel like you [19:04] have you know a PhD sitting next to you [19:07] but it's not a PhD you have next to you [19:09] it's you know a system with gigantic uh [19:13] memory and retrieval ability not not a [19:16] system that can invent solutions to to [19:18] new problems um which is really what a [19:21] phg is okay this is actually it's it's [19:25] you know connected to this post that uh [19:27] Tom Tom [19:29] W made that uh um you you you [19:35] you inventing new things you know [19:38] requires [19:40] uh the the type of uh skill and [19:43] abilities that uh you're not going to [19:45] get from from from ANS so [19:49] um so this's big question which is the [19:53] investment that is being done now is not [19:55] done for tomorrow it's not it's done for [19:57] you know the next few years [19:59] and most of the investment at least for [20:01] from The Meta side is investment in uh [20:04] infrastructure for inference okay so [20:07] let's imagine that by the end of the [20:08] year which is really the plan at MAA we [20:11] have 1 billion users of meta AI through [20:15] smart glasses you know Standalone app [20:18] and and whatever um you got to serve [20:21] those people and that's a lot of [20:22] computation so that's why you need you [20:24] know a lot of investment in [20:25] infrastructure to be able to scale this [20:27] up and you know build it up over months [20:30] or or years [20:32] um and so that you know that's where [20:34] most of the money is going um at least [20:37] on on you know on the side of companies [20:39] like like like MAA Microsoft and and and [20:42] Google and potentially [20:44] Amazon [20:46] um then there is so this is just [20:49] operations essentially now is there [20:53] going to be the the market for um you [20:57] know 1 billion people using those things [20:59] regularly even if there is no change of [21:01] Paradigm and the answer is probably yes [21:04] so you know even if the revolution of [21:07] new paradigm doesn't come you know [21:08] within three years this infrastructure [21:10] is going to be used is there's very [21:11] little question about that okay so it's [21:13] a good investment and it takes so long [21:16] to set up you know data centers and all [21:19] that stuff that you need to to get [21:20] started now and plan for you know [21:23] progress to be continuous uh so that uh [21:26] you know eventually the investment is is [21:29] Justified but you can't afford not to do [21:30] it right because um because there would [21:34] be too much of a of a risk to take if [21:35] you have the cash but let's go back to [21:37] what you said the stuff today is still [21:39] deeply flawed and there have been [21:41] questions about whether it's going to be [21:43] used now meta is making this consumer [21:45] BET right the consumers want to use the [21:47] AI that makes sense open AI has 400 [21:50] million users of chat [21:51] GPT meta has three four billion I mean [21:55] basically if you have a phone three 3 [21:57] something billion [21:59] users uh 600 million users of [22:03] M right okay so more than chat jpt yeah [22:06] but but it's not used as much as so the [22:09] users are not as intense but basically [22:12] the idea that that meta can get to a [22:13] billion consumer users yeah that seems [22:16] reasonable but the thing is a lot of [22:18] this investment has been made with the [22:21] idea that this will be useful to [22:22] Enterprises uh not just a consumer app [22:25] and there's a problem because like we've [22:28] been talking about but it's not good [22:29] enough yet uh you look at Deep research [22:31] this is something Benedict devans has [22:32] brought up deep research is pretty good [22:36] but it might only get you 95% of the way [22:38] there and maybe 5% of it hallucinates so [22:41] if you have a 100 page research report [22:43] and 5% of it is wrong and you don't know [22:45] what 5% that's that's a problem and [22:48] similarly in in Enterprises [22:51] today all every Enterprise is trying to [22:53] figure out how to make uh AI useful to [22:56] them uh generative AI useful to them and [22:58] other types of AI uh but only 10% or 20% [23:03] maybe of proof of Concepts make it out [23:05] the door into production because there [23:07] it's either too expensive or it's [23:08] fallible so if this is if we are getting [23:11] to the top here uh what do you [23:15] anticipate is going to happen with with [23:17] everything that's that that has been [23:19] pushed in the anticipation that it is [23:22] going to get even better from [23:26] here well so again it's a question [23:28] timeline right when when are those [23:30] systems going to become sufficiently [23:33] reliable and intelligent so that the [23:35] deployment is made easier um but but you [23:39] know I mean this this situation you're [23:41] describing [23:43] that you know beyond the impressive [23:45] demos actually deploying systems that [23:47] are reliable is where things tend to [23:51] falter in in the use of computers and [23:55] Technologies and particularly AI this is [23:57] not new um it's it's [24:00] basically um you know why we we had [24:04] super [24:05] impressive you know autonomous driving [24:08] demos 10 years ago um but we still don't [24:12] have level five s driving cars right um [24:16] it's the last mile that's really [24:18] difficult uh so to speak for cars you [24:22] know it's you know the last the last [24:24] few that was not deliberate the you know [24:28] last few few percent of reliability [24:31] which makes a system uh practical um and [24:35] how you integrate it with