Particle Life

This is fascinating. It's like a more complex game of life than John connoway's. It's crazy that little creatures seem to form at such small scales easily with these parameters. It's almost like the parameters of our real universe intentionally made it difficult to form life, rather than easy as some people seem to think.

There's no reason to believe life is particularly rare in the universe either, though.

There are, in fact, reasons to believe that. Nothing definitive of course. But the fact that we haven't been absorbed by a von neumann swarm or something like it places strict limits on the prevalence of life and/or what stages that life can achieve. One would either have to belive that intelligent life is vastly less likely than non-intelligent life, or that life itself is quite rare, or that life simply hasn't been around for much longer than life on earth.

I don't see not being eaten by a swarm of machines as evidence of anything - but it is interesting to me that you'd qualify all this with "or what stages that life can achieve". So simple life could be extraordinarily commonplace, and considering the context of this post...

It is a fact that we haven't been eaten by a swarm of anything. Facts are evidence. If you don't understand that, I don't think we'll be having a productive or fun converstion. Sound more like you're interested in making innane snarky comments to fuel your own ego. Good luck with that.

Would you like to actually address the point I made about simple life?

If you made a point about that, it was not clear to me. Perhaps you were implying that simple life could be very common even if intelligent life isn't. While yes, that is a possibility, that says nothing of its probability. Were that the circumstance, it leaves the question open as to why simple life would be common but intelligent life not common.

I'm just a bit confused as to why the subject of intelligent life is the focus here, considering the context of this post is basic cellular life.

As to why simple life would be more common than complex life... that seems obvious to me: simple systems are easier to emerge from chaos than complex ones.

From a cellular perspective, human cells are not really more complex than smaller multi-cellular organisms like amoebas.

Give the huge advantage that intelligence has for natural selection in complex environments, why would intelligent life not arise from simple life? It's not obvious.

From a cellular perspective, human cells are not really more complex than smaller multi-cellular organisms like amoebas.

That's a very limited and poor perspective. Yes, individual human cells are no more complex than others, but that doesn't encompass the entire system that has to emerge. A human being is - obviously, I would think - a far more complex system than a simple amoeba.

You missed the point. What's the barrier to stop simple organisms from developing into more complex and eventually intelligent systems? There's no delineation between "intelligent" and "simple" life. It's a smooth fitness landscape that evolution would (arguably) climb over time.

Evolution doesn't always work like that though. There's a fair bit of luck involved. You're right that 'intelligence' would certainly help an organism survive, but that is hardly a guarantee.

One would either have to belive that intelligent life is vastly less likely than non-intelligent life

That seems like a valid belief. Getting to a technological stage such that a species would be detectable over the vast distances of space could indeed be quite rare. You have to also consider the temporal aspect: intelligent, technologically advanced species may have evolved several times but gone extinct before we could notice them. Do other technically advanced species exist in the universe? Probably, but it could be that at any given time there might only be about 1 in any given galaxy and the distances between galaxies are great enough that we'd never likely be able to make contact. (and ~1 per galaxy would still mean that there would be a whole lot of intelligent species out there - it's just that it would be extremely difficult to make contact with any of them)

That seems like a valid belief.

Its not at all clear in general. It might be true. But it also might not. It seems quite reasonable to believe that life inevitably evolves into intelligent life if given enough time. Why some life would and some life wouldn't isn't at all clear.

advanced species may have evolved several times but gone extinct before we could notice them.

All the potential answers to the Fermi Paradox, for sure. But it would almost definitely have to be species that never got to the "expand rapidly into other solar systems" phase.

at any given time there's only about 1

This doesn't preclude us knowing about that 1. If it got to earth at any time in the last billion years, we might have a pretty high chance of discovering it if it existed on earth for any significant legnth of time.

It seems quite reasonable to believe that life inevitably evolves into intelligent life if given enough time.

