Cybernetic Loops

M: In the iterations that generate the Fibonacci numbers and Fractals, each output is circulated back (feedback) as the new input. Such feedback loops have a geometric growth in the first case and orderly but unpredictable patterns in the second. A cybernetic loop is such a feedback loop with a sensor and a governor, which regulate the feedback circulations. That's the basic structure.


Feedback loop with sensor and controller - a cybernetic Loop.
P: I recall you mentioned something about cybernetics and robots.

M: Yes, the root of the word cybernetics means steering or governance. Robots are mechanical devices directed to act in specific ways to do work for us. Engineers design cybernetic loops into devices and those are man-made cybernetic circuits. I want to show you cybernetic loops in nature first. Have you seen the development of an embryo?

P: No, but I have heard embryology is a fascinating subject.


Gestation of embryo. Basel 2012-10-05 Batch 2 (6), by Mattes.
M: Very much so. It’s almost as if some cybernetic mechanisms are at work that direct the development of an embryo from conception to a baby. It starts with an egg fertilized and begins to divide. One single egg cell splits into two, then two to four, and four to eight and so on, till it is a newborn baby with billions and billions of cells. That’s a feedback loop phenomenon - a geometric growth like the Fibonacci sequence. Then, as the number of cells increases during gestation, the shape of the fetus appears to morph continuously. It goes from something that looks like a primitive lower life form to something that looks like a higher species. That’s also a feedback loop characteristics - a fractal pattern formation where a simple shape evolves into a complex one by iterating through some rules over and over. If we add an element of regulation into the mix (now cybernetic), then the fetus morphing becomes like a fractal pattern progression plus superimposed regulations. Suppose the effects of the superimposed regulations result in regional aggregations - shapes of organ and tissue emerge inside the body. There you have it, the development of a fetus. Who knows, maybe DNA and genes are carriers of such regulatory information. How does that sound? Wait, it goes on. Babies have tens of billions of cells. Adults have tens of trillions of cells. The cells continue to multiply in numbers after birth. When a baby leaves the womb, the internal cellular regulations are coupled with external environmental regulations - quality and quantity of food, air, sunlight, social interactions, etc. Together they mold the appearances of a person in his life journey.

P: Well! That sounds nice. The simplicity of it is nice. But I have heard that things are rarely pure and never simple. What exactly do you mean by regulation?

M: Regulation is a means to stabilize something or confine it to a certain range. Here are some examples.

1. Homeostasis such as heartbeats, body temperature, digestion. Also clapping, talking, dancing. These are natural bodily regulations. They stabilize blood circulations, metabolism rate, directions of body movements and so on.
2. Electro-mechanical regulations such as cruise control on cars, thermostat temperature control on heaters / air conditioners, volume settings on stereo gears. These are artificial machine controls.
3. Economic regulations such as planning and development, production quotas, transaction pricing, resources management. These stabilize the exchange of assets in terms of preset goals.
4. Mental regulations such as education, reasoning, perceptions, language. These stabilizes the flow of information.

Engineers, like economists, work closely on how to regulate things. They build smart machines by means of negative feedback controls - their term for the action of governor in a cybernetic loop. The world is full of artificial devices now, from coffee makers to computer printers.


by Beyond silence.
P: It’s neat that economic activities are running in cybernetic loops also. I see that each rectangle or oval box in the economic circulation diagram is a unit of regulating body. But some people do shady deeds to maximize personal fortunes and jeopardize the stability of the economy.

M: Well, there is that, playing around with regulation rules to one’s own advantage. Anyway, negative feedback is not the only type of cybernetic loops that scientists know about. What the negative feedback does in an engineer’s servo (cybernetic) circuits is that the controller (governor) is reducing the difference between its input and a threshold value. This reduction is what characterizes negative feedback. I like reduction feedback or convergence feedback better. If instead of reducing the difference of input and threshold, the controller increases it, then it is called positive feedback. I like amplification feedback or divergence feedback better. You will see how significant negative and positive feedback mechanisms are in natural phenomena. Evolution is a dance of convergences and divergences.

P: Okay, I am ready for more examples.