[HN Gopher] Differentiable Logic Cellular Automata
       ___________________________________________________________________
        
       Differentiable Logic Cellular Automata
        
       Author : eyvindn
       Score  : 413 points
       Date   : 2025-03-06 23:43 UTC (23 hours ago)
        
 (HTM) web link (google-research.github.io)
 (TXT) w3m dump (google-research.github.io)
        
       | thatguysaguy wrote:
       | This writing feels so strongly LLM flavored. It's too bad, since
       | I've really liked Alexander Mordvintsev's other work.
        
         | owenpalmer wrote:
         | Which portion of the text gave you that impression?
        
           | thatguysaguy wrote:
           | > To answer this, we'll start by attacking Conway's Game of
           | Life - perhaps the most iconic cellular automata, having
           | captivated researchers for decades
           | 
           | > At the heart of this project lies... > his powerful
           | paradigm, pioneered by Mordvintsev et al., represents a
           | fundamental shift in...
           | 
           | (Not only is this clearly LLM-style, I doubt someone working
           | in a group w/ Mordvintsev would write this)
           | 
           | > Traditional cellular automata have long captivated...
           | 
           | > In the first stage, each cell perceives its environment.
           | Think of it as a cell sensing the world around it.
           | 
           | > To do this, it uses Sobel filters, mathematical tools
           | designed to numerically approximate spatial gradients
           | 
           | Mathematical tools??? This is a deep learning paper my guy.
           | 
           | > Next, the neural network steps in.
           | 
           | ...
           | 
           | And it just keeps going. If you ask ChatGPT or Claude to
           | write an essay for you, this is the style you get. I suffered
           | through it b/c again, I really like Mordvintsev's work and
           | have been following this line of research for a while, but it
           | feels pretty rude to make people read this.
        
             | kelseyfrog wrote:
             | The reason LLMs write like that is, unsurprisingly, that
             | some people write like that. In fact many of them do - it's
             | not uncommon.
             | 
             | If you have proof like the logits are statistically
             | significant for LLM output, that would be appreciated -
             | otherwise it's just arguing over style.
        
               | thatguysaguy wrote:
               | I've read a _lot_ of deep learning papers, and this is
               | extremely atypical. I agree with you that if there were
               | any sort of serious implications then it'd be important
               | to establish proof, but in the case of griping on a forum
               | I think the standard of evidence is much lower.
        
               | Nevermark wrote:
               | > in the case of griping on a forum I think the standard
               | of evidence is much lower.
               | 
               | Uh, no. Human "slop" is no better than AI slop.
               | 
               | There is no good purpose for a constant hum of
               | predictable poorly supported "oh that's LLM" "gripes", if
               | we care about the quality of a forum.
        
               | K0balt wrote:
               | Yeah, it's disheartening that people often think my
               | writing (most of it predates gpt3) is llm, and some of my
               | favourite writers also fall under this wet blanket. LLMs
               | just copy the most common writing style, so now if you
               | write in a common way you are "llm".
        
               | 0xfffafaCrash wrote:
               | I've also had my writing misidentified as being LLM-
               | produced on multiple occasions in the last month.
               | Personally, I don't really care if some writing is
               | generated by AI if the contents contain solid arguments
               | and reasoning, but when you haven't used generative AI in
               | the production of something it's a weird claim to respond
               | to.
               | 
               | Before GPT3 existed, I often received positive feedback
               | about my writing and now it's quite the opposite.
               | 
               | I'm not sure whether these accusations of AI generation
               | are from genuine belief (and overconfidence) or some
               | bizarre ploy for standing/internet points. Usually these
               | claims of detecting AI generation get bolstered by others
               | who also claim to be more observant than the average
               | person. You can know they're wrong in cases where you
               | wrote something yourself but it's not really provable.
        
             | ziddoap wrote:
             | A lot of these are very close to stuff I have written. Not
             | saying this piece did or didn't get a pass through an LLM,
             | I have no idea, but it really makes me wonder how many
             | people accuse me of using an LLM when it's just how I
             | write.
             | 
             | I feel awful for anyone going to school now, or will be in
             | the future. I probably would have been kicked out, seeing
             | how easily people say "LLM" whenever they read some common
             | phrasing, a particular word, structure of the writing, etc.
        