From what we have seen on Earth, it does not seem inevitable. Dinosaurs were the largest land animals for a very long time and they did not, as far as we know, evolve towards being more intelligent. The same seems to be true for many other animal groups that have been around for a long time.

They don't seem to have created any technology, but it is hard to know how intelligent they were. Their brains were small, but crows have quite small brains and they are relatively intelligent. If dinosaurs had used tools, would this show up in the fossil record?

it does not seem inevitable

The belief that intelligent life isn't inevitable is not inconsistent with the belief that intelligent life usually will happen from any life given enough time. Why are you positioning those things as opposed? They are not.

But it would almost definitely have to be species that never got to the "expand rapidly into other solar systems" phase.

It's certainly not a given that our species will ever do that or that we'll last long enough to do that.

This doesn't preclude us knowing about that 1.

Let's say we're the 1 currently in the milky way galaxy. There could be another in the closest galaxy the Canis Major Dwarf Galaxy which is 25,000 light years away. But being able to detect a signal from 25,000 light years away... well, that's the problem. And what if they're just getting to the point where they could transmit a signal now? So maybe in 25,000 years we'd notice something... maybe? (if we're still around) As far as physically traveling 25,000 ly, well we know that even trying to go 1 ly is going to be super difficult technically. Similar problems even if there's an intelligent species on the other side of our own galaxy since it's 52K ly across.

There is no evidence that space travel is practical or sustainable. The only viable spaceship known to man is Earth, and we don’t steer it.

Maybe there are lots of earth-like planets with intelligent beings, but travel is impossible and communication is useless given the time delay.

It's not hard to believe that we could make self replicating drones in the next 100 years that go from system to system, make a few more, and continue. We've already sent drones out of our solar system. They don't have to go fast. They'd still visit every system in the known universe in a "relatively" small amount of time. (relative to the age of the known universe).

Turns out that the great filter was something as mundane as interstellar travel being impractical.

I think it's reasonable to say that we could probably build a fleet of ships containing tardigrades in their dried-out tun state (which is biologically inert, up to tens to hundreds of thousands of years, and extremely resilient to radiation and vacuum), launch them with enough mass to reach a nearby (up to 10 LY at 0.001c?) solar system with a planet that has water, and deliver the payload to the water, such that the tardigrades would revert to their normal living state.

It would cost a lot of money. It would take a very long time (hundreds of thousands of years). Nobody alive today would see the results. There are any number of systematic and non-systematic failures that could occur. building things that work autonomously for 100Kyears is nontrivial. Even if you succeeded- say, 100Kyears from now, one out of a thousand of your samples crash-lands onto a remote planet and revives- congratulations, you've maybe just contaminated an otherwise unknown ecosystem.

The story gets more interesting if earth has fusion, stable government and research funding, then you could make humans into tuns that can travel for 10K years, and have advanced propulsion (.01-.1c), pre-deliver full infrastructure...

Saying there is "no evidence" is factually absurd. There are a whole host of possibilities for practical long distance space travel. At very least for small light-weight robots. And it even seems possible that we can viably transport our entire solarsystem: https://www.youtube.com/watch?v=v3y8AIEX_dU . No evidence indeed... only if you lack imagination.

I honestly believe that high intelligence while short term is extremely advantageous, long term it is self-destructive.

I like to imagine there are countless planets with perfect ecosystems of living organisms where no single species dominates whole planet.

There is no such thing as a perfect ecosystem because we live in an imperfect universe, this is if you look at any significant timescale. Eventually you're going to get hit by an asteroid or a gamma ray burst, or some mega volcano is going to pop and cause world wide levels of destruction. And generally we see some reestablishment species is going to dominate for some time.

I'm curious what makes you think that. That is, of course, one of the general solutions put forth to the fermi paradox. Ie either the species develops species killing weapons (like nukes) or individuals gain massively destructive weapons. But I find these things unlikely. Even exploding all of our existing nukes in the most devastating locations would not destroy humanity or the earth. We'd bounce back - tho if such an event is inevitable, perhaps we would ride an endless wax and wane between devastating destruction events every 1000 years.

There are a number of possibilities, which depends upon what methods of interaction we are looking at.

For example, with direct contact, we can estimate a probability of life along side how possible space travel is. Perhaps space travel isn't easy or fast at all and so there is plenty of life, but it is mostly stuck to its solar systems and maybe a few neighboring stars. Overall, given that we can send and receive signals much easier than we can send and receive space crafts, I think this isn't as useful a metric.

The better one is that we don't see signals from other life elsewhere, but this still has to be measured by how likely life elsewhere would be able to see our signals.

Lastly, there is the matter of what it means to be rare. Say only 2 or 3 planets in a given galaxy end up developing intelligent life, is that rare? Given the number of galaxies in the visible universe, that is hundreds of billions if not trillions of planets with intelligent life. Yet with only 2 or 3 in a galaxy, it would be easy for us to not see any signs because maybe we are the only ones in our galaxy or our galactic neighbors are on the other side of the milky way and we have no technology to communicate, nor will we for the near future. Hundreds of billions of intelligent species can be considered both rare and not rare given the sorts of scales we are talking about.

Also other edge cases, like maybe intelligent life is common enough but it tends to rarely progress past a certain point of development due to wiping itself out. Personally, every explanation I've heard or can think of has some sort of unpleasantness to it, much like the quote that says either we are alone or we aren't alone, and both ideas are scary in their own ways.

Perhaps space travel isn't easy or fast at all

Except we have excellent knowledge about lower bounds on how easy and fast space travel can be. And its plenty fast enough to explore the entire galaxy on geological timescales. Voyager 1 is traveling at 17 km/s which would take it 1 light year every 17,700 years. Given that the galaxy is 100,000 light years across, that means that Voyager 1 could travel across the galaxy in 1.7 billion years. A spaceship built for that purpose would take vastly less time.

Voyager weighed less than 800 kg. Using the [rocket equation](https://www.omnicalculator.com/physics/ideal-rocket-equation) and a realistic exhaust velocity for methane/oxygen of 3280 m/s, you can see that you could accelerate a voyager 1 sized craft to 3000 m/s with about 1200 kg of fuel, which is less than $1 of fuel, no joke (https://www.nextbigfuture.com/2022/02/spacex-reusable-rocket...). Of course it takes a lot of money to just get that fuel into orbit: $1500/kg with a falcon heavy. But that means you could send a voyager-1-sized craft to space with the fuel it needs to achieve 3000 km/s for a mere $3 million (not including the cost of the craft itself). And harvesting methane and oxygen on smaller planets would bring down that cost by a lot.

At that speed, the craft could cross the entire galaxy in 9.6 million years. A blink of an eye on geological timescales. And if we really cared enough to spend more than a couple million dollars on this thing, we could get it there orders of magnitude faster using propulsion systems way less shitty than a methane-oxygen rocket.

With just 1% of the energy the sun outputs in a single second, you could accelerate 100 voyager 1s to 1% the speed of light.

In short, if you think space travel is a barrier, you're plainly very wrong. Even with today's technology we could send machines throughout the galaxy in a pretty short period of time. In the near future, that time will drastically reduce.

we can send and receive signals much easier than we can send and receive space crafts

And yet there are vastly larger motivations for sending a spacecraft than sending a signal. You might not be aware that nearly all radio signals that escape the earth are not powerful enough to be detectable above noise further than 1/2 a light year out. https://astronomy.stackexchange.com/questions/33939/when-do-...

There's no reason to believe we should be able to detect alien radio signals unless they are intentionally aimed at us and meant for us. Also, you can't see a radio signal that passed by 1 million years ago. Whereas you certainly would be able to see evidence of a von neumann swarm having done that.

Say only 2 or 3 planets in a given galaxy end up developing intelligent life, is that rare?

