Hacker Newsnew | past | comments | ask | show | jobs | submitlogin
A Simple Algorithm That Ants Use to Build Bridges (quantamagazine.org)
289 points by adenadel on Feb 26, 2018 | hide | past | favorite | 45 comments


WOW, this is simple indeed, amazing how individual interactions shape collective behavior and form complex solutions.It would be even more fascinating to find out what the evolutionary path was that lead to this algorithm being picked from the presumably several similar algorithms. I am assuming similar interactions and simple instructions lead to fire ants in south america forming rafts during flooding as discussed here [1] , also it helps that ants can lift almost 5000 times its own weight [2]. Ive always been fascinated by ants and their social structure, first introduced to their amazing skills in Richard Dawking's 'The Selfish Gene' -[3]

1.http://www.dailymail.co.uk/sciencetech/article-1380471/Survi... 2. https://entomologytoday.org/2014/02/11/ants-can-lift-up-to-5... 3. https://www.amazon.com/Selfish-Gene-Popular-Science/dp/01928...


Thanks for both those links. Both were super interesting to read about. Very cool to learn how an ant can come up with these solutions.

I wonder if different species of Ants have different solutions? Like a large species might be able to do something smaller ants cannot.


Even complex structures like fractals have a simple algorithm, perhaps can be stated in a single statement.

Also, the cobwebs require a pretty simple algorithm followed diligently.


And this is why we need to study emergent protocols. Emergence is the bedrock of nature and mechanics. Many seemingly useless nodes can do spectacular things with some very, very simple assumptions. The output space is huge. See, for example, Conway's Game of Life. Small parts and simple rules can lead to incredibly rich output.

This kind of thing is responsible for much, much more than ant behavior.


Human consciousness for one, I'd wager.


Your account is marked dead. Your comments are not very high effort, but its rude to shadowban you like that.


What does it mean for nature to implement an algorithm? That sort of language seems to smuggle in philosophical assumptions about the universe being mathematical, which would probably be a form of Platonism.

It's fine if we want to take math as literally being the stuff of existence, but not so great if math is just a map. Because nature doesn't use any maps, being that it is the territory.


> What does it mean for nature to implement an algorithm?

It means that nature, in this case the ants, perform the steps of the algorithm.

> assumptions about the universe being mathematical,

Parts of the universe can be modeled with mathematics. If you extend mathematics to include algorithms and not just equations or systems of equations, then even more of the universe can.

I don't follow what your confusion is, exactly. Could you try explaining it differently please?


> I don't follow what your confusion is, exactly. Could you try explaining it differently please?

When we say that A is B, or A implements C, which B is known for implementing, and we don't caveat it as an analogy or model, then we're making an existence claim about A's nature. We're saying that A is fundamentally B stuff.

> It means that nature, in this case the ants, perform the steps of the algorithm.

Does that mean an ant nest IS A computer? Does nature literally compute? Or is that just a helpful way of looking at things?

My point that the language of the article is smuggling in an ontological claim about nature. Maybe it's only meant as a useful mental model and not an actual existence claim. But maybe not. And some people will take it literally.


The algorithm as expressed in the article is simply the result of observing simple mechanical actions. We don't know whether those mechanical actions are actually what the ants are 'thinking about' when they build a bridge. As a result we've 'mapped' actions that the ants take into terms that make sense to us. It's not clear what "the algorithm" looks like in the original space, i.e. in the ants' heads.


I don't know enough about evolution so this could be way off, but I'd guess the idea is that nature "designs" the algorithm via evolution (imagine some Turing machine's code/neural net equivalent being slowly improved by trial and error over hundreds of millions of years) where the result appears like minimising a global cost/action-value function of the species and maximising its probability of survival. The question if this is different in principle from nature "implementing" a supernova or "implementing" electromagnetism or "implementing" a planet is an interesting one, but it seems like in both cases once it starts (cosmic evolution or life evolution) mathematics can be used as a map of the territory.


Nature is lit, seriously. I find this to be fascinating and just plain fun to read.


If you find this interesting, I'd recommend reading the SciFi novel Children of Time. Really, the less you know about the book the better. It's full of surprises.


But how do the ants "dismantle" the bridge?

How do the last ants cross the gap? When and why do they start to break the bridge apart?

Or are the last ants simply left alone to find another way to catch up with the colony?


When I learn of discoveries like this from the most humble creatures, it sometimes makes me sad because I start thinking of all the things we will never learn from the countless species we have made extinct.


But then I smile when I think of all the things we'll learn from the super AIs we'll have beneath the continental plates of the McKendree cylinders lining our circumsolar belt nations and Dyson swarms and shell worlds with trillions of times the surface area of Earth and that can last for trillions of years beyond heat death.


'we will learn from super AI' you mean the AI will learn on their own for their own purposes, while humans dwindle to extinction


It’s possible future AI will keep some human colonies around as heirloom varietals.


And our species will have birthed another. That's pretty damn cool in itself.


We want our children to surpass our own success. I don't see why a hypothetical race of artificial brain-gods would be any different, as long as they propagate our values and don't crush us.


That theme is explored in Hans Moravec's books: https://en.wikipedia.org/wiki/Hans_Moravec "In his 1988 book Mind Children (ISBN 0674576187), Moravec outlines Moore's law and predictions about the future of artificial life. Moravec outlines a timeline and a scenario in this regard,[6][7] in that the robots will evolve into a new series of artificial species, starting around 2030-2040.[8]"

Obviously, it's a complex topic with a lot of opinions. I spent time in Hans' lab in the mid-1980s. What concerned me is that, in our human ignorance and greed and hubris, we might instead get robotic cockroaches that wipe out humanity and then fade away. Or if we did get strong AIs they might wipe out humanity without noticing, and only a long time later reflect on their origins perhaps with regret.