               | robwwilliams wrote:
               | Ran the entire text through Claude 3.7 to evaluate style.
               | Anyone on HN can do the same.
               | 
               | I'd rather hear about the content instead of this meta
               | analysis on editorial services. Writers used to have
               | professional copy editors with wicked fine-tipped green
               | pens. Now we expect more incompetence from humans. Let me
               | add some more typos to this comment.
        
             | showmexyz wrote:
             | Reasearch papers are written like this and LLMs are trained
             | on arxiv.
        
         | K0balt wrote:
         | Are you sure you aren't just falling into the "it's all llm"
         | trap? A lot of common writing styles are similar, and the most
         | common ones are what LLMs imitate. I often am accused of llm
         | writing. I don't publish llm text because I think it is a
         | social harm, so it's pretty demoralising to have people call
         | out my writing as ""llm slop". OTOH, I have a few books
         | published and people seem to find them handy, so there's that.
        
         | BriggyDwiggs42 wrote:
         | Yup i independently noticed passages with phrases and word
         | choice mimicking llms. Certainly just used for assistance
         | though, the writing is too good overall.
        
       | 29athrowaway wrote:
       | I wonder what Stephen Wolfram has to say about this.
        
         | Rhapso wrote:
         | I wish John Conway was still around to comment.
        
       | ekez wrote:
       | There's something compelling about these, especially w.r.t. their
       | ability to generalize. But what is the vision here? What might
       | these be able to do in the future? Or even philosophically
       | speaking, what do these teach us about the world? We know a 1D
       | cellular automata is Turing equivalent, so, at least from one
       | perspective, NCA/these aren't terribly suprising.
        
         | data-ottawa wrote:
         | Potentially it would be useful if you could enter a grid from
         | satelite images and simulate wildfire spread or pollution
         | spread or similar problems.
        
         | emmelaich wrote:
         | The self-healing properties suggest biological evolution to me.
        
         | achille wrote:
         | these are going to be the dominant lifeforms on earth exceeding
         | bacteria, plants and humans in terms of energy consumption
         | 
         | cellular automata that interact with their environment, ones
         | that interact with low level systems and high level
         | institutions. to some approximation we, humans are just
         | individual cells interacting in these networks. the future of
         | intelligence aint llms, but systems of automata with metabolic
         | aspects. automata that co-evolve, consume energy and produce
         | value. ones that compete, ones that model each other.
         | 
         | we're not being replaced, we're just participants in a
         | transformation where boundaries between technological and
         | cellular systems blur and eventually dissolve. i'm very
         | thankful to be here to witness it
         | 
         | see: https://x.com/zzznah/status/1803712504910020687
        
           | ryukoposting wrote:
           | I'll have what this guy is smoking. Those visualizations are
           | pretty, though.
           | 
           | I can imagine this being useful for implementing classifiers
           | and little baby GenAI-adjacent tech on an extremely tiny
           | scale, on the order of several hundred or several thousand
           | transistors.
           | 
           | Example: right now, a lot of the leading-edge biosensors have
           | to pull data from their PPG/ECG/etc chips and run it through
           | big fp32 matrices to get heart rate. That's hideously
           | inefficient when you consider that your data is usually
           | coming in as an int16 and resolution any better than 1bpm
           | isn't necessary. But, fp32 is what the MCU can do in hardware
           | so it's what you gotta do. Training one of these things to
           | take incoming int16 data and spit out a heart rate could
           | reduce the software complexity and cost of development for
           | those products by several orders of magnitude, assuming
           | someone like Maxim could shove it into their existing COTS
           | biosensor chips.
        
             | achille wrote:
             | yes absolutely: current systems are wildly inefficient. the
             | future is one of extreme energy efficiency.
             | 
             | re smoking: sorry let me clarify my statement. these things
             | will be the dominant life forms on earth in terms of
             | metabolism, exceeding the energy consumption of biological
             | systems, over 1k petawatt hours per year, dwarfing
             | everything else
             | 
             | the lines betwen us may blur metaphorically, we'll be
             | connected to them how we're connected to ecosystems of
             | plants and bacteria. these systems will join and merge in
             | the same way we've merged with smartphones -- but on a much
             | deeper level
        
               | BriggyDwiggs42 wrote:
               | Okay so another way to put it is that these are gonna be
               | the software we run on lots of computers in the future.
               | Why this particular model of intelligence and not some
               | other one?
        