sort of [24:36] existing systems and and and blah blah [24:39] blah and you know how it makes uh users [24:42] of it more efficient if you want or more [24:44] reliable or or whatever um that's where [24:49] that's where it's that's where it's [24:50] difficult um and you know this is why if [24:54] we take if we go back several several [24:55] years and we look what happened with IDM [24:58] wetson okay so wetson was going to be [25:01] the thing that you know IBM was was [25:04] going to push and generate tons of [25:06] Revenue by by having wson uh you know [25:09] learn about medicine and then be [25:11] deployed in every um every [25:14] hospital and it was basically a complete [25:17] failure and was sold for parts right um [25:20] and cost a lot of money to to IBM [25:22] including the CEO and the what happens [25:26] is that actually deploying those system [25:28] in in situations where they are reliable [25:30] and and actually help people and don't [25:34] like hurt the natural conservativism of [25:36] the of the labor force um this is where [25:40] things become complicated we're seeing [25:41] the same you know the process we're [25:43] seeing now with the difficulty of [25:44] deploying a system is not new it's it's [25:47] it's happened absolutely at at all times [25:50] this is also why you know some some of [25:53] your listeners perhaps are too young to [25:55] remember this but there was a big wave [25:56] of interest in AI in 1980s early 1980s [26:00] um around expert systems um and you know [26:04] the the hottest job in the 1980s was [26:06] going was going to be knowledge engineer [26:09] and your job was going to be to sit next [26:10] to an expert and then you know turn the [26:13] knowledge of the expert into rules and [26:15] facts that would then be fed to a um [26:19] inference engine that would be able to [26:21] kind of derive new facts and and answer [26:23] questions and blah blah blah um big wave [26:26] of interest uh the ja government started [26:29] a big program called fifth generation [26:30] computer the hardware was going to be [26:32] designed to actually take care of that [26:34] and blah blah blah you know mostly [26:36] mostly a failure there was kind of [26:40] a you know the wave of Interest kind of [26:42] died in the the mid90s about this and [26:46] and you know a few companies were [26:48] successful but basically for a narrow [26:51] set of applications for which you could [26:53] actually reduce human knowledge to a [26:55] bunch of rules and for which um it was [26:58] econom economically feasible to do so um [27:02] but the the the wide ranging impact on [27:05] all of society and industry was just not [27:07] there and so that's a denture of uh of [27:11] AI all the time um I mean the the [27:13] signals are clear that you know still um [27:17] llms with all the Bears and whistles [27:20] actually play an important role if [27:22] nothing else for information retrieval [27:24] uh you know most companies want to have [27:27] some sort of internal experts that know [27:30] all the internal documents so that any [27:32] employee can ask any question we have [27:34] one at MAA it's called Metate it's [27:36] really cool it's very useful yeah and [27:38] I'm I'm not suggesting that AI is gonna [27:41] that modern AI is not or modern general [27:43] of AI is not useful or U I'm I'm asking [27:47] purely that there's been a lot of money [27:50] that's been invested into expecting this [27:52] stuff to effectively achieve God level [27:55] capabilities and we both are talking [27:57] about how like there's you know [27:59] potentially diminishing returns here and [28:01] then what happens if there's that [28:03] timeline mismatch like you mentioned and [28:05] um this is the last question I'll ask [28:07] about it because I feel like we have so [28:08] much else to cover but I feel like [28:11] timeline mismatches uh that might be [28:13] personal to you you and I first spoke [28:16] nine years ago which is crazy now nine [28:19] years ago uh and you know about how in [28:23] the early days you had an idea for how [28:26] AI should be structured and you couldn't [28:28] even get a seat at the conferences um [28:31] and then eventually with the right [28:32] amount of when when the right amount of [28:34] compute came around those ideas started [28:35] working and then the entire AI field [28:38] took off based off of your idea that you [28:41] you worked on with Benjo and Hinton um [28:44] but and a bunch of others and many [28:46] others uh and but for the sake of [28:49] efficiency we'll say go look it up um [28:52] but just talking about those mismatch [28:54] timelines when there have been overhyped [28:56] moments uh the AI field maybe with the [28:59] expert systems that you were just [29:00] talking about and they don't pan out the [29:02] way that people expect the AI field goes [29:04] into what's called AI winter well [29:06] there's a backlash yeah correct and so [29:08] if we're going to if we are potentially [29:10] approaching this moment of mismatch [29:12] timelines do you fear that there could [29:14] be another winter now given the amount [29:16] of investment uh given the fact that [29:19] there's going to be potentially [29:20] diminishing returns with the main way of [29:22] training these things and maybe we'll [29:24] add in the fact that the market is is [29:27] the stock market looks like it's going [29:28] through a bit of a downturn right now [29:31] now that's a variable uh probably the [29:33] third most important variable of what [29:34] we're talking about but it has to factor [29:37] so I yeah I I think um I mean there's [29:40] certainly a question of timing there but [29:42] I think uh if we try to dig a little bit [29:45] deeper um as I said before if you think [29:48] that we're going to get to human level [29:49] AI by just training on more data and [29:51] scanning up LMS you're making a mistake [29:53] so if you're if you're an investor and [29:55] you invested in a company that told you [29:57] we're going to get to human level Ai and [29:59] PhD level by just you know training on [30:01] more data and with a few tricks um I [30:05] don't know if you're going to use your [30:06] shirt but that was probably not a good [30:07] idea um however there are ideas about [30:12] how to uh go forward and have systems [30:15] that are capable of doing what what [30:18] every intelligent animal and and human [30:21] are capable of doing and that current a [30:23] systems are not capable of doing and I'm [30:25] I'm talking about understanding the [30:27] physical world [30:28] um having persistent memory and being [30:30] able to reason and plan those are the [30:32] four characteristics that that you know [30:34] need to be there um and that require [30:37] systems that you know can acquire common [30:39] sense that can learn from uh natural [30:42] sensors like video as opposed to just [30:44] text just human produced uh data um and [30:48] that's a big challenge I mean I've been [30:49] talking about this for many years now [30:51] and uh and saying this is this is where [30:53] the challenge is this is what we have to [30:56] uh to figure out and and [30:58] my group and I have or people working [31:00] with me and others who have listened to [31:02] me are making progress along along this [31:05] line uh of uh system that can be trained [31:08] to understand how the world works on [31:09] video for example systems that can use [31:12] Mental models of how the world the [31:14] physical world Works to plan sequences [31:16] of actions to arrive at a particular [31:18] goal so we we have kind of early results [31:21] of this kind of systems U and there are [31:23] people at Deep mind working on similar [31:24] things and there you know people in [31:25] various universities working on this uh [31:28] so um the question is you know when is [31:31] this going to go from uh interesting [31:34] research papers uh demonstrating a new [31:37] capability with a new architecture to [31:40] you know architectures at scale that you [31:42] know are practical for a lot of [31:44] applications and can find solutions to [31:47] new problems without being trained to do [31:48] it um Etc [31:51] and you know it it's not going to happen [31:54] within the next three years but it may [31:56] happen with you know between 3 to 5 [31:58] years something like that and that's [32:00] kind of corresponds to you know the sort [32:02] of ramp up that we see in uh uh in in [32:06] investment now whether [32:09] other so so that that's the first thing [32:11] now the the second thing that's [32:12] important is that there's not going to [32:14] be one secret Magic Bullet that one [32:18] company or one group of people is going [32:20] to invent that is going to just solve [32:22] the problem um it's going to be a lot of [32:26] different ideas a lot of effort some [32:28] principles around which to base this [32:30] that that some people may may not [32:33] subscribe to and will will go um in a [32:36] direction that is you know well turn out [32:37] to be a dead end uh so there's not going [32:41] to be like a [32:43] day before which there is no AGI and [32:45] after which we have AGI this is not [32:48] going to be an event um it's going to be [32:51] continuous conceptual ideas that as time [32:55] goes by are going to be made bigger and [32:58] to scale and going to work better and [33:00] it's not going to come from a single [33:01] entity it's going to come from the [33:03] entire research Community across the [33:04] world and the people who share their [33:06] research are going to move faster than [33:08] the ones that don't and so if you think [33:11] that there is some startup somewhere [33:13] with five people who has discovered the [33:15] secret of a GI and you should invest [33:17] five billion in them you're making a [33:19] huge mistake you know Yan first of all I [33:22] always enjoy our conversations because [33:24] we start to get some real answers and I [33:25] remember even from our last conversation [33:27] I was just [33:28] and always looking back to that [33:29] conversation saying okay this is what [33:31] Yan says this is what everybody else is [33:33] saying I'm pretty sure that this is the [33:34] grounding point and that's been [33:36] corrected I know we're going to do that [33:38] with this one as well and now you've set [33:39] me up for two uh interesting threads [33:42] that we're going to pull out um as we go [33:44] on with our conversation first is the [33:47] understanding of physics and the real [33:48] world and the second is open source so [33:50] we'll do that when we come back right [33:52] after this and we're back here with Yan [33:54] laon he is the chief AI scientist at [33:57] meta the touring Award winner that we're [33:59] thrilled to have on our show luckily for [34:01] the third time um I want to talk to you [34:03] about physics Yan because there's sort [34:05] of this famous moment in big technology [34:07] podcast history and I say famous with [34:09] our listeners I don't know if it really [34:11] extended Beyond but you had [34:13] me uh uh write to chat GPT if I hold a [34:16] paper horizontally