Feedback Loops

Feedback Loop, by GliderMaven
M: A feedback loop is a loop with high rates of transformation in its circulating matters. Some loops are not feedback loops because their velocities of transformation are slow. That is due to the presence of circulant reservoirs that reduce change. The water cycle is an example of non-feedback loop. It has oceans, lakes, and polar ice caps acting as reservoirs. Maybe less than 10% of those reservoirs undergo transformation in a thousand years via evaporation or melting. A feedback loop like the human life cycle has a much higher rate of transformations, starting from the cells of an egg and a sperm. In the movie Little Buddha, the Tibetan Buddhist teacher Lama Dorje says to the little boy Jesse that in 100 years everybody will be dead - that is impermanence. And even if some people do live longer than 100 years, the human life cycle still goes through 100% transformation in, say, 200 years.

P: That is a sobering thought. I wonder that since the water reservoirs will also transform 100% eventually, what difference does it make whether it takes 200 years or 200,000 years to complete a transformation? Why name a loop specially as feedback loop?

M: The distinction has one advantage. We can see evolution taking place much quicker in feedback loops, since evolution is about patterns of change. For example, diversity and specialization are two hallmarks of evolution. Why are there diversity like the hundreds of fish species, or specialization like the tail that they all have for swimming? These two hallmarks can be explained in terms of feedback and transformation when we get to the point of cybernetic loops, or feedback loops with governor and sensor.


Evolution of man and technology.
P: Speaking of feedback loops, I just remember the Fibonacci numbers and fractals in mathematics. How about the rock cycle and oxygen cycle? Are they feedback loops in your terminology?

M: Rock cycles are not feedback loops because the Earth’s crust is a gigantic reservoir. The oxygen cycle may be either way. I don’t know what percentage of oxygen in the atmosphere turns into carbon dioxide when living creatures breathe, or the percentage of carbon dioxide changing back to oxygen when plants photosynthesize. If the percentage is small then it is not a feedback loop. If large, then it is. When I look at the changes occurring in humanity, I see not only physical transformations, but also mental and social transformations like beliefs, feelings, wishes, relationships. They all change so very much over time. Perhaps language and culture and genes are the reservoirs in the human’s life journey. I don’t know. I am just thinking out loud. Anyway, why do feedback loops remind you of Fibonacci numbers and fractals?

P: I just read about the Fibonacci sequence and fractals the other day that they are closely related to natural growth patterns and formations. The thought of them comes up because in computer programming there are iterative loops and recursive procedures. These programs can generate Fibonacci numbers and fractal patterns in a nice, elegant way.


Goldener Schnitt Fichtenzapfen by Wolfgangbeyer at de.wikipedia
M: Iterative loops and recursive procedures? I do not speak computer lingoes. I use computers only to read emails or surf the web. That’s all. The computers are often buggy and I hate that.

P: Ah yes, computer problems. Who does not have them? Anyway, the Fibonacci numbers, 0, 1, 1, 2, 3, 5, 8, 13, 21,... follow a simple rule. Each number is the sum of the two previous numbers. 5 = 2 + 3,  8 = 3 + 5, and so on. Because of this rule a repeat or iterative loop can reproduce them easily. A recursive function can also do it and that is a hacker’s art. The feedback part is that when a number is generated, the output is fed back as an input to generate the next number.


Fibonacci Blocks
M: Neat. Like you say, the sequence of Fibonacci numbers corresponds to many natural growth patterns. What’s more, someone has noticed that the ratio of two adjacent numbers later in the sequence becomes close to 1.618. That number is called the golden ratio, and it has an important implication about natural growth.

P: Which is what, beauty? I have seen the ruin of a Greek Parthenon that was said to be built with the golden ratio somewhere. It does look grand and nice.

M: The golden ratio dictates that a population growth, following the Fibonacci sequence, is geometric in nature. The numbers in each generation is about 1.6 times of the preceding one, making the population increase ever more sharply rising. Geometric growth is what we have in the world’s human population today, which some call the population explosion. What is not said is that cancer, the abnormal growth of body tissues, is a disease where some cells are also growing geometrically in numbers.


Normal and Cancer Cell Divisions by Dorineau.
P: Huh? Are you saying cancer is natural like the Fibonacci sequence, or that human population growth is like a cancer? No, cancer is not natural. But it is kind of true the way you put it. That is strange. Populations of natural species do not grow geometrically in this world. I know rabbits can breed like crazy. But you don’t see rabbits everywhere in ever increasing numbers. Predators like coyotes and bobcats eat them.

M: That’s right. That is an example of cybernetic loops in nature that regulate population growths. Although geometric growth is natural, and cancer is that, we don’t see cancerous growth everywhere precisely because there are cybernetic loops that cut down population explosion into population balance, or ecological balance. But back to cancer. I mean to say that we need to look at cancer and its treatment differently.

P: Differently how?

M: The common notion of cancer is that it is caused by carcinogens or genetic defects. Somehow these factors make normal cells multiply like rabbits and become lumpy tumors. I suspect that normal cells can multiply like rabbits by themselves without the help of carcinogens. What the carcinogens are doing is probably damaging the regulatory mechanism of the cybernetic circuits the cells are in, resulting in some growth to become uninhibited and run away like a freight train. I have heard some cancer patients choose to forgo chemotherapy or radiation therapy that emphasize on killing the cancer cells. Instead they turn to organic whole-foods lifestyle. Some of them report that they have gotten rid of cancer successfully. I guess it is because the organic whole foods nourish the body parts damaged by carcinogens and bring them back to health. Then the balance of cybernetic regulations is restored, and cancerous growth is under control and become normal cells once again.

P: That sounds like a possibility. But are we still talking about the mind or memory?

M: Well, kind of. We are building up some contexts for talking about memory, kind of like laying out perspective lines for a drawing. Will you continue about fractals? I want to know how they relate to feedback and nature?


Fractal Broccoli by Jon Sullivan - http://pdphoto.org/PictureDetail.php?mat=pdef&pg=8232