The term steady state has a well accepted meaning in fields of science and engineering. It characterizes a condition, state or phase of a dynamic system where change is no longer occuring and a stable situation has been achieved. One may say that the system has matured. This is not to say that things have become static or stagnant. On the contrary, the term is usually applied to a dynamic system where the forces that influence the stability or instability of the system are in constant flux.
A static system is one where not only the condition is stable and unchanging but also the forces or influences acting on the system are unchanging. A ball resting on a table may be stable and static and so is a car parked on your driveway. One would not expect the ball or the car to move unless someone disturbed it.
On the other hand, the same ball tied to a string and hanging from a tree will eventually stop swinging and reach a steady state. If a strong wind blows, the ball is temporarily disturbed and set in motion. Once the wind stops, the ball will eventually return to its original stable position. Now imagine a strong wind blowing continuously and steadily so that the string suspending the ball is no longer vertical but at an angle away from vertical. In such a situation, the ball can still reach a steady-state condition where the force of the wind on the ball is equally matched by the force of gravity. The two forces balance each other and we say that the ball is in dynamic equilibrium. The distinction between dynamic equilibrium and steady state will not be made here.
As another example, a car being driven at a constant speed on the highway may attain steady-state condition, not the position of the car but its speed or velocity. If the driver is conscientious and law abiding, he may choose to keep his foot on the gas pedal exactly so as to maintain the speed of the car at the speed limit. The speed has now reached steady state. The forces causing the car to slow down are wind and road resistances and the driver compensates for these by regulating the amount of power the engine exerts. An unconscientious driver may choose to attain a different steady-state condition at a higher speed. Of course this steady-state condition is abruptly lost in the event of a collision or on the presence of a highway law enforcement patrol car and a new steady state condition will be attained.
Steady state can be applied to social and economic systems as well. When people approach a busy gas station or a long line-up at the coffee sales counter, they might choose not to wait in line. Therefore the length of the queue may reach a steady-state condition based on the rapidity at which customers are being served countered by the willingness or unwillingness of having to wait in line for a long time.
The fixed and finite non-renewable resources of our earth will set their own limits on how we consume these natural resources. Copper metal is used extensively as an electrical conductor, conduit for plumbing and as coinage. It is also heavily used to create brass, a very attractive metal used extensively to create ornaments, musical instruments and many household items. Once all naturally occurring sources of copper have been discovered and extracted, the world's supply of copper will have matured and attained steady-state status. Continued usage of copper will rely on reusing and recycling what has been used before such as copper wire, old coins etc. The same can be said for all other metals such as aluminum, iron, silver, zinc, etc.
The population of living things eventually reaches a mature stage and steady state may be the result. When a destructive virus invades another organism the viral population may grow to the point that it overwhelms its host henceforth killing it. Since the host has been destroyed, the viral population will also be destroyed. This is the phenomenon we call overshoot and crash.
When we study population growth of animals, birds and insects such as caribou, buffalo or bison, penguins and gypsy moths, etc., we can appreciate how population growth becomes limited by the amount of space available to roam and feed. When the environment is compromised and food supply declines, we see a limit to how large the population can become. We call this the carrying capacity of the environment. Sometimes we experience overshoot and crash. Other times we may reach steady state.
In science, we study the number of ways in which a dynamic system may progress. In the first case, a quantity may exhibit an oscillatory behavior which may go on indefinitely. In a second case, weak forces may limit growth which eventually reaches a steady-state condition but not without experiencing wild excursions. This is called under-damped oscillation. In a third case, strong forces limiting growth may exist resulting in over-damping and growth occurs at suppressed and diminishing rates. The final case in which the quantity approaches a steady-state condition in a smooth controlled manner is called critical damping. Understanding these concepts is essential to scientists and engineers who design simple control systems such as the thermostat in our homes as well as highly complex control systems such as that of a nuclear reactor.
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Positive Feedback aka the Vicious Cycle It's late fall and the Indians on a remote reservation in South Dakota asked their new chief if the coming winter was going to be cold or mild. Since he was a chief in a modern society, he had never been taught the old secrets. When he looked at the sky, he couldn't tell what the winter was going to be like. Nevertheless, to be on the safe side, he told his tribe that the winter was indeed going to be cold and that the members of the village should collect firewood to be prepared. But, being a practical leader, after several days, he got an idea. He went to the phone booth, called the National Weather Service and asked, "Is the coming winter going to be cold?" "It looks like this winter is going to be quite cold", the meteorologist at the weather service responded.
So the chief went back to his people and told them to collect even more firewood in order to be prepared. A week later, he called the National Weather Service again. "Does it still look like it is going to be a very cold winter?"
'"Yes", the man at National Weather Service again replied, "it's going to be a very cold winter".
The chief again went back to his people and ordered them to collect every scrap of firewood they could find. Two weeks later, the chief called the National Weather Service again. "Are you absolutely sure that the winter is going to be very cold?"
"Absolutely", the man replied. "It's looking more and more like it is going to be one of the coldest winters we've ever seen".