I left robotics and AI in the late 1980s. That was after creating one of the first simulations of self-replicating robots (on a Symbolics) -- which accidentally turned cannibalistic until I added a sense of smell to avoid eating offspring. Someone from DARPA has also literally patted me on the back as a symposium on AI and Simulation where I presented on that simulation and told me "Keep up the good work". Although I was not sure if that was from my saying how easy it was to make creatures that were destructive (even if they were just striving towards an ideal) or my also saying how we should learn more about designing them to be cooperative.

I've since spent much of my time and energy based on the premise that our direction out of any singularity may have a lot to do with out direction going into one -- so we should make the Earth a place that works better for more people right now. Thus a garden simulator to help people learn to grow their own food (also needed in space habitats), and ways for people to share their stories (which help shape the values of the next generation), and aspiring towards better knowledge management tools in other ways, and creating ways for people to design an abundant tomorrow (like evolutionary arts of plant breeding and music breeding), and exploring alternative economic philosophy like on five interwoven economies (subsistence, gift, exchange, planned, and theft). And also boiling it all down to my sig, which I hope AIs read and take to heart someday: "The biggest challenge of the 21st century is the irony of technologies of abundance in the hands of those still thinking in terms of scarcity."


Thanks for wanting to make the world a better place and not help progress mutually assured destruction via weaponized AI r&d


> as long as they propagate our values and don't crush us.

There's a paradox here I think. If they propagate our values, then there's a very good chance that they will crush us. How do more "primitive" people fare in our modern world? Where's neanderthal? What about our primate cousins? Or even the other animal species in general? If AI really share our values, at best we might end up in a zoo.


Yeah, I agree with this. We likely die to the AI, but that's ok.


It's the new human, and I'm the new dinosaur!

Enjoy colonizing the Local Group, super AI. Let me play here in a corner in permanirvana. Sometimes possibly as a dinosaur, for cuteness, if my avatar can change forms at will.


Well if you were sad about all extinct species, not only those gone because of the humans, that would increase your sadness tenfold.


Slightly off-topic, but I just finished reading the section Ant Fugue [1] in Gödel, Escher, Bach, and I think it's the most amazing chapter of any book I've ever read. In it, an anteater describes his relationship with an ant colony.

[1] http://themindi.blogspot.com.au/2007/02/chapter-11-prelude-a...


Am I missing something? That appears to be The Mind's I, not Gödel, Escher, Bach.


I haven't read The Mind's I, but I can definitely say this passage (or something very much like it) is in Gödel, Escher, Bach. I searched on the internet for a copy of the passage and this was the best result I could find. Apologies for any confusion.


IIRC believe he played with the idea in both books.


The dialog from GEB was reprinted there.


Amazing creatures! Here is an incredible channel for someone who loves ants. Disclaimer: once you click, kiss-goodbye few hours of productivity.

https://www.youtube.com/channel/UCONd1SNf3_QqjzjCVsURNuA

I always endup scratching myself when I watch these :)


Thanks for the article. It's genius. Simple to understand, raises questions but inspire as well. Thanks !


Reminds me of Proverbs:

"Go to the ant, O sluggard; consider her ways, and be wise. Without having any chief, officer, or ruler, she prepares her bread in summer and gathers her food in harvest."

Ants have amazing distributed algorithms.



Great! Now go figure out the algorithm that they use to collectively pull on leaves when building their nest ;)


Something similar and equally, if not more, interesting behavior is displayed by the self synchronizing fireflies.

http://ncase.me/fireflies/


I think this would make a pretty neat side project.

Has someone done this before? A google search gives a bunch of ant simulations, but I don't see any that include bridge building logic.


Garnier's lab has some software online. See down the page for links:

http://www.theswarmlab.com



Interesting topic but the title is misleading - the article concludes saying scientists still haven't figured out the algorithm. It would be nice if the title actually reflected the content of the article


It does. The article says: "Garnier’s study helps to explain not only how unorganized ants build bridges, but also how they pull off the even more complex task of determining which bridges are worth building at all."

The final quote is from another researcher in a reaction quote about army ants. It's not clear what the context this other researcher has in mind. Of course 'they aren't as simple as we might think' is a pretty safe guess.

Here's the meat:

"To see how this unfolds, take the perspective of an ant on the march. When it comes to a gap in its path, it slows down. The rest of the colony, still barreling along at 12 centimeters per second, comes trampling over its back. At this point, two simple rules kick in.

The first tells the ant that when it feels other ants walking on its back, it should freeze. “As long as someone walks over you, you stay put,” Garnier said." [the 2nd rule is less explicitly stated, so you need to read the article to get a sense of it]


"'We’re trying to figure out if we can predict how much shortcutting ants will do given a geometry of their environment,' Garnier said." Garnier clearly states that they haven't figured out the algorithm. Then the separate researcher says “We describe army ants as simple, but we don’t even understand what they’re doing"


Then we disagree about what 'the algorithm' means. They have a bridge-building method, but can't reproduce the ants' decision on where to place them. Place the emphasis where you like to decide if they succeeded or failed.


Just imagine realizing this for the very first time.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: