A modern interpretation and generalization of the second law of thermodynamics.

A deeper understanding of the second law of thermodynamics has helped me gain a deeper understanding of the world we live in. It is something I want to share.

The first image taken by humans of the whole Earth. AS8–16–2593. William Anders, Apollo 8.

The second law of thermodynamics

The second law of thermodynamics knows many definitions and descriptions. We can understand the law as follows:

“In a closed system, all macroscopic phenomena are temporary, as they tend to decay, flow from high concentrations to low concentrations, until maximum entropy is reached at equilibrium, after which all observable phenomena are gone. The level of even distribution is defined by a measure called the entropy. The entropy of a closed system will increase until it reaches a maximum value, the value at equilibrium.”

Loosely speaking, things tend to decay, break and spread. This phenomena explains why hot coffee cools down, why mixed colors of paint stay mixed, and why cars break down.

The observation is easy to demonstrate. A simple computer simulation and visualization of many small bouncing balls on a screen proves the point. Whatever the starting points of the balls, from a zoomed-out view, the balls will distribute and spread across the available space, progressing towards an even distribution of bouncing balls. The phenomena is so obvious and common sense to us, that one may wonder why it is worth stating at all.

This law was discovered to be universal in the 19th century, in describing the theoretical maximum efficiency of steam engines. Great minds of the 19th and 20th century found this simple law to have many meanings, interpretations and expressions, beyond the realm of just heat and work.

“The law that entropy always increases holds, I think, the supreme position among the laws of Nature. […] if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.” Sir Arthur Stanley Eddington, The Nature of the Physical World (1927)

The law is visibly true at all scales, right down to the microscopic. The sub-microscopic world is dominated by particle physics and chemistry. At this level the law stops making sense, because at this level one cannot speak of macroscopic phenomena. At all levels above the sub-microscopic, the law of increasing entropy dominates our world.

The law is not specific to our universe. The law is a mathematical law that is true in all universes and simulations that have conserved matter and energy, and a common set of microstate rules. If one were to change the microstate rules of a simulation, one is effectively changing the mathematical shape of the progression of increasing entropy. All the while, entropy is never decreasing. The law is true for all closed systems in space, in all regions, at all locations, at all macroscopic sizes, at all periods of time, and at all time scales.

Macroscopic phenomena

The second law of thermodynamics describes a link between the sub-microscopic (the rules of particles/atoms/molecules) and all emergent macroscopic phenomena (everything we naturally observe). A macroscopic phenomenon can be anything naturally observable, such as shape, change or flow, or combinations thereof. In other words, any observable phenomenon that is non-sub-microscopic (everything we see around us, including yourself) is a macroscopic phenomenon.

The progression of all macroscopic phenomena can be understood as the local increasing and decreasing of entropy, while always holds true that there exists an enclosing closed system where total entropy is never decreasing. Macroscopic phenomena decay, and while doing so they cause a cascade of smaller macroscopic phenomena, and so on until all phenomena fade away. We can understand the increasing entropy of our universe as the driving force behind all emergent macroscopic phenomena in the universe. We live in the world of macroscopic phenomena, an emergent mathematical layer of reality. The law provides a prediction of future observation, a prediction of direction of change. For that reason some call it the arrow of time.

From the perspective of macroscopic phenomena (our world), many basic observations and patterns can be described. These observations are already implicit by the second law of thermodynamics, but it helps to list these observations separately, to construct an expressive set of laws.

Here follows an interpretation of the second law of thermodynamics from the perspective of macroscopic phenomena.

The laws / the observations

1. A macroscopic structure is any local region of any scale in the universe consisting of macroscopic concentrations (of whatever variable microstate measure) that differs from the macroscopic concentrations at equilibrium.

2. In a closed system, a macroscopic structure causes macroscopic change, which results in the decay of the macroscopic structure. The decay of macroscopic structure and change is synonymous with the increase in entropy.

3. High concentrations of microstates tend to flow to regions of low concentrations, if there exists an accessible path between those regions.

4. Macroscopic concentrations of energy flow to regions of lower concentrations. It is this macroscopic flow of energy that is useful to us. Although energy is conserved at the microstate level, macroscopic useful energy is not.

5. A macroscopic phenomenon can only sustain when fed with macroscopic phenomena from somewhere else.

6. Macroscopic phenomena cannot be created without destroying at least as much macroscopic phenomena somewhere else. All macroscopic phenomena are the result from the decay of earlier macroscopic phenomena. Macroscopic phenomena can be combined to form larger and more complex macroscopic phenomena, but always at the cost of waste macroscopic phenomena.