           | suddenlybananas wrote:
           | So grandiose. It's a good thing to rapture is happening when
           | you're alive to see it. You're just that important.
        
             | achille wrote:
             | i wasn't around to see the first humans land on the moon. i
             | feel a similar deep sense of awe and excitement to see this
             | revolution
        
           | ysofunny wrote:
           | because the goal of life is to maximize metabolic throughput?
           | 
           | or to minimze energetic waste?
        
       | emmelaich wrote:
       | The result checkerboard pattern is the opposite (the NOT) of the
       | target pattern. But this is not remarked upon. Is it too
       | unimportant to mention or did I miss something?
        
         | itishappy wrote:
         | They're learning features, not the exact image (that's why it's
         | so good at self healing). It should be invariant to shifts.
        
         | eyvindn wrote:
         | thanks for catching this, the figure for the target was
         | inverted when exporting for publication, corrected now.
        
           | vessenes wrote:
           | Amazing paper, I re-read it in more detail today. It feels
           | very rich, like almost a new field of study ---
           | congratulations to the authors.
           | 
           | I'm ninjaing in here to ask a q -- you point out in the
           | checkerboard initial discussion that the 5(!) circuit game of
           | life implementation shows bottom left to top right bias --
           | very intriguing.
           | 
           | However, when you show larger versions of the circuit, and in
           | all future demonstrations, the animations are top left to
           | bottom right. Is this because you trained a different
           | circuit, and it had a different bias, or because you forgot
           | and rotated them differently, or some other reason? Either
           | way, I'd recommend you at least mention it in the later
           | sections (or rotate the graphs if that aligns with the
           | science) since you rightly called it out in the first
           | instance.
        
             | miottp wrote:
             | Author here. Thank you! You're seeing that correctly. The
             | directional bias is the result of some initial symmetry
             | breaking and likely random-seed dependent. The version that
             | constructs the checkerboard from the top-right down was
             | trained asynchronously, and the one from the bottom-left up
             | was trained synchronously. The resulting circuits are
             | different.
        
       | robwwilliams wrote:
       | I wish we were all commenting about the ideas embedded in this
       | paper. It intrigues me, but is out of my comfort zone. Love to
       | read more content-related insights or criticisms rather than the
       | long thread on the shamefully smooth, engaging, and occasionally
       | rote style.
        
         | vessenes wrote:
         | I was reminded immediately of Wolfram's exploration of using
         | cellular automata to get MNIST recognition results. The
         | underlying mechanisms they both use are super different, but
         | the ideas seem like strong siblings -- I attach them in my mind
         | as saying computational complexity is almost shockingly
         | expressive, and finding ways to search around the space of
         | computation is pretty powerful.
         | 
         | That said, I put in like 4 minutes skimming this paper, so my
         | opinion is worth about the average of any Internet forum
         | opinion on this topic.
         | 
         | Anyway, I suggest reading Wolfram as well on this, it's pretty
         | provocative.
        
       | JFuzz wrote:
       | This is wild. Long time lurker here, avid modeling and simulation
       | user-I feel like there's some serious potential here to help
       | provide more insight into "emergent behavior" in complex agent
       | behavior models. I'd love to see this applied to models like a
       | predator/prey model, and other "simple" models that generate
       | complex "emergent" outcomes but on massive scales... I'm
       | definitely keeping tabs on this work!
        
       | bob1029 wrote:
       | This is very interesting. I've been chasing novel universal
       | Turing machine substrates. Collecting them like Pokemon for
       | genetic programming experiments. I've played around with CAs
       | before - rule 30/110/etc. - but this is a much more compelling
       | take. I never thought to model the kernel like a digital logic
       | circuit.
       | 
       | The constraints of boolean logic, gates and circuits seem to
       | create an interesting grain to build the fitness landscape with.
       | The resulting parameters can be directly transformed to hardware
       | implementations or passed through additional phases of
       | optimization and then compiled into trivial programs. This seems
       | better than dealing with magic floating points in the billion
       | parameter black boxes.
        
