Why Fei-Fei Li and Yann LeCun Are Both Betting on "World Models"
47 comments
·November 14, 2025ripe
And the pendulum swings back toward representation. It is becoming clear that the LLM approach is not adequate to reach what John McCarthy called human-level intelligence:
Between us and human-level intelligence lie many problems. They can be summarized as that of succeeding in the "common-sense informatic situation". [1]
And the search continues...
modeless
Danijar Hafner just left DeepMind. He's behind the Dreamer series of models which are IMO the most promising direction for world models anyone has come up with yet. I'm wondering where he's headed. Maybe he could end up at LeCun's startup?
In Dreamer 4 they are able to train an agent to play Minecraft with enough skill to obtain diamonds, without ever playing the game at all. Only by watching humans play. They first build a world model, then train the agent purely in scenarios imagined by the world model, requiring zero extra data or experience. Hopefully it's obvious how generating data from a world model might be useful for training agents in domains where we don't have datasets like the entire internet just sitting around ready-made for us to use.
andrewflnr
If I was smarter, I would have predicted that not only would everyone else figure out that world models are a critical step, but that as a direct consequence the term "world model" would lose all meaning. Maybe next time. That said, Le Cunn's concept in the blog post is the only one worthy of the title.
yannyu
The naming collision here is unfortunate since the two kinds of models described couldn't be any more different in purpose. Maybe JEPA-type world models should explicitly be called "predictive world models".
Marshferm
Control theory and cog-sci are impaired ideas. There is no mind, and cog sci is a post hoc retrofit narrated onto brains, rather than experience as events integrated. Cog sci is words sportscasting synthetic categories.
LeCun's model will fail as the idea of world model is oxymoronic, brains don't need them and the world isn't modeled, all models are wrong, the world is experienced instantaneously in optic flow that's built atop of olfaction.
https://www.eneuro.org/content/7/4/ENEURO.0069-20.2020
Any real AI that veers at control will have to adopt a neurobio path
https://tbrnewsmedia.com/sbus-sima-mofakham-chuck-mikell-des...
That's built paradoxically from unpredictability
CrackerNews
The first link is about how philosophy and psychology is used to describe brain-cognitive behavior research, which has a limited explanatory capability compared to a hypothetical interpretation using its own vocabulary instead of those borrowed from other fields.
The second link is about an AI that detects consciousness in coma patients.
The third link is about how coma is associated with a low-complexity and high-predictability passive cortical state. Kickstarting the brain to a high-complexity and low-predictability state of cortical dynamics is a sign of recovery back to consciousness.
How does any of this support what you have said?
ryandv
> There is no mind
Interesting. What is your response to the cogito?
MangoToupe
All abstraction of reality are bound to fail, but some abstractions are more convincing (or indeed more useful) than others.
> Any real AI that veers at control will have to adopt a neurobio path
Maybe. Or maybe it's a useless distraction. Only time will tell what signals are meaningful.
Marshferm
Neuro is the experience integrating allo/egocentric. We've already crossed that threshold in vision depth meets allocortex behaviors in entertainment. Ie there's more intelligence in The Shining than anything in current folk science AI/cog sci. It's a resounding flop, so will the Gaussian and the psychobabble of LeCuns as it is a psychological approach.
IntrepidPig
I always felt like one of reasons LLMs are so good is that they piggyback on the many years that have gone into developing language as an information representation/compression format. I don’t know if there’s anything similar a world model can take advantage of.
That being said there have been models which are pretty effective at other things that don’t use language, so maybe it’s a non issue.
ares623
I will gladly take $10B to find out for you.
allenleee
With all due respect, AI is ultimately a capital game. World models aren’t where real B2B customer revenue comes from—at least compared to today’s LLMs; they’re mainly a better story for raising huge amounts of private capital. Hopefully they figure out how to build the next-gen AI architecture along the way.
imvetri
By capital game, do you mean money investment game or market ruler's game?
MangoToupe
> World models aren’t where real B2B customer revenue comes from
You could say the same thing about AGI. Ultimately capital will realize intelligence is a drawback.
echelon
The most useful models are image, video, and audio models. It makes sense that we'd make the video models more 4D aware.
Text really hogged all the attention. Media is where AI is really going to shine.
Some of the most profitable models right now are in music, image, and video generation. A lot of people are having a blast doing things they could legitimately never do before, and real working professionals are able to use the tools to get 1000x more done - perhaps providing a path to independence from bigger studios, and certainly more autonomy for those not born into nepotism.
As long as companies don't over-raise like OpenAI, there should be a smooth gradient from next gen media tools to revolutionary future stuff like immersive VR worlds that you can bend like the Matrix or Holodeck.