with both hands and [34:18] let it let the go let go of the paper [34:20] with my left hand uh what will happen [34:23] and uh I write it and it convincingly [34:25] says like it writes though the physics [34:27] will will happen and the paper will [34:29] float towards your left hand and I read [34:31] it out loud convinced and you're like [34:32] that thing just hallucinated and you [34:34] believed it that is what happened so [34:37] listen it's been two years I put the [34:38] test to chat PT today uh it says um when [34:43] you let go of the paper with your left [34:44] hand grav gravity will cause the left [34:46] side of the paper to drop while the [34:48] right side still held up by your right [34:50] hand remains in place this creates a [34:52] pivot effect where the paper rotates [34:54] around the point where your right hand [34:56] is hting it [34:58] so now it gets it right it learned the [35:00] lesson you know it's quite possible that [35:02] this uh um you know some someone hired [35:07] by open AI to solve the problem was fed [35:10] that question and sort of fed the answer [35:12] and the system was fine tune with the [35:13] answer I mean you know obviously you can [35:15] imagine an infinite number of such [35:18] questions and and this is where you know [35:21] uh the the the So-Cal post training of [35:23] LM becomes expensive um which is that [35:27] you know how much coverage of all those [35:28] style of questions do you have to do for [35:31] the system to basically cover 90% of or [35:34] 95% or whatever percentage of all the [35:36] questions that people may ask it um but [35:39] there you know it's there's a long tale [35:41] and there's no way you can train the [35:43] system to answer all possible questions [35:45] because there is an essentially infinite [35:47] number of them and and there is way more [35:49] question the system cannot answer that [35:52] um then questions he can it can answer [35:54] you cannot cover the set of all possible [35:56] training uh you know questions in the [35:59] training the training set right so [36:01] because I think our conversation last [36:03] time was saying you you said that [36:05] because these actions of like what's [36:07] happening with the paper if you let go [36:09] of it with your hand has not been [36:10] covered widely in text the model won't [36:13] really know how to handle it because [36:14] unless it's been covered in text the [36:16] model won't have that understanding [36:17] won't have that inherent understanding [36:19] right of the real world and I've kind of [36:21] gone with that for a while uh then I [36:24] said you know what let's let's try to [36:26] generate some AI videos [36:28] and one of the interesting things that [36:29] I've seen with the AI videos is there is [36:31] some understanding of how the physical [36:33] world works there um in a way that in [36:37] our first meeting nine years ago you [36:38] said um one of the hardest things to do [36:41] is you ask an AI what happens if you [36:43] hold a pen vertically on a table and let [36:45] go uh will it fall and there's like an [36:48] unbelievable amount of permutations uh [36:50] that can occur and it's very very [36:51] difficult for the AI to figure that out [36:54] because it just doesn't inherently [36:56] understand physics but now you go to [36:58] something like Sora uh and you say um [37:01] show me a a video of a man sitting on a [37:04] chair kicking his legs and you can get [37:08] that video and the person sits on the [37:10] chair and they kick their legs and the [37:13] legs you know don't fall out of their [37:15] sockets or stuff they Bend at the joints [37:17] and they don't have three legs and they [37:19] don't have three legs so wouldn't that [37:20] suggest an improvement of the [37:22] capabilities here with these large large [37:24] models no why because you still have [37:28] those videos produced by those uh video [37:31] generation system where you know you [37:33] spill a glass of wine and and the wine [37:36] like floats in the air or like flies off [37:38] or disappears or whatever and um so you [37:43] know of course for every specific [37:45] situation you can always collect more [37:47] data for that situation and then train [37:49] your model to handle it but that's not [37:52] really understanding the underlying [37:54] reality this is just you know [37:56] compensating [37:58] uh the the lack of understanding by uh [38:01] increasingly large amounts of data um [38:04] you know [38:05] children [38:07] understand uh you know simple Concepts [38:10] like like [38:11] gravity um with a surprisingly small [38:15] amount of [38:16] data um so in fact there is an [38:18] interesting calculation you you can do [38:21] which I've talked about publicly before [38:23] but um if you take llm typical LM train [38:27] on 30 trillion tokens something like [38:29] that right 310 to the 13 tokens a token [38:32] is about three bytes so that's .9 10 to [38:35] the 14 tokens let's say 10 to the 14 [38:37] tokens to to round this up [38:42] um that text would take any of us [38:46] probably some on the order of 400,000 [38:48] years to read right no [38:50] problem at 12 hours a day okay um [38:55] now um if for old has been awake a total [38:59] of 16,000 [39:00] hours uh you can multiply by 3600 to [39:04] give number of seconds and then you can [39:05] put a number on how like how much data [39:07] has got into your visual cortex through [39:09] the optic nerve optic nerve each optic [39:11] nerve we have two of them carries about [39:13] one meab per second roughly right so [39:16] it's 2 megabytes per second uh time 3600 [39:19] time [39:20] 16,000 and that's just about 10 to the [39:23] 14 bytes okay so in four years a child [39:26] has seen through vision or touch for [39:28] that matter as much data as the biggest [39:31] LMS and and it tells you clearly that [39:35] we're not going to get to human level by [39:36] just training on text it's just not a [39:39] rich enough source of information um and [39:41] by the way 16,000 hours is not that much [39:44] video it's 30 minutes of YouTube uploads [39:47] okay uh we can get that pretty easily [39:49] now in N months uh baby has [39:53] seen you know um let's say 10 to the 13 [39:56] bytes something which is not not much [40:00] again um and in that in that time baby [40:05] has learned basically all of intuitive [40:07] physics that that uh that that that we [40:10] know about um you know conservation [40:13] momentum gravity conservation of [40:15] momentum the fact that object don't [40:17] spontaneously disappear the fact that [40:19] they still exist even if you hide them I [40:20] mean there's all kinds of stuff you know [40:22] very basic stuff that we learn about the [40:23] world in the first few months of life um [40:26] and this is what we need to reproduce [40:28] with machine this type of learning of [40:29] you know figuring out uh what is [40:32] possible and impossible in the world [40:34] what will result from an action you take [40:36] um so that you can plan a sequence of [40:39] actions to arrive at a particular goal [40:40] that's the idea of world model and now [40:44] connected with the question about uh [40:46] video generation systems is the right [40:48] way to approach this problem to train [40:50] better and better video generation [40:52] systems and my answer to this is [40:54] absolutely no um [40:58] the the problem of understanding the [41:01] world does not go [41:03] through the solution to the to to [41:07] generating video at the pixel level okay [41:10] I don't need to know um if I if I take [41:13] this uh this glass of uh of this cup of [41:18] of water and I spill it I cannot [41:20] entirely predict you know the exact path [41:23] of that the water will will uh follow on [41:27] the table and what shape it's going to [41:28] take and all that stuff what noise it's [41:30] going to make um but at a certain level [41:33] of obstruction I can make a prediction [41:35] that the water will [41:36] spill okay and it it you know probably [41:39] make my phone wet and everything so um [41:43] so at a I can't predict all the details [41:46] but I can predict at some level of [41:48] abstraction and I think that's really a [41:51] critical concept the fact that if you [41:53] want a system to be able to learn to [41:56] comprehend [41:57] the the world and understand how the [41:59] world works it needs to be able to learn [42:03] an abstract [42:04] representation of the world that allows [42:06] you to make those prediction and um what [42:10] that means is that those architectures [42:12] will not be [42:13] generative right and uh I want to get to [42:16] your solution here in a moment but I [42:18] just wanted to also like what would a [42:20] conversation between us be without a [42:21] demo so I want to just show you I'm [42:23] going to put this on the screen when we [42:25] do the video but there's this is a video [42:27] pretty proud of I got this guy sitting [42:29] on a chair kicking his legs out and the [42:32] legs stay attached to his body and I was [42:34] like all right this stuff is making real [42:35] progress and then I said can I get a car [42:37] going into a Hy stack and so it's two [42:40] bales of hay stacks and then a Hy stack [42:43] magically emerges from the hood of a car [42:46] that's stationary and I just said to [42:48] myself okay yan yan wins again it's it's [42:52] nice car though yeah I mean the thing is [42:54] those systems have been fine tun with a [42:57] huge amount of data for humans because [42:59] you know that's that's what people are [43:01] asking most videos they ask to so so [43:04] there is a lot of data of humans doing [43:07] various things to to train those th [43:08] those uh those systems so that's why it [43:11] works for humans but not for a situation [43:13] that the the people training that system [43:16] had not anticipated so you said that the [43:18] model can't be generative to be able to [43:20] understand the real world uh you are [43:23] working on something called V jeppa JEA [43:26] JEA right V is the video you also have I [43:29] JEA for images right that is we have [43:31] jads for all kinds of stuff text also [43:34] and text so explain how that will solve [43:37] the problem of being able to allow a [43:39] machine to abstractly represent what is [43:41] going on in the real world okay so what [43:43] has made the success of [43:46] uh Ai and particularly um natural [43:50] language understanding in chatbot in the [43:52] last few years but also to some extent [43:55] computer vision is self-supervised [43:58] learning so what is self-supervised [44:00] learning it's um take an input be it an [44:03] image a video a piece of text [44:06] whatever uh corrupt it in some way and [44:10] train a big neural net to reconstruct it [44:14] basically recover the uncorrupted [44:16] version of it or the undistorted version [44:18] of it or a transformed version of it [44:20] that would result from taking an action [44:22] okay [44:24] um and you know that that would mean um [44:29] for example in the context of text take [44:31] a piece of text remove some of the words [44:32] and then