         | fnordpiglet wrote:
         | Yeah this paper feels profoundly important to me. The ability
         | to differentiate automata means you can do backward propagating
         | optimization on Boolean circuit designs to learn complex
         | discrete system behaviors. That's phenomenal.
        
       | mempko wrote:
       | There are a lot of cool ideas here. Maybe a small observation but
       | the computation is stateful. Each cell has a memory and
       | perception of it's environment. Compare this to say your modern
       | NN which are stateless. Has there been any work on statefull LLMs
       | for instance?
        
       | throwaway13337 wrote:
       | This is exciting.
       | 
       | Michael Levin best posited for me the question of how animal
       | cells can act cooperatively without a hierarchy. He has some
       | biological experiments showing, for example, eye cells in a frog
       | embryo will move to where the eye should go even if you pull it
       | away. The question I don't think he could really answer was 'how
       | do the cells know when to stop?'
       | 
       | Understanding non-hierarchical organization is key to
       | understanding how society works, too. And to solve the various
       | prisioner's delimmas at various scales in our self-organizing
       | world.
       | 
       | It's also about understanding bare complexity and modeling it.
       | 
       | This is the first time I've seen the ability to model this stuff.
       | 
       | So many directions to go from here. Just wow.
        
         | fc417fc802 wrote:
         | > The question I don't think he could really answer was 'how do
         | the cells know when to stop?'
         | 
         | I'm likely missing something obvious but I'll ask anyway out of
         | curiosity. How is this not handled by the well understood
         | chemical gradient mechanisms covered in introductory texts on
         | this topic? Essentially cells orient themselves within multiple
         | overlapping chemical gradients. Those gradients are constructed
         | iteratively, exhibiting increasingly complex spatial behavior
         | at each iteration.
        
           | cdetrio wrote:
           | Textbook models typically simulate normal development of an
           | embryo, e.g. A-P and D-V (anterior-posterior and dorsal-
           | ventral) patterning. The question Levin raises is how a
           | perturbed embryo manages to develop normally, both "picasso
           | tadpoles" where a scrambled face will re-organize into a
           | normal face, and tadpoles with eyes transplanted to their
           | tails, where an optic nerve forms across from the tail to the
           | brain and a functional eye develops.
           | 
           | I haven't thoroughly read all of Levin's papers, so I'm not
           | sure to what extent they specifically address the issue of
           | whether textbook models of morphogen gradients can or cannot
           | account for these experiments. I'd guess that it is difficult
           | to say conclusively. You might have to use one of the
           | software packages for simulating multi-cellular development,
           | regulatory logic, and morphogen gradients/diffusion, if you
           | wanted to argue either "the textbook model can generate this
           | behavior" or that the textbook model cannot.
           | 
           | The simulations/models that I'm familiar with are quite
           | basic, relative to actual biology, e.g. models of drosophila
           | eve stripes are based on a few dozen genes or less. But iiuc,
           | our understanding of larval development and patterning of C
           | Elegans is far behind that of drosophila (the fly embryo
           | starts as a syncytium, unlike worms and vertebrates, which
           | makes fly segmentation easier to follow). I haven't read
           | about Xenopus (the frogs that Levin studies), but I'd guess
           | that we are very far from being able to simulate all the way
           | from embryo to facial development in the normal case, let
           | alone the abnormal picasso and "eye on tail" tadpoles.
        
             | triclops200 wrote:
             | I'm not an expert on the actual biological mechanisms, but,
             | it makes intuitive sense to me that both of those effects
             | would occur in the situation you described from simple
             | cells working on gradients: I was one of the authors on
             | this paper during my undergrad[1] and the generalized idea
             | of an eye being placed on a tail and having nerves routed
             | successfully through the body via pheromone gradient is
             | exactly the kind of error I watched occur a dozen times
             | while collecting the population error statistics for this
             | paper. Same thing with the kind of error of a face re-
             | arranging itself. The "ants" in this paper have no
             | communication except chemical gradients similar to the ones
             | talked about with morphogen gradients. I'm not claiming
             | it's a proof of it working that way, ofc, but, even simpler
             | versions of the same mechanism can result in the same kind
             | of behavior and error.
             | 
             | [1]: https://direct.mit.edu/isal/proceedings/alif2016/28/10
             | 0/9940...
        
               | cdetrio wrote:
               | very interesting, thanks for sharing.
        
         | Jerrrrrry wrote:
         | What are Cognitive Light Cones? (Michael Levin Interview)
         | 
         | https://www.youtube.com/watch?v=YnObwxJZpZc
        
       | EMIRELADERO wrote:
       | I've been thinking a lot about "intelligence" lately, and I feel
       | like we're at a decisive point in figuring out (or at least
       | greatly advance our understanding of) how it "works". It seems to
       | me that intelligence is an emergent natural behavior, not much
       | different than classical Newtonian mechanics or electricity. It
       | all seems to boil down to simple rules in the end.
       | 
       | What if everything non-discrete about the brain is just
       | "infrastructure"? Just supporting the fundamentally simple yet
       | important core processes that do the actual work? What if it all
       | boils down to logic gates and electrical signals, all the way
       | down?
       | 
       | Interesting times ahead.
        
       | UncleOxidant wrote:
       | Is there any code available?
        
         | ysofunny wrote:
         | probably not publicly
         | 
         | why would they give their hard work away if they can keep it
         | under wraps for greater profit and a worse world riddled with
         | scarcity?
        
         | eyvindn wrote:
         | colab with all code will be available next week, will add link
         | from the article.
        
           | jimbohn wrote:
           | I'll be waiting!
        
       | showmexyz wrote:
       | Can anybody point out what's special about this?
        
         | achille wrote:
         | https://xkcd.com/676 but now much, much more efficient
        
           | showmexyz wrote:
           | So is it about learning discrete logic to solve a problem
           | rather than have whole modern CPU with all its abstraction to
           | solve the given problem?
        
         | phrotoma wrote:
         | The impression I got, and I'd be happy to have someone help me
         | improve this impression, is that it's a way to craft a CA that
         | behaves the way you want as opposed to the traditional approach
         | to studying CA's which involves tinkering with the rules and
         | then seeing what behaviour emerges.
        
           | showmexyz wrote:
           | That's what I think it is about, reverse engineering basic
           | rules from the end pattern.
        
       | alex_abt wrote:
       | > magine trying to reverse-engineer the complex, often unexpected
       | patterns and behaviors that emerge from simple rules. This
       | challenge has inspired researchers and enthusiasts that work with
       | cellular automata for decades.
       | 
       | Can someone shed some light on what makes this a problem worth
       | investigating for decades, if at all?
        
         | achille wrote:
         | yes, think of it this way: why is it that bathing the Earth
         | with 10^55 Boltzmann constants make it seemingly emit a Tesla?
         | 
         | can we construct a warm winter garment without having to
         | manually pick open cotton poppies?
         | 
         | if we place energy in the right location, can we have slime
         | mold do computation for us?
         | 
         | how do we organize matter and energy in order to watch a funny
         | cat video?
        
         | BriggyDwiggs42 wrote:
         | https://writings.stephenwolfram.com/2024/08/whats-really-goi...
         | 
         | One example is that stephen wolfram argues, I think
         | compellingly, that machine learning "hitches on to" chaotic
         | systems defined by simple rules and rides them for a certain
         | number of steps in order to produce complex behaviors. If this
         | is true, easily going in the reverse direction could give us
         | lots of insight into ML.
        
       | marmakoide wrote:
       | Self-plug here, but very related => Robustness and the Halting
       | Problem for Multicellular Artificial Ontogeny (2011)
       | 
       | Cellular automata where the update rule is a perceptron coupled
       | with a isotropic diffusion. The weights of the neural network are
       | optimized so that the cellular automata can draw a picture, with
       | self-healing (ie. rebuild the picture when perturbed).
       | 
       | Back then, auto-differentiation was not as accessible as it is
       | now, so the weights where optimized with an Evolution Strategy.
       | Of course, using gradient descent is likely to be way better.
        
       | elnatro wrote:
       | Wouldn't you need a custom non-von-Neuman architecture to
       | leverage the full power of CA?
        
