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Yann LeCun raises $1B to build AI that understands the physical world

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Re: Yann LeCun raises $1B to build AI that understands the physical world

#301
post #104

Yann LeCun seeks $5B+ valuation for world model startup AMI (Amilabs). He has hired LeBrun to the helm as CEO. AMI has also hired LeFunde as CFO and LeTune as head of post-training. They’re also considering hiring LeMune as Head of Growth and LePrune to lead inference efficiency. https://techcrunch.com/2025/12/19/yann-lecun-confirms-his-ne...

The guy overseeing the funds is called LeFunde and the guy doing the fine-tuning LeTune??

Re: Yann LeCun raises $1B to build AI that understands the physical world

#302

Justifiable. There are a lot more degrees of freedom in world models. LLMs are fundamentally capped because they only learn from static text -- human communications about the world -- rather than from the world itself, which is why they can remix existing ideas but find it all but impossible to produce genuinely novel discoveries or inventions. A well-funded and well-run startup building physical world models (ground…

The term LLM is confusing your point because VLMs belong to the same bin according to Yann. Using the term autoregressive models instead might help.

Diffusion models are not autoregressive but have the same limitations

Re: Yann LeCun raises $1B to build AI that understands the physical world

#303

Earlier quoted context omitted.

> virtual simulation of 3d world Virtual simulations are not substitutable for the physical world. They are fundamentally different theory problems that have almost no overlap in applicability. You could in principle create a simulation with the same mathematical properties as the physical world but no one has ever done that. I'm not sure if we even know how. Physical world dynamics are metastable and non-linear at e…

> You could in principle create a simulation with the same mathematical properties as the physical world but no one has ever done that. I'm not sure if we even know how. What do you mean by that? Simulating physics is a rich field, which incidentally was one of the main drivers of parallel/super computing before AI came along.

The mapping of the physical world onto a computer representation introduces idiosyncratic measurement issues for every data point. The idiosyncratic bias, errors, and non-repeatability changes dynamically at every point in space and time, so it can be modeled neither globally nor statically. Some idiosyncratic bias exhibits coupling across space and time.

Reconstructing ground truth from these measurements, which is what you really want to train on, is a difficult open inference problem. The idiosyncratic effects induce large changes in the relationships learnable from the data model. Many measurements map to things that aren't real. How badly that non-reality can break your inference is context dependent. Because the samples are sparse and irregular, you have to constantly model the noise floor to make sure there is actually some signal in the synthesized "ground truth".

In simulated physics, there are no idiosyncratic measurement issues. Every data point is deterministic, repeatable, and well-behaved. There is also much less algorithmic information, so learning is simpler. It is a trivial problem by comparison. Using simulations to train physical world models is skipping over all the hard parts.

I've worked in HPC, including physics models. Taking a standard physics simulation and introducing representative idiosyncratic measurement seems difficult. I don't think we've ever built a physics simulation with remotely the quantity and complexity of fine structure this would require.

Re: Yann LeCun raises $1B to build AI that understands the physical world

#304
post #204

Justifiable. There are a lot more degrees of freedom in world models. LLMs are fundamentally capped because they only learn from static text -- human communications about the world -- rather than from the world itself, which is why they can remix existing ideas but find it all but impossible to produce genuinely novel discoveries or inventions. A well-funded and well-run startup building physical world models (ground…

> LLMs are fundamentally capped because they only learn from static text -- human communications about the world -- rather than from the world itself, which is why they can remix existing ideas but find it all but impossible to produce genuinely novel discoveries or inventions. No hate, but this is just your opinion. The definition of "text" here is extremely broad – an SVG is text, but it's also an image format. It'…

Yeah I don't even think you'd need to train it. You could probably just explain how SVG works (or just tell it to emit coordinates of lines it wants to draw), and tell it to draw a horse, and I have to imagine it would be able to do so, even if it had never been trained on images, svg, or even cartesian coordinates. I think there's enough world model in there that you could simply explain cartesian coordinates in the context, it'd figure out how those map to its understanding of a horse's composition, and output something roughly correct. It'd be an interesting experiment anyway.

But yeah, I can't imagine that LLMs don't already have a world model in there. They have to. The internet's corpus of text may not contain enough detail to allow a LLM to differentiate between similar-looking celebrities, but it's plenty of information to allow it to create a world model of how we perceive the world. And it's a vastly more information-dense means of doing so.

