Claire Corlett

Fish Food, Fish Tanks, and More
How do schools of fish swim in harmony? – Nathan S. Jacobs

How do schools of fish swim in harmony? – Nathan S. Jacobs

How do schools of fish swim in harmony? And how do the tiny cells in your brain
give rise to the complex thoughts, memories, and consciousness that are you? Oddly enough, those questions have
the same general answer: emergence, or the spontaneous creation of
sophisticated behaviors and functions from large groups of simple elements. Like many animals,
fish stick together in groups, but that’s not just because
they enjoy each other’s company. It’s a matter of survival. Schools of fish exhibit
complex swarming behaviors that help them evade hungry predators, while a lone fish is quickly singled out
as easy prey. So which brilliant fish leader
is the one in charge? Actually, no one is, and everyone is. So what does that mean? While the school of fish is elegantly
twisting, turning, and dodging sharks in what looks
like deliberate coordination, each individual fish is actually
just following two basic rules that have nothing to do with the shark: one, stay close, but not too close
to your neighbor, and two, keep swimmming. As individuals, the fish are focused on
the minutiae of these local interactions, but if enough fish join the group,
something remarkable happens. The movement of individual fish
is eclipsed by an entirely new entity: the school, which has its own
unique set of behaviors. The school isn’t controlled
by any single fish. It simply emerges if you have enough fish
following the right set of local rules. It’s like an accident that happens over
and over again, allowing fish all across the ocean
to reliably avoid predation. And it’s not just fish. Emergence is a basic property of many
complex systems of interacting elements. For example, the specific way in which
millions of grains of sand collide and tumble over each other almost always produces the same
basic pattern of ripples. And when moisture freezes
in the atmosphere, the specific binding properties
of water molecules reliably produce radiating lattices
that form into beautiful snowflakes. What makes emergence so complex is that you can’t understand it
by simply taking it apart, like the engine of a car. Taking things apart is a good first step
to understanding a complex system. But if you reduce a school of fish
to individuals, it loses the ability to evade predators, and there’s nothing left to study. And if you reduce the brain
to individual neurons, you’re left with something that is
notoriously unreliable, and nothing like how we think and behave, at least most of the time. Regardless, whatever you’re thinking about
right now isn’t reliant on a single neuron
lodged in the corner of your brain. Rather, the mind emerges from
the collective activities of many, many neurons. There are billions of neurons
in the human brain, and trillions of connections between
all those neurons. When you turn such a complicated
system like that on, it could behave in all sorts
of weird ways, but it doesn’t. The neurons in our brain follow
simple rules, just like the fish, so that as a group, their activity
self-organizes into reliable patterns that let you do things
like recognize faces, successfully repeat the same task
over and over again, and keep all those silly little habits
that everyone likes about you. So, what are the simple rules
when it comes to the brain? The basic function of each neuron
in the brain is to either excite or inhibit
other neurons. If you connect a few neurons together
into a simple circuit, you can generate rhythmic patterns
of activity, feedback loops that ramp up
or shut down a signal, coincidence detectors, and disinhibition, where two inhibitory neurons
can actually activate another neuron by removing inhibitory brakes. As more and more neurons are connected, increasingly complex patterns
of activity emerge from the network. Soon, so many neurons are interacting
in so many different ways at once that the system becomes chaotic. The trajectory of the network’s activity
cannot be easily explained by the simple local circuits
described earlier. And yet, from this chaos,
patterns can emerge, and then emerge again and again
in a reproducible manner. At some point, these emergent
patterns of activity become sufficiently complex, and curious to begin studying
their own biological origins, not to mention emergence. And what we found in emergent phenomena
at vastly different scales is that same remarkable
characteristic as the fish displayed: That emergence doesn’t require
someone or something to be in charge. If the right rules are in place, and some basic conditions are met, a complex system will fall into
the same habits over and over again, turning chaos into order. That’s true in the molecular pandemonium
that lets your cells function, the tangled thicket of neurons
that produces your thoughts and identity, your network of friends and family, all the way up to the structures and
economies of our cities across the planet.