'How can you be so sure?", the chief asked. The weatherman replied, "The Indians are collecting firewood like crazy." |
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Real life examples of the Vicous Cycle going from bad to worse: 1) Government attempts to tackle the budget deficit by curtailing social services and cutting jobs. Workers are laid off and have less money to spend. Tax revenue declines and that makes the deficit worse. 2) Pressure on the housing market depresses house prices. As prices fall
below their mortgaged value, owners default on payments. Homes are foreclosed
and put up for sale. A surplus of homes for sale forces prices downward
triggering more foreclosures. Supply outpaces demand and the market collapses. |
| Scientists and engineers use the terms positive feedback and negative
feedback in the design of control systems. Generally speaking, people
give each other support and encouragement by providing positive feedback.
Positive feedback reinforces a particular action or behaviour and encourages
one to keep on doing more of the same thing. This creates a multiplier effect.
Sometimes this can be a good thing. Other times it can be detrimental, what
we commonly refer to as the "vicious cycle". In population
growth, such as in the mating of rabbits or in a nuclear reaction, the number
of rabbits or neutrons keeps on multiplying at every next generation. Positive
feedback creates a run-away situation and overshoot.
The proper design of control systems requires the application of negative feedback. This is not to be confused with giving "bad vibes". It is the means by which the controller can suppress the growth of the population and attain a steady state. Too much negative feedback causes the population to crash. In the case of a nuclear reactor, this is a very delicate balancing act not unlike trying to balance a needle on its end. In human population decline, negative feedback will take effect in the form of pollution, environmental destruction, scarcity of food, water and medicine, pandemics and war. An important parameter in the design of a control system is the time lag or delay before any change, positive or negative, starts to have a significant impact. We must also include the time it takes for people to start noticing the effects. As with global warming and climate change, this time lag may be decades or centuries by which time it could be too late to do anything to prevent overshoot and crash. (When the positive forces overwhelm the counter suppressing forces we reach and surpass the "tipping point" also known as threshold, point of no return, run-away, melt-down, or whatever you would like to call it.) When applied to macroeconomics we can understand how time lag
presents a serious problem to the effectiveness of monetary or fiscal
policy. By the time government finance, budgets and policies are enacted
with the intent of tackling unemployment, inflation, recession or stagflagation,
the situation may already have changed. Rather than smoothing out the
bumpy ride of the economy, delayed monetary policies in fact tend to amplify
the oscillations. |
Once we can appreciate and accept that human population is limited by the carrying
capacity of the earth, growth can no longer be seen as being acceptable.
Zero growth in population follows and as a consequence so does zero economic
growth. We have entrenched in our views of economics that growth is essential
and a good thing. We have come to accept and expect growth in the economy, revenue,
profits and markets. We constantly hear repeated calls for more and more expansion
in commercial, industrial, municipal and urban developments. The word "growth"
has very positive connotations. Meanwhile economists give zero growth a bad
rap. They give it names such as recession, depression and stagnation.
Sustainability, by definition, is founded on the principle of zero growth. A mature system such as our society must and will reach a steady-state condition. At that stage the number of births will equal the number of deaths. We can no longer seek ever expanding markets, increasing revenues or an increasing tax base. Communities and municipalities must stop expanding. Our roadways and highways are overloaded. Waste dumps and landfill sites are full. The air we breathe and the water we drink are becoming more and more polluted. For society as a whole, the returns on our investments have reached negative territory. Growth has to end now.
How do we achieve a steady-state economy? Zero growth has to be accepted as the norm. There will not doubt be some hardships in getting there. Would we rather have short term gain for long term pain or the better choice, short term pain for long term gain? Unemployment could possibly rise but this does not have to be the case. If we can see the real benefits of mutual provision, unemployment would be replaced with job sharing and a shorter work week. When we see the damaging effects of our addiction for more material things, hopefully we will come to recognize the true value and capabilities of the human mind, body and spirit. We will seek a renewed connection with our fellow kind and learn the true meaning of mutual provision. We will learn to share our physical, intellectual and artistic talents and develop a keener appreciation for the arts, nature and the truely good things that life can bring.
Highway analogyWhile driving home on a long holiday weekend I was caught in stop and go traffic on the highways. With so many cars on the highway these days every motorist has experienced traffic slowdowns that occur for no apparent reason. These traffic snags appear to propagate in waves for many kilometres and can extend for hours. While crawling along at a snail's pace I came upon this simple solution to prevent this from happening in the first place and to get traffic up to speed as smoothly as possible. All it would take is for all drivers to follow this simple rule. Do not drive faster that the vehicle ahead of you. Contrary to what people might think, it is not slow vehicles that cause traffic slowdowns but faster ones. A faster vehicle sends the wrong message to every vehicle following behind. When the fast moving vehicle hits a snag, everyone following has to slowdown and this causes traffic throughput to come to a grinding halt. Self-serving interests such as driving faster in order to get ahead of everyone else is non-sustainable. Sooner or later you hit a limit and traffic flow comes crashing down for everyone as a whole. By driving no faster than the vehicle ahead of you on congested highways you don't have to hit the brakes. Vehicles would maintain a smooth flow and traffic flow would eventually pick up speed. We agree with and support Community Solutions' slogan - Curtailment & Community, that is, we stop the destruction of our environment and we build resilient communities instead. In order to make this world a better place to live in we need to remind ourselves of these two things. Let us all slowdown and learn to watch out for each other rather than pursue our own self interests
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