         | Legend2440 wrote:
         | You can emulate a cellular automata just fine on our existing
         | computers.
         | 
         | But you could probably get better performance and power
         | efficiency if you built a computer that was more... CA-like.
         | e.g. a grid of memory cells that update themselves based on
         | their neighbors.
        
       | spyder wrote:
       | Hmm.. could this be used for the ARC-AGI challenge? Maybe even
       | combine with this recent one:
       | https://news.ycombinator.com/item?id=43259182
        
         | eyvindn wrote:
         | :)
        
       | mikewarot wrote:
       | _If I understand the article correctly,_ this research shows that
       | you can compress some 2d image into a circuit design, that if
       | replicated _exactly_ many times in a grid, it will spontaneously
       | output the desired image.
       | 
       | I'm interested in a nearby, but dissimilar project, almost it's
       | reciprocal, wherein you can generate a logic design that is NOT
       | uniform, but where every cell is independent, to allow for
       | general purpose computing. It seems we could take this work, and
       | use it to evolve a design that could be put into an FPGA, and
       | make far better utilization than existing programming methods
       | allow, at the cost of huge amounts of compute to do the training.
        
       | deadbabe wrote:
       | It seems to me this is a concept of how an AGI would store
       | memories of things it has seen or sensed and later recall them?
        
       | NeutralForest wrote:
       | Can someone ELI5 for a Muggle?
        
       | vessenes wrote:
       | Late here, but a few comments: the main idea of the authors was
       | to combine differential logic gates (an amazing invention I had
       | not heard of) with cellular automata as they say in the paper, or
       | more accurately I would say a grid topology of small neural
       | networks (cells). The cells get and send information to their
       | neighbors.
       | 
       | The idea would be you create some sort of outcome for fitness
       | (say an image you want the cells to self organize into, or the
       | rules of Conway's game of life), set up the training data, and
       | because it's fully differentiable, Bob's your uncle at the end.
       | 
       | Depending on what you think about computational complexity, this
       | may or may not shock you.
       | 
       | But since they've been doing gradient descent on differentiable
       | _logic gates_ at the end of the day, when the training is done,
       | they can just turn each cell into binary gates, think AND OR XOR,
       | etc. You then have something that can be used for inference crazy
       | fast. I presume it could also be laid out and sent to a fab, but
       | that work is left for a later paper. :)
       | 
       | This architecture could do a LOTTT of things to be clear. But
       | sort of as a warm up they use all the Conway life start and end
       | rules to train cells to implement Conway. Shockingly this can be
       | done in 5 gates(!). I note that they mention almost everywhere
       | that they hand prune unused gates - I imagine this will
       | eventually be automated.
       | 
       | They then go on to spec small 7k parameter or so neural networks
       | that when laid out in cells can self organize into different
       | black and white or color images, and can even do so on larger
       | base grids than they were trained, and are resilient to noise
       | being thrown at them. They then demonstrate that async networks
       | (each cell updates randomly) can be trained, and are harder to
       | train but more resilient to noise.
       | 
       | All this is quite a lot to take in, and spectacular in my
       | opinion.
       | 
       | One thing they mention, a lot, is that a lot of hyperparameter
       | tuning is required for "harder" problems. I can imagine like 50
       | lines of research out of this paper, but one of them would
       | certainly be adding stability in to the training process. Arc-AGI
       | is mentioned here, and is an awesome idea -- could you get a
       | "free lunch" with Arc? Or some of Arc? Different network
       | topologies are yet another interesting question, hidden
       | information, "backing layers" - e.g. why not give each cell 20
       | private cells that info goes out to and comes back in? Why not
       | make some of those cells talk to some other cells? Why not send
       | radio waves as signals across the custom topology and train an
       | efficient novel analog radio? Why not give each cell access to a
       | shared "super sized" 100k, 1mmk parameter "thinking node"? What
       | would a good topology be for different tasks?
       | 
       | I'll stop here. Amazing paper. Quite a number of PhD papers will
       | be generated out of it, I expect.
       | 
       | I'd like to see Minecraft implemented though. Seems possible.
       | Then we could have Bad Apple in Minecraft on raw circuits.
        
         | Karrot_Kream wrote:
         | Pruning excess gates will be interesting. I know this sort of
         | thing generally works with reachability analysis, but I'm
         | curious in practice how thorny this will be. Moreover I'm
         | curious how "interpretable" the resulting circuits will be.
         | 
         | Either way this research is fantastic. What a result.
        