100 comments on “How do schools of fish swim in harmony? – Nathan S. Jacobs

  1. How come no one has mentioned the homage to "A Sunday Afternoon on the Island of La Grande Jatte" by Georges Seurat at 5:44?

  2. This is kind of trippy, and in a way answers the question of "who am I?" I'm just a pattern of neurological emergence…

  3. I wonder if this also applies to the universe for since each galaxy is pretty much the same shape and what if this rule might be applied to the multiverse and then the multiverse as a whole creates something like a consciousness for example… Maybe

  4. that's wow, as long as simple things in large number consistently follow a fixed set of rules, there are good chances a uniquely different set of behaviours is likely?

    will that work with simple levers?
    say the rule is that each end of a lever should be only at 2m distance from each other?

  5. Is this "emergence" something related to math. like chaos theory, with formulas and/or algorithms? If not, what is it?

  6. 0:52 глупости полные. Рыба так плавает из-за гидродинамики, а не из-за боязни быть скушанной.

  7. ok. This is very surprising coming from the US. Just one point was missing: the emergent phenomena has its own set of rules, wich can't be reduce to the rules of the single elements.

  8. The giving of an name to a phenomenon that we don't understand does not explain that phenomenon. To say, "It's emergence" is to say absolutely nothing. Saying that it happens explains nothing. In some ways, the very thing that most of these theories prove is what they do not want to prove, i.e., that consciousness does not required a brain and/or that consciousness operates as a field (see Rupert Sheldrakes work).

  9. If brain acts like school of fish. Is the school of fish controlled by some single higher mind? Or are thoughts/decisions just an illusion our brain makes and for who they make the illusion and why? :s

  10. Serious Question here. Is there a more complicated make-up of schooling fish? ie. Gravid females in the center. One can correlate that to brain function as you see fit. lol.

  11. Boids Algorithm is a set of rules to simulate that fish behavior.. It's really cool when you simulate process of nature !

  12. What a BIG BULL SHIT….I doesn't explain HOW FISH SWIM IN SCHOOLS…
    (Is because they have specialized cells to detect the closest individual)
    Really tired of these Psico mongers….TIRED!!!!

  13. "a complex system will fall into the same habits over and over again turning chaos into order" isn't this how the stock market works!!!

  14. If you know anything about computers you can thinks of these like using ones and zeros linked together to make an and gate or and or gate. Link two and gates together and all four inputs must be on etc etc which makes this collection of lights function as intended

  15. I learned two important lessons in my life today. first, stay close to people but not too close. Second, keep swimming.

  16. yes but to follow the rule "stay close but not to close" 1 fish must change direction therefore all the others are response to this change. So can we say that a "spontaneous" leader exist ? e.g. the fish which is near to the shark?

  17. I wonder if this could/was applied to software development (a methodology inspired by it). In scrum 'self organising teams' seem far more rigid than this.

  18. Please let it be noted, however, that there is no reductionist explanation for HOW the fish do this so instantaneously. We can postulate WHY, we can observe the patterns for how it looks, we can give it a fancy name like "emergence," but how they actually do this is a mystery yet to be explained by materialist science. It has been theorized that schools of fish, for example, are tuned into a single field of information, something we might liken to a group mind. But that breaks the old paradigms of science! And as far as what consciousness is… that the is biggest mystery of all, for it is the mystery trying to figure out itself!

  19. I think this is very relatable to anarchism… Close to your neighbour, but not to close; and keep going forward. So: be a community, without imposing things on others; and keep working on yourself and your goals. Kropotkin would have loved this video xD

  20. This is a simplistic way of explaining something shrouded in mystery at present . To say emergence phenomena can explain away the complex nature of swarming is being simplistic. The response of fish or birds to movement of the other is instantaneous- to depend on senses and relay information to and fro neurons takes too long!

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