And I'll just be exceedingly chuffed if we get open source and highly capable world models from the Chinese that keep us within spitting distance of the unicorns.
BriggyDwiggs42
>Some of the most profitable models right now are in music, image, and video generation.
I don’t think many of the companies running these make a profit right now
danielmarkbruce
>> The most useful models are image, video, and audio models
This is wrong. The vast majority of revenue is being generated by text models because they are so useful.
Aperocky
That just sounds like text with extra steps.
Fundamentally what AGI is trying to do is to encode ability to logic and reason. Tokens, images, video and audio are all just information of different entropy density that is the output of that logic reasoning process or emulation of logic reasoning process.
ryandv
> Fundamentally what AGI is trying to do is to encode ability to logic and reason.
No? The Wason selection task has shown that logic and reason are not really core nor essential to human cognition.
It's really verging on speculation, but see chapter 2 of Jaynes 1976 - in particular the section on spatialization and the features of consciousness.
nine_zeros
[dead]
ThrowawayTestr
AI might be the biggest transfer of wealth from the rich to the poor in history. Billions have been poured into closed sourced models which have led directly and indirectly to open weight models being available to everyone.
breppp
At the cost of buying the poor's thoughts (training data)
yannyu
Pretty similar to social media in a lot of ways. They've strip mined the commons and provided us a corporate controlled walled garden to compensate us for our loss.
BriggyDwiggs42
Open weight models aren’t worth very much money to most people.
philipkiely
I played with Marble yesterday, Fei-Fei/World Labs' new product.
It is the most impressed I've been with an AI experience since the first time I saw a model one-shot material code.
Sure, its an early product. The visual output reminds me a lot of early SDXL. But just look at what's happened to video in the last year and image in the last three. The same thing is going to happen here, and fast, and I see the vision for generative worlds for everything from gaming/media to education to RL/simulation.
nmfisher
I wasn't actually able to use it because the servers were overloaded. What exactly impressed you (or more generally, what does it actually let you do at the moment?).
philipkiely
You give it a text prompt and optional image.
What you get is a 3D room based on the prompt/image. It rewrites your prompt to a specific format. Overall the rooms tend to be detailed and imaginative.
Then you can fly around the room like in Minecraft creative mode. Really looking forward to more editing features/infill to augment this.
CrackerNews
Marble appears to be like HunyuanWorld to me, but this time they marketed it as a first step to a world model, and it has multimodal capabilities.
techblueberry
I don’t know enough about this to be sure, but this feels like a white whale.
andrewflnr
Human-level language was a white whale just a few years ago.
krainboltgreene
A.L.I.C.E. was published in '95.
Fricken
A trillion dollars are now riding on that white whale. An entire naval fleet is being raised for the purposes of chasing down that whale. LeCun and Fei-Fei merely believe that the whale is in a different ocean.
CrackerNews
I think video and agentic and multimodal models have led to this point, but actually making a world model may provide to be long and difficult.
I feel LeCun is correct that LLMs as of now have limitations where it needs an architectural overhaul. LLMs now have a problem with context rot, and this would hamper with an effective world model if the world disintegrates and becomes incoherent and hallucinated over time.
It'd doubtful whether investors would be in for the long haul, which may explain the behavior of Sam Altman in seeking government support. The other approaches described in this article may be more investor friendly as there is a more immediate return with creating a 3D asset or a virtual simulation.
SilverElfin
Everytime I see LeCun talk about world models, I can’t help but think it is also just a tweak on the fundamentals of what is behind current LLM technology. In the end it’s still neural networks. To me, having to “teach” the model how physics works makes me think it can’t be true AGI either.
benatkin
Whether or not this is exactly the same thing, I find this glossary entry from NVIDIA interesting: https://www.nvidia.com/en-us/glossary/world-models/
skywhopper
Because they are smart enough to realize current LLM tech is nearing a dead end and cannot serve as a full AGI, even ignoring context and hallucination issues, without actual knowledge of the real world.
lumost
Most world models so far are based on transformers, no?
LLMs are parameter based representations of linguistic representations of the world. Relative to robot predictive control problems, they are low dimensional and static. They are batch trained using supervised learning and are not designed to manage real time shifts in the external world or the reward space. They work because they operate in abstract, rule governed spaces like language and mathematics. They are ill suited to predictive control tasks. They are the IBM 360s of AI. Even so, they are astonishing achievements.
LeCun is right to say that continuous self supervised (hierarchical) learning is the next frontier, and that means we need world models. I'm not sure that JEPA is the right tool to get us past that frontier, but at the moment there are not a lot of alternatives on the table.