train some big neural net to [44:34] prct the words that are missing take an [44:36] image remove some pieces of it and then [44:37] train bigal net to recover the full [44:39] image take a video remove a piece of it [44:42] train that to predict what's missing [44:44] okay so llms are a special case of this [44:48] where um you you you take a a text and [44:53] you train the system to just reproduce [44:55] the text and you don't need to corrupt [44:56] the text text because the system is [44:58] designed in such a way that to predict [45:00] one particular word or token in the text [45:02] it can only look at the tokens that are [45:04] to the left of it okay so so in effect [45:08] the system has hardwired into its [45:10] architecture the fact that it cannot [45:12] look at the present in the future U to [45:14] predict the present it can only look at [45:16] the past okay so but basically you train [45:19] that system to just reproduce its input [45:21] on its output okay um so this kind of [45:24] Architecture is called a causal [45:25] architecture and this is what an llm is [45:28] a large language model that's what you [45:30] know all the chatbots in the world are [45:31] are based on um take a piece of text to [45:34] and train the system to just reproduce a [45:35] piece of text on its output um and to [45:38] predict a particular word it can only [45:39] look at the word to the to the left of [45:42] it and so now what you have is a system [45:44] that given a piece of text can predict [45:46] the word that that follows um that text [45:50] and you can take [45:52] that uh that word that is predicted uh [45:55] shift it into the input and then predict [45:57] the second word shift that into the [45:59] input predict the third word that's [46:00] called Auto reive prediction it's not a [46:02] New Concept very old um so you know self [46:06] supervisor learning does not train to do [46:09] a particular does not uh train a system [46:11] to accomplish a particular task other [46:13] than capture the internal structure of [46:16] the of the data it doesn't require any [46:18] labeling by by human Okay so apply these [46:21] to images um take an image mask a chunk [46:25] of it like a bunch of [46:28] Patches from it if you want and then [46:30] train a begin on that [46:31] to reconstruct that that what is [46:35] missing and now use the internal [46:38] representation of the image learned by [46:39] the system um as input to a subsequent [46:43] Downstream task for I don't know image [46:45] recognition segmentation whatever it is [46:47] it works to some [46:48] extent but not great um so there was a [46:52] big project like this uh to do this at [46:54] Fair it's called ma Max Auto encoder [46:56] it's a special case of doing Auto which [46:59] itself is you know the sort of General [47:01] framework from which I um I derive this [47:04] this idea self supervis running so um it [47:08] doesn't work so [47:09] well um and there's various ways to you [47:12] know if you apply this to video also [47:14] I've been working on this for almost 20 [47:16] years now take a video show just the a [47:19] piece of the video and then train the [47:21] system to predict what's going to happen [47:22] next in the video so same idea as for [47:24] text but just for for video [47:28] and that doesn't work very well either [47:30] um and the reason it doesn't work why [47:32] does it work for text and not for video [47:34] for [47:35] example um and the answer [47:38] is it's easy to predict a word that [47:43] comes after a text you cannot exactly [47:45] predict which word follows a particular [47:47] text but you can produce something like [47:50] a probability distribution over all the [47:52] possible words in your dictionary all [47:53] the possible tokens is only about you [47:55] know 100 thousand possible tokens so you [47:58] you just produce a big Vector with you [48:01] know 100 thousand different numbers that [48:03] are positive and some to one okay um now [48:07] what are you going to [48:09] do to represent a probability [48:12] distribution of all possible frames in a [48:14] video or all possible missing parts of [48:17] an image we don't know how to do this [48:19] properly in fact it's mathematically [48:22] intractable to represent distributions [48:24] in high dimensional continuous spaces [48:26] okay we don't know how to do this in a [48:29] kind of useful way if you want um and so [48:33] and I've tried to you know do this for [48:35] video for a long time [48:37] um and so that is the reason why those [48:42] idea of s supervis learning using [48:44] generative models have failed so far and [48:47] this is why you know using uh you know [48:49] trying to train a video generation [48:51] system as a way to understand to get a [48:53] system to understand how the world works [48:55] that's why it's it can't [48:57] Ed um so what's the alternative the [49:00] alternative is something that is not a [49:03] gener generative architecture uh which [49:05] we call jepa so that means joint [49:07] embedding predictive architecture and we [49:09] know this works much better than [49:11] attempting to reconstruct so we we've [49:14] had uh experimental uh results on [49:18] learning good representations of of [49:21] images going back many [49:23] years where instead of taking an image [49:27] corrupting it and attempting to [49:28] reconstruct this image we take the [49:31] original full image and the corrupted [49:34] version we run them both through neural [49:36] Nets those neural Nets produce [49:38] representations of those of those two [49:41] images the initial one and the corrupted [49:45] one and we train another neur a [49:48] predictor to predict the representation [49:50] of the full image from the [49:51] representation of the corrupted one okay [49:57] and if you train a system if you [49:59] successfully train a system of this type [50:00] this this is not trained to reconstruct [50:02] anything it's just trained to learn a [50:04] representation so that you can make [50:06] prediction within the representation [50:07] layer and you have to make sure that the [50:09] representation contains as much [50:11] information as possible about the input [50:12] which is where it's difficult actually [50:14] that's the difficult part of training [50:15] those systems so that's called a jepa [50:17] joint embedding predictive [50:19] architecture um and to to train a system [50:24] to learn good representations of images [50:26] those [50:27] joint embedding architectures work much [50:29] better than the ones that are generative [50:31] that are trained by [50:32] reconstruction um and now we have a [50:34] version that works for video too so we [50:36] take a video we corrupt it by masking a [50:40] big chunk of it we run the full video [50:43] and the corrupted one through encoders [50:45] that are identical and then and [50:47] simultaneously we train a predictor to [50:49] predict the representation of the full [50:51] video from the partial one [50:53] and the representation that the system [50:56] learns of videos when you feed it to a [50:59] system that you try to tell you for [51:02] example what action is taking place in [51:03] the video or whether the video is [51:06] possible or impossible or things like [51:08] that it actually works quite well um [51:11] that's cool so it gives that abstract [51:13] thinking yeah in a way right and and we [51:15] have experimental result that shows that [51:17] this joint embedding training we have [51:19] several methods for doing this uh there [51:21] one that's called Dino another one [51:23] that's called VC rag another one that's [51:25] Vic another one that's called [51:27] IA but which is sort of distillation [51:29] method um and so we you know several [51:32] different ways to to approach this but [51:35] one of those is going to lead to a [51:38] recipe that basically gives us a general [51:40] way of training those jaer architectures [51:42] okay so it's not generative because the [51:44] system is not trying to regenerate the [51:46] part of the input it's trying to [51:48] generate a representation an abstract [51:50] representation of the input and what [51:52] that allows it to do is to ignore all [51:55] the details about the that are really [51:57] not predictable like you know the the [52:00] pen that you put on the table vertically [52:02] and when you let it go you cannot [52:04] predict in which direction is going to [52:05] fall but at some abstract level you can [52:07] say that the pen is going to fall [52:08] falling right without representing the [52:10] direction um so so that's the that's the [52:13] idea of jepa and and we're starting to [52:16] have you know good results on sort of um [52:21] having systems so VJ system for example [52:23] is train on natural lots of natural [52:24] videos and then you can show it a video [52:27] that's impossible like a video where for [52:30] example an object disappears or changes [52:32] shape okay you can generate this with a [52:34] game engine or something or a situation [52:38] where you have a ball rolling and it [52:39] rolls and it starts behind a screen and [52:43] then the screen comes down and the bll [52:44] is not there anymore right okay um so [52:47] things like this and you measure the [52:50] prediction error of the system so the [52:52] system is training to predict right and [52:54] not necessarily in time but but like [52:56] basically to predict you know the the [52:59] the sort of coherence of the video and [53:01] so you you measure the prediction error [53:04] as you show the the video to the system [53:06] and when something impossible occurs the [53:08] prediction error goes goes through the [53:10] roof and so you can detect if the system [53:13] has integrated some idea of what you [53:16] know is possible physically or what's [53:18] not possible but just being trained with [53:20] physically possible natural videos um so [53:23] that that's really interesting that's s [53:25] of the first hint [53:27] that a system is a quite suable common [53:28] sense and yes um we have versions of [53:31] those system also that are soal action [53:33] conditions so basically we have things [53:35] where we have a chunk of video or an [53:38] image of you know the state of the world [53:41] at time T and then an action is being [53:42] taken like you know a robot arm is being [53:45] moved or whatever and then of course we [53:48] can observe the the result um resulting [53:51] from this action so now what we have [53:53] when when we train a jeta with this um [53:57] the the model basically can say here is [53:59] the state of the world at time T here is [54:00] an action you might take I can predict [54:02] the state of the world at time t plus [54:03] one in this abstract representation [54:05] space there's this learning of of how [54:07] the world works of how the world works [54:08] and and the cool thing about this is [54:10] that now you can imagine you can have [54:13] the system imagine what would be the [54:15] outcome of a sequence of actions and if [54:17] you give it a goal saying like I want [54:19] the world to look like this at the end [54:21] can