7. Temperature, the average kinetic energy of the particles, is directly connected with the second law of thermodynamics. Temperature has a direct impact on all macroscopic phenomena. Increasing temperature increases the rate of decay of all macroscopic phenomena.

Life as a macroscopic phenomena

While the sun shines its energy on our rotating planet, macroscopic phenomena emerge and accumulate, i.e. regions of lower entropy. These regions discipate their phenomena to regions of higher entropy, creating cascades of sub-phenomena. Somehow life has emerged in these accumulations and cascades. Life is a progression of evolution, which requires the process of replication. One would therefore think that life is only possible in universes that have microstate laws (laws of particle physics) that are expressive enough such that it’s chemistry holds a solution to build a replicator. We live in such a universe. We are living proof that this is so.

Life is a mathematical space where the expressive rules of the sub-microscopic meets the entropic rules of the macroscopic world. We can understand life as chemistry’s solution to deal with the over-accumulation of macroscopic phenomena. Life’s function is therefore to contribute to the decay of excess macroscopic phenomena, and to survive by feeding off it. Driven by enthalpy, heat and the entropic force, similar to a flame, life has the property of having the will to survive and grow, using whatever macroscopic phenomena the environment has to offer.

Being a macroscopic phenomenon

If life is a sustained macroscopic phenomenon, can the understanding of macroscopic phenomena provide us with a deeper understanding of ourselves? Here are a number of observations that describe our lives on our planet, from the perspective of macroscopic phenomena.

1. As can be observed, macroscopic phenomena come in various forms of macroscopic complexity:

Macroscopic structure

Macroscopic change

Macroscopic information

Macroscopic computation

Macroscopic communication

Macroscopic replication

Macroscopic intelligence

These are the building blocks of our macroscopic world, in increasing order of complexity and macroscopic cost. They can be transformed, combined, assembled, traded and transported, but always at the cost of macroscopic waste.

2. You are a macroscopic phenomenon with the macroscopic complexity of intelligence. You need macroscopic phenomena (such as food and water) and heat from your environment to survive.

3. One cannot create order without causing at least as much disorder somewhere else. Humans are masters at creating order on a large scale, at the cost of destroying at least as much order somewhere else.

4. Energy from the sun drives the constant influx of emerging macroscopic phenomena in our environment, from which life feeds. The total consumption of life is limited by the available macroscopic phenomena the environment has to offer. Spikes in population and consumption can temporary emerge when life feeds off accumulated reserves at a fast rate, but such empires inevitably collapse.

5. Humans are increasing the entropy of the environment at a much faster rate than is lowered by the sun. Fed by oil and coal, humans are mixing things up on a world wide scale, mining macroscopic concentrations of minerals found in the crust, producing temporary low entropy macroscopic concentrations of pure elements, breaking it down into small pieces, assembling and packaging these into gadgets, and spreading it across the planet. As these gadgets inevitably break down and become useless, we dispose of them as waste. Once the elements are embeded in gadgets, it becomes very difficult to reuse those elements (phones contain up to 64 different elements). Humans are the ultimate solution to increasing entropy at maximum rate, to accelarate the rate of decay and mixing up the environment.

6. Humans are causing the warming of the planet. Temperature is directly connected with the second law of thermodynamics. Therefore temperature has a direct impact on all macroscopic phenomena. Recent higher temperatures on earth has caused the destruction of many macroscopic cycles, killing many species that have become dependent on them. We can assume there exist temperatures for which there exist only disastrous solutions.

7. Humans have created an economy of accelerated growth, creating ever more complex useful products. Anything that can be regarded as useful is a macroscopic complexity, such as machines, cars and computers and phones. Mass production of macroscopic complexities come with the inevitable cost of consuming macroscopic phenomena from somewhere else, and producing waste and pollution as a byproduct.

8. Pollution is a destructive macroscopic phenomenon that is very difficult and costly/impossible to reverse. Pollution is a macroscopic anti-complexity.

9. Accelerated growth cannot continue indefinitely.

10. To dampen the impact of inevitable collapse, we must reduce growth now. Humans must define what is absolutely necessary and what is truly useful, to understand its impact on the environment, and understand the true cost of luxury. Ideally the price of things reflect its true macroscopic cost, which currently it does not.

11. The more new things we buy, the more is produced, and the more destruction we cause. To cause less destruction, we need to buy less new stuff.

The laws show that we cannot create a perpetual motion machine. Useful minerals are running out. We cannot keep producing and replacing solar panels forever. Unfortunately it does not look like we will have worldwide nuclear fusion reactors any time soon. Hopefully we can find some useful answers in chemistry, but it will not be enough. We have to change on a macroscopic scale, or it will happen anyway.

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