Whether anyone would consider that "rare" or not is irrelevant. The puzzle would be: if even ONE intelligent speicies existed out there more than several million years ago, why haven't we seen evidence of their space craft?

maybe intelligent life is common enough but it tends to rarely progress past a certain point of development due to wiping itself out

Yes, this is of course the premise of usual solutions to the fermi paradox. However, those solutions are often either "maybe nukes will destroy us" or "maybe something we don't know about yet will". Neither are super satisfactory as answers.

the fact that we haven't been absorbed by a von neumann swarm or something

Haven't we been? When I look all around, the whole place is simply crawling with self-replicating machines and some of them even got to a point of making first attempts to leave this planet to infect a new one.

They are less creatures than molecules. Now, mind you, as some complex sets of rules approach steady state I can pretend they are far-flung stellar empires with colors ascribed to each type of system of government (and have).

What is fooling you is the motion. This is sustained because the system has no conservation principles built in. You can make A-B pairs where B is attracted to A, A is repelled by B, and off they go, zoom. Were the meta-rules devised such that conservation of energy or momentum and such were baked in to whatever system you devised, you would see less exciting structures which would more resemble a late-stage pentamino explosion in the Game of Life.

With a sufficiently large processor, I would like to see this in three dimensions and more options for force, such as dropping off as the inverse of r or r-cubed or even r * log(r), or some "repulsive at a distance, attractive at very close quarters" particles. I have a feeling that such a system would grind to a halt even with clever optimizations.

This already does look like it has falloff... mutual attractors clearly seem more attracted to nearby particles than to larger groups further away.

I assume it falls off at inverse of r squared, which is why the person you're replying to is mentioning other functions besides that one.

I read them differently.

>> I have a feeling that such a system would grind to a halt even with clever optimizations.

I took this to mean that they thought there was no falloff calculated at all. If there is, I don't see why substituting a different function, e.g. cube vs square, would be significantly more CPU-intensive.

You focused on just one clause. Consider the whole:

1) Three dimensions, not two. Therefore distance is not the square root of (delta-x * delta-x + delta-y * delta-y) but the cube root of (delta-x * delta-x + delta-y * delta-y + delta-z * delta-z). More operations.

2) Three dimensions, not two. As you start increasing the number of dimensions, the simulation feels more and more empty. One hundred particles on a line a thousand units long is crowded. One hundred particles on a grid of one thousand by one thousand feels like more "room" for that same number of particles. In a volume of a thousand by a thousand by a thousand, one hundred particles feels too few, and one would naturally increase the number of particles. Naively, which is to say without optimizations, the number of force computed grow as N-squared. More operations.

3) Cube falloff goes by r * r * r, rather than r * r. More operations, by fifty percent. And I did suggest some more exotic functions in there which certainly could be more daunting.

1) Three dimensions, not two. Therefore distance is not the square root of (...) but the cube root of (...).

No, it is still a square root. The term under the root is correct, but distance in N dimensions (assuming euclidian space) is just sqrt(sum(delta-n ^ 2))

Hah, you're right. Serves me for typing late at night.

I would like to see this in three dimensions...

Oh, there's one of those too! I don't see ways to change the falloff though, just the magnitude...

https://hunar4321.github.io/particle-life/particle_life_3d.h...

need analog computer for that :)

Ah that's interesting, I can see how that would result in a lot more dynamic behavior.

This shows how life is emergent from simple rules.

how does it show it? what is meant by life? are rules necessary or just transitions? what enables rules at all?

A general question by those that support ideas like Intelligent Design seem to focus on the notion of order from randomness. Specifically the natural intuition is that the vast amount of order associated with life could never arise on its own from just randomness. It's encouraging to be able to so quickly demonstrate that in fact order can emerge from chaos. Even if the organelles or molecules or whatever you might consider them in these simulations don't map specifically to organelles or molecules or cells in our world, the general concept is important to understand.

where do the rules come from? Is it randomness all the way down? how come they run at all? how can a lifeform in a dynamic mess of jiggling things have a claim to understanding?