           | vessenes wrote:
           | For sure. I guess you could run static analysis on the gates
           | to determine what "hits" and what doesn't -- I'm not a chip
           | designer, but I know the tools are super sophisticated, and
           | these are, ultimately, very small circuits.
           | 
           | I know that some early AI physics-enabled designs utilized
           | "weird" analog features, but at small geometries especially,
           | and in real life, everything is analog anyway. If these are
           | gate-level, I guess the interpretability questions will be
           | literally on assessing logic. There's so many paths to dig in
           | here, it's super interesting.
        
         | vessenes wrote:
         | an edit -- a black and white checker board can be done in 5
         | gates. Conway was more like 350 in the paper, apologies!
        
       | calebm wrote:
       | I love playing around with cellular automata for doing art. It's
       | amazing what kind of patterns can emerge (example:
       | https://gods.art/math_videos/hex_func27l_21.html). I may have to
       | try to play with these DLCA.
        
         | j_bum wrote:
         | Lovely! Thanks for sharing. Would these patterns keep
         | generating indefinitely?
        
       | max_ wrote:
       | So this does not need large training data sets like traditional
       | models?
       | 
       | The lizard and the Game of life example seem to illustate that
       | you only need one data points to create or "reverse" engineer a
       | an algorithm that "generates" something Equal to the data point.
       | 
       | How is this different from using a neural network and then over
       | fitting it?
       | 
       | Maybe that instead learning trained weights, the Cellular
       | Automata learns a combination of logic (a circuit).
       | 
       | So the underlying, problems with over fitting an neural network
       | (a model being un able to generalise) still hold for this "logic
       | cellular automata"?
        
       | juxtaposicion wrote:
       | It's interesting to see how differentiable logic/binary circuits
       | can be made cheap at inference time.
       | 
       | But what about the theoretical expressiveness of logic circuits
       | vs baselines like MLPs? (And then of course compared to CNNs and
       | other kernels.) Are logic circuits roughly equivalent in terms of
       | memory and compute being used? For my use case, I don't care
       | about making inference cheaper (eg the benefit logical circuits
       | brings). But I do care about the recursion in space and time (the
       | benefit from CAs). Would your experiments work if you still had a
       | CA, but used dumb MLPs?
        
         | scarmig wrote:
         | Well, with all 16 logic gates available, they can express all
         | Boolean circuits (you could get that even with NAND or NOR
         | gates, of course, if you are working with arbitrary as opposed
         | to fixed connectivity). And so you could have a 32 bit output
         | vector which could be taken as a float (and you could create
         | any circuit that computes any bitwise representation of a
         | real).
         | 
         | As for efficiency, it would depend on the problem. If you're
         | trying to learn XOR, a differentiable logic gate network can
         | learn it with a single unit with 16 parameters (actually, 4,
         | but the implementation here uses 16). If you're trying to learn
         | a linear regression, a dumb MLP would very likely be more
         | efficient.
        
       | srcreigh wrote:
       | The Conway's game of life example isn't so impressive. The
       | network isn't really reverse engineering rules, it's being
       | trained on data that is equivalent to the rules. It's sort of
       | like teaching + by giving it 400 data points triplets (a,b,c)
       | with 1 <= a,b <= 20 and c = a + b.
        
       | Cladode wrote:
       | Continuous relaxation of boolean algebra is an old idea with much
       | literature. Circuit synthesis is a really well-researched field,
       | with an annual conference and competition [1]. Google won the
       | competition 2 years ago. I wonder if you have tried your learner
       | against the IWLS competition data sets. That would calibrate the
       | performance of your approach. If not, why not?
       | 
       | [1] https://www.iwls.org/iwls2025/
        
       | jderick wrote:
       | Could this be used to train an LLM? It seems the hidden states
       | could be used to learn how to store history.
        
       | sim04ful wrote:
       | This is a very interesting paper. Question though: it seems the
       | cells gates since they're updated using a "global" gradient
       | descent that it isn't truly parallel.
       | 
       | Is there any promise towards a strictly local weight adjustment
       | method ?
        
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