you figure out a sequence of actions [54:22] to get me to that point it can actually [54:24] figure out by search [54:26] for a sequence of actions that will [54:29] actually produce that result that's [54:30] planning that's reasoning that's actual [54:32] reasoning and actual planning okay I [54:34] have to get you out here where we are [54:36] over time but can you give me like 60 [54:38] seconds your reaction uh to deep seek [54:40] and sort of has open source overtaken [54:44] the propriety proprietary models at this [54:46] point and we got a limit to 60 seconds [54:48] otherwise I'm going to get uh killed by [54:50] your team here so overtaken is a is a [54:53] strong word I think uh progress is [54:55] faster in the open source world that's [54:57] for sure but of course you know uh the [54:59] pro proprietary shops are profiting from [55:02] the progress of the open source world [55:04] right they get access to that [55:06] information like everybody else um so [55:10] what what's clear is that there is many [55:11] more interesting ideas coming out of the [55:13] open source world that any single shop [55:16] as big as it can be cannot come up with [55:20] you know nobody has a monopoly and good [55:21] ideas and so the magic efficiency of the [55:25] open source world is is that uh it [55:27] recruits talents from all over the world [55:30] and so what we've seen with deeps is [55:31] that if you set up a small team with a [55:34] relatively Long Leash and few [55:37] constraints on coming up with just the [55:38] next generation of of of llms they can [55:42] actually come up with new ideas that [55:43] nobody else had come up with right they [55:45] can so reinvent a little bit what what [55:47] uh you know how you do things and then [55:49] if they share that with the rest of the [55:51] world then the entire world progresses [55:53] okay and so um [55:56] uh the the it's it it clearly shows that [56:00] um you know open source progresses [56:03] faster um and um you know a lot more [56:07] Innovation can can take place in the [56:09] open source World which the provider [56:11] world may have hard time catching up [56:13] with uh is cheaper to run what we see is [56:16] uh for you know Partners who we we talk [56:19] to um they say well our clients when [56:21] they prototype something they may use a [56:23] proprietary API but when it comes time [56:25] to actually deploy the product they [56:26] actually use Llama Or open or other open [56:29] source engines because it's cheaper and [56:31] it's more uh secure you know it's more [56:34] controllable you can run it on premise [56:36] you know there's all kinds of advantages [56:39] so um we've seen also a big evolution in [56:43] the the thinking of some people who are [56:46] initially worried that U open source [56:51] efforts uh we're going to I don't know [56:54] for example you know help the Chinese or [56:56] something something if you have like [56:57] some geopolitical reason to think it's a [56:59] bad idea um but what deeps has shown is [57:03] that the Chinese don't need us I mean [57:04] they can come up with really good ideas [57:06] right I mean we all know that there are [57:07] really really good scientists in in [57:09] China and uh one thing that is not Wily [57:12] known is that the single most cited [57:15] paper in all of science is a paper on [57:18] deep learning from 10 years ago from [57:20] 2015 and he came out of Beijing oh okay [57:24] it's uh the paper is called uh res net [57:27] so it's a particular type of [57:28] architecture of neural net where [57:30] basically by default every stage in a [57:32] deeping system confuses the identity [57:34] function it just copies its input on its [57:36] output and what the neural net does is [57:37] compute the deviation from this identity [57:40] okay so that allows to train extremely [57:43] deep neural net with you know dozens of [57:47] layers perhaps 100 layers and it was uh [57:52] the first author of that paper is [57:53] gentleman called scaming called cing her [57:55] at the time he was working at Microsoft [57:57] research Beijing MH um soon thereafter [58:01] the publication of that paper he joined [58:03] fair in California so I hired him um [58:08] and worked at Fair [58:11] for8 years or so and recently left and [58:15] is now a professor at MIT okay so uh [58:19] there are really really good scientists [58:22] everywhere around the world nobody has a [58:23] monopoly on good ideas certainly silicon [58:26] valy does not have a monopoly and good [58:28] ideas um or another example of that is [58:31] actually the first Lama came out of [58:32] Paris it came out of the fair lives in [58:35] Paris a small team of 12 people um [58:39] so um you have to take advantage of the [58:44] diversity of ideas [58:47] backgrounds uh creative juices of the [58:50] entire world if you want uh Science and [58:53] Technology to progress fast and that's [58:55] enabled by by open source Yan it is [58:58] always great to speak with you uh [59:00] appreciate this is our I think fourth or [59:01] fifth time speaking again Going Back 9 [59:04] years ago you always helped me see [59:05] through all the hype and the buzz and [59:08] actually figure out what's happening and [59:09] I'm sure that's going to be the case for [59:10] our listeners and viewers as well so y [59:13] thank you so much for coming on hope we [59:14] do it again soon thank you all right [59:16] everybody thank you for watching we'll [59:17] be back on Friday to break down the [59:19] week's news until then we'll see you [59:20] next time on big technology podcast