Physical and chemical properties of organic molecules give rise to emergent life-like structures/patterns. Molecules interacting via hydrogen bonding, solubility, hydrophobicity and hydrophilicity - repulsion and attraction - can produce protomembranes under the right conditions.

In this demonstration, particles with certain rules can interact in such a way that self-organizing structures emerge.

None of these simulated systems show replication evolving out of random rules though.

Not enough compute, I guess :-).

If you fully simulated RNA they would. Someone has already reproduced RNA that self-replicates.

I’m not really understanding what the “life” part of this is.

Indeed. If we described this as a "neat circular patterns simulator" would anything be lost?

Is there reproduction? Is there evolution? Is there death? It appears not. Those are essential to life.

I suspect it is called life because some of the observed patterns looks a lil bit like something you would see while peering at a petri dish on a microscope (if you squint? :-). Perhaps it is implied that with the right rules you would be able to generate "the real thing".

It's an iteration on Conway's "Game of Life".

It is amazing how easily self-sustaining structures emerge from such simple rules. Mesmerizing.

Is there any "sustaining" in the simulation? Is death a possibility? If not, then there is no "sustaining".

There was no death for the original life.

Rotting is caused by living organisms. Being eaten is caused by living organisms. Disease is caused by living organisms.

They could not die until death evolved. They could be physically destroyed but that’s not that likely.

Interesting thought. But how could death evolve when death is a prerequisite for evolution? I suppose death is a "soft" prerequisite.

This is the most interesting one I generated: https://hunar4321.github.io/particle-life/particle_life.html...

It eventually settles down to one large and unstable blob and another stable. Neither move so that's it. But before that it did what I had expected to see with objects meeting and merging

Tagging along: https://hunar4321.github.io/particle-life/particle_life.html...

This one is really fun for me. It has a lot of actions and good shapes.

This one is really dynamic: https://hunar4321.github.io/particle-life/particle_life.html...

I'd love to see this on a toroidal surface

a Mobius strip, even

The project is quite cool. I found myself tweaking for some good amount of time.

But the thing is it does not demonstrate that complexity can come from simplicity. To make a 'life' there are 8 parameters to be modified across a range and 'fine tuned' to get some tangible stable complex structure, all to be done by already conscious beings ( Users anyone? ). So much for simplicity

Well done: 3d is an option! Always wondered what emergent properties result from simple rules worlds when the dimensionality goes from 2d to 3d.

Super cool! Earlier this year I created a zero-player simulation using pygame and several AI coding assitants to see how capable they might be. In the end I had to clean up alot, but Im happy with how it turned out.

https://github.com/derekburgess/simcraft

Fascinating. This reminds me of nanopond

There is also https://exophysics.codeberg.page/ which turns particles into moving creatures.

Another similar implementation, including music responsiveness: https://vuzic.app/

I found a pretty fun set of rules: make a cycle of -0.4 between the colours (eg G->R, R->Y, Y->B, B->G in 3d or G->R, R->O, O->C, C->G in 2d) and set the other factors to 0.1.

The particles form semi-stable rotating rings until they get too close to another ring. It's quite fascinating to watch. Messing with the viscosity changes the stability and radius of the rings

I never considered it before, but by comparison this makes me realize that Conway's Game of Life is wave-based rather than particle-based. That is, in CGoL the rules apply to locations of the grid rather than objects traveling across the grid. I wonder if this system could also be constructed in a wave-based fashion?

Also, it seems like in this system the speed of light is infinite, since every particle acts on every other particle each frame, regardless of distance. In CGoL there is a speed of light, since cells can only influence their immediate neighbors each frame.