Re: Yann LeCun raises $1B to build AI that understands the physical world

#305

Justifiable. There are a lot more degrees of freedom in world models. LLMs are fundamentally capped because they only learn from static text -- human communications about the world -- rather than from the world itself, which is why they can remix existing ideas but find it all but impossible to produce genuinely novel discoveries or inventions. A well-funded and well-run startup building physical world models (ground…

Agree. LLMs operate in the domain of language and symbols, but the universe contains much more than that. Humans also learn a great deal from direct phenomenological experience of the world, even without putting those experiences into words. I remember a talk by Yann LeCun where he pointed out that in just the first couple of years of life, a human baby is exposed to orders of magnitude more sensory data (vision, sound, etc.) than what current LLMs are typically trained on. This seems like a major limitation of purely language-based models.

Re: Yann LeCun raises $1B to build AI that understands the physical world

#306
post #217

Earlier quoted context omitted.

That's such a terrible take. For a hot minute Meta had a top 3 LLM and open sourced the whole thing, even with LeCunn's reservations around the technology. At the same time Meta spat out huge breakthroughs in: - 3d model generation - Self-supervised label-free training (DINO). Remember Alexandr Wang built a multibillion dollar company just around having people in third world countries label data, so this is a huge br…

> - Self-supervised label-free training (DINO). Remember Alexandr Wang built a multibillion dollar company just around having people in third world countries label data, so this is a huge breakthrough. If it was a breakthrough, why did Meta acquire Wang and his company? I'm genuinely curious.

Wang fits the profile of a possible successor ceo for meta. Young, hit it big early, hit the ai book early straight out of college. Obviously not woke (just look at his public statements).

Unfotunately the dude knows very little about ai or ml research. He's just another wealthy grifter.

At this point decision making at Meta is based on Zuckerberg's vibes, and i suspect the emperor has no clothes.

Re: Yann LeCun raises $1B to build AI that understands the physical world

#307
post #228

Earlier quoted context omitted.

I think LeCun has been so consistently wrong and boneheaded for basically all of the AI boom, that this is much, much more likely to be bad than good for Europe. Probably one of the worst people to give that much money to that can even raise it in the field.

Could you please elaborate on what he was wrong about?

He said that LLMs wouldn't have common sense about how the real world physically works, because it's so obvious to humans that we don't bother putting it into text. This seems pretty foolish honestly given the scale of internet data, and even at the time LLMs could handle the example he said they couldn't

I believe he didn't think that reasoning/CoT would work well or scale like it has

Re: Yann LeCun raises $1B to build AI that understands the physical world

#308
post #30

Justifiable. There are a lot more degrees of freedom in world models. LLMs are fundamentally capped because they only learn from static text -- human communications about the world -- rather than from the world itself, which is why they can remix existing ideas but find it all but impossible to produce genuinely novel discoveries or inventions. A well-funded and well-run startup building physical world models (ground…

I don't understand this view. How I see it the fundamental bottleneck to AGI is continual learning and backpropagation. Models today are static, and human brains don't learn or adapt themselves with anything close to backpropagation. World models don't solve any of these problems; they are fundamentally the same kind of deep learning architectures we are used to work with. Heck, if you think learning from the world i…

Who knows? Perhaps attention really is all you need. Maybe our context window is really large. Or our compression is really effective. Perhaps adding external factors might be able to indirectly teach the models to act more in line with social expectations such as being embarrassed to repeat the same mistake, unlocking the final piece of the puzzle. We are still stumbling in the dark for answers.

Re: Yann LeCun raises $1B to build AI that understands the physical world

#309

Earlier quoted context omitted.

I really hate the world model terminology, but the actual low level gripe between LeCunn and autoregressive LLMs as they stand now is the fact that the loss function needs to reconstruct the entirety of the input. Anything less than pixel perfect reconstruction on images is penalized. Token by token reconstruction also is biased towards that same level of granularity. The density of information in the spatiotemporal…

Isn't the Sora video model a ViT with spatiotemporal inputs (so they've found a way to compress that down), but at the same time LeCunn wouldn't consider that a world model?

VideoGen models have to have decoder output heads that reproduce pixel level frames. The loss function involes producing plausible image frames that requires a lot of detailed reconstruction.

I assume that when you get out of bed in the morning, the first thing you dont do is paint 1000 1080p pictures of what your breakfast looks like.

LeCunns models predict purely in representation space and output no pixel scale detailed frames. Instead you train a model to generate a dower dimension representation of the same thing from different views, penalizing if the representation is different ehen looking at the same thing

Re: Yann LeCun raises $1B to build AI that understands the physical world

#310
post #236
post #234

Earlier quoted context omitted.

The premise is wrong, we are not seeing diminishing returns. By basically any metric that has a ratio scale, AI progress is accelerating, not slowing down.

For example?

For example:

The METR time-horizon benchmark shows steady exponential growth. The frontier lab revenue has been growing exponentially from basically the moment they had any revenues. (The latter has confounding factors. For example it doesn't just depend on the quality of the model but on the quality of the apps and products using the model. But the model quality is still the main component, the products seem to pop into existence the moment the necessary model capabilities exist.)

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