The code walkthrough was excellent and very elegant

This is a much more complete implementation, but I took a crack at this a while ago using compute shaders in Godot 4, if that's interesting to folks!

https://github.com/jasonjmcghee/compute-shaders

Very cool -- shame I don't have a wall TV to just run it on. I was however, disappointed -- I saw it as a T-shirt brand "Particle Life" for physicists. The T-shirts would have slogans such as "After listening to you, I realize you're just an unfortunate jiggle in the quantum field, so I feel totally justified in ignoring everything you say"

Reminds me of Hiroki Sayama's Swarm Chemistry:

https://www.youtube.com/watch?v=BpN-DE3o6u8

https://bingdev.binghamton.edu/sayama/SwarmChemistry/

One of my first coding projects at school was Conway's game of life, but I found the black and white a bit too boring so I pushed the assignment further by introducing RGB "genes", and give spawns a combination of their parents' colours (with random mutations).

It's very fun watching which "faction" might take over the board.

Demo: https://genetic-life.surge.sh/

Source (ported from the original C++ into Rust/WASM): https://github.com/franky47/genetic-life

What are the philosophical implications of these life models? Is it implied that life as we know it may also have a simple set of rules like this that generated it? Or is it just a game? (as in Conway's GoL).

Found some info here, seems like these are open questions [1].

1: https://en.wikipedia.org/wiki/Artificial_life#Philosophy

Particle Life Emerges from Simplicity - https://news.ycombinator.com/item?id=34156592 - Dec 2022 (1 comment)

Particle Life Simulation - https://news.ycombinator.com/item?id=33680845 - Nov 2022 (1 comment)

Particle Life - https://news.ycombinator.com/item?id=21875720 - Dec 2019 (7 comments)

Looking at the 3d js version right now. This might be my most favorite thing since the original Conway's life or maybe the old Primordial Life screen saver from the 90's. Have you considered adding shader support? I'd love to see a slowed-down more "blobby" version running full-screen. Probably turn my mac into a space heater too, but right now that's a bonus ;)

If this doesn’t convince you spontaneous life is possible I don’t know what will

offtopic: I got a new PC for xmas, and hadn't really stress tested it to make sure the fan management curve was correct. Running the linked site's demos made the fans work and they're really responsive. Cool stuff!

Life, uh, finds its particles.

I made a multithreaded Rust version of this (while learning Rust): https://github.com/bezdomniy/rust_particles

you can run it with: cargo run --release

No input yet, just randomly initialises params each run. But it runs with 4000 particles on my machine.

That's a funny coincidence, I recently made something similar: https://webgl-particle-life.netlify.app/ (source: https://github.com/ath92/particle-life)

This version does everything in webgl shaders and keeps all state for the simulation in textures / uniforms. This allows it to simulate and draw more particles. Unfortunately it may not run on all devices because it uses some less supported webgl extensions.

This is so great!!! Nice work!

That's impressive.

I had a similar concept in mind when I started experimenting in 3D with what I now call "Altphy" (alternative physics), but I've not been able to really make it work as intended (really, is far from working). Also probably the logic and idea behind it too much for real time processing. I'm sharing it only because maybe pieces of that code (or the idea itself) can progress into something one day.

source: https://github.com/aDeveloperCase/altphy

Even with such a basic system you immediately start to get self-organising little bubbles of life. If something had a way to replicate in these bubbles, you would have the first cell.

Mixing up Conway's game with colorful 'genes' is pretty wild, like coding with a rainbow palette. And about those blobs – it's like they're putting on their own little drama show, then just decide to chill. Also, gotta love the action and cool shapes in that simulation. It's like a mini superhero movie, but with shapes instead of characters.

I watched the Youtube video on this yesterday and have been itching to try a webgl shader implementation ever since.

Really liked it

If anyone is more interested in this kind of stuff, then I can recommend checking out "Smooth-life" and "Lenia", the latter of which has a couple different, more complex variants... "Flow Lenia" or "Particle Lenia" come to mind in relation to this particular (pun intended) topic.