Energetics is the study of the transformation of energy. It encompasses thermodynamics, chemistry, biological energetics, biochemistry and ecological energetics. It also describes the useful and non-useful tendencies of energy flows and storages under transformation.
The origin of Energetics still remains unknown today, with different theories:
· found in the work of the ancient Greeks
· mathematical formalization began with the work of Leibniz
· Rankine formulated the Science of Energetics in his paper Outlines of the Science of Energetics published in the Proceedings of the Philosophical Society of Glasgow in 1855
· atomic view of the atom forwarded by Boltzmann's gas theory
· Lotka proposed that the selective principle of evolution was one which favoured the maximum useful energy flow transformation, which influenced the development of ecological energy
Liet.-Col. Richard de Villamil (1928) said that W. Ostwald and E. Mach subsequently developed the study and in the late 1800s energetics was understood to be incompatible with the. Proof of the atom settled the dispute but not without significant damage. In the 1920s Lotka then attempted to build on.This view subsequently influenced the further development of ecological energetics, especially the work of Howard T. Odum.
De Villamil contrived a system that divides mechanics into two branches: energetics (the science of energy) and "pure", "abstract" or "rigid" dynamics (the science of momentum ). The dimensions for dynamics are space, time and mass, and for energetics, length, time and mass.
Thermodynamics is the movement of energy. It is defined by laws which serve as the basis for many biological concepts. These laws dictate how energy can be transported, which of course can be applied to ecology because energy transfer is what drives metabolism and, on a larger scale, food chains and food webs.
The principles of energetics are as follows:
- Zeroth principle of energetics
If systems A and B are in thermal balance, and B and C are also in thermal balance, then A and C are in thermal equilibrium balance.
- First principle of energetics
increase in the internal energy = energy added to system by heating- amount lost in form of work
- Second principle of energetics
Any isolated thermodynamic system tends to increase the total entropy over time, reaching a maximum value.
- Third principle of energetics
all processes cease and the entropy of the system approaches a minimum value if the system reaches absolute zero of temperature
- Fourth principle of energetics
Two opinions:
- Onsager reciprocal relations - as the fourth law of thermodynamics, it would constitute the fourth principle of energetics.
- H.T. Odum’s Maximum power- Odum proposed the Maximum empower principle as a corollary of the maximum power principle.
- Fifth principle of energetics
Hierarchically increasing is the energy quality factor. Hierarchical webs develop flows of energy and maximize the power of the system
- Sixth principle of energetics
The energy/mass ratio measures the material cycles that has hierarchical patterns and determines its zone and pulse frequency in the energy hierarchy
Energy is applied to ecology through its entry and release in the ecosystem. Some energy is lost as heat re-enters the system to maximize the energy use. Plants (producers), animals (consumers), detritivores and other organisms depend on the energy transferred or transformed from one trophic level to another. Energy transfer is what drives metabolism and, sometimes food chains and food webs.
Energy enters the ecosystem through photosynthesis, which transforms solar energy into chemical energy transformed and stored by plants (primary production). The energy is then transferred to herbivores (secondary production). The activities and processes done by the consumer consume the energy and others are lost in the form of heat. The next trophic levels stay the same, until the decomposers feed on the energy left. The heat energy that is lost then re-enters the ecosystem.
An Ecological Pyramid (or Trophic pyramid) is a graphical representation designed to show the relationship between energy and trophic levels of a given ecosystem. Most commonly, this relationship is demonstrated through the number of individuals at a given trophic level, the amount of biomass at a given trophic level, or the amount of energy at a given trophic level. It is worth noting that all Ecological Pyramids begin with producers on the bottom and proceed through the various trophic levels, the highest of which is on top. (Above is an image of an Ecological Pyramid).
There are two types of Ecological Pyramids that exist:
Pyramid of Biomass shows the relationship between energy and trophic level by quantifying the amount of biomass present at each trophic level (dry mass per trophic level).
Pyramid of Energy shows the direct relationship between energy and trophic level. It measures the number of calories per trophic level. As with the other, this graph begins with producers and ends with a higher trophic level.
A Biogeochemical cycle is an organic cycle is a circulating or repeatable pathway by which either a chemical element or a molecule moves through both biotic (“bio-”) or abiotic ("geo-") compartments of an ecosystem. In effect, an element is chemically recycled, although in some cycles there may be places (called "sinks") where the element accumulates and is held for a long period of time. Important biogeochemical cycles are Hydrologic cycle (Water Cycle), Carbon cycle, Nitrogen cycle and Phosphorus cycle
Specific applications of the concepts mentioned above are as follows:
a. Energetics
- Computations of Calorie Transfer
- Utilization of Plants as Food
b. Thermodynamics
- Calculations of Energy Transfer in Food Chains/Webs
- Improvement of the Stability of a Community in an Ecosystem
c. Ecological Pyramids
- Measurement of Biomass in each Trophic Level
d. Biogeochemical Cycles
- Regulation of the Amount of Needed Chemicals Present in the Environment
WHAT HAVE WE DONE SO FAR?
Exit your house and walk on the road for a bit. Eventually a car will pass by emitting gray gas. This gas is one of the factors that disrupts the carbon cycle. Accumulations of gases such as these cause one of the world’s biggest problems today, Global Warming.
Think of a filter, with sand passing through it. A small quantity of sand takes only a small time in passing through the filter, while a large quantity, in opposite, takes a long time to pass. Sooner or later the sand would accumulate and the time it takes to filter all the sand will become longer. This is what’s happening to the carbon cycle today, with the atmosphere as the filter and carbon as the sand. When the carbon piles up in the atmosphere, the cycle is disrupted and phenomena like global warming (piling up of gases in the atmosphere causing holes in the ozone which provides way for too much sunlight and heat) results.
Global warming is worsening each day and we can largely feel its effects on us and on the environment. Our climate has changed from stable to unpredictable during the last years. I remember this one conversation I had with my late father when we were taking a stroll in the campus of UPLB (this was the time when I was still a college student in UPLB) I was complaining about how hot the weather was, and that if I did not get into a shade soon I would get sunburns all over my arms and face. To this he replied in a did you know that tone that when he was young, no matter how many hours he stayed outside to play or take a walk he did not feel uncomfortable in any way with the heat. He told me how lucky he was that he been born in his time and not in the recent years where Global warming is coming to extremes. I was amused as to how the world can change so immensely in such a short time period.
I still remember when this experience with my son when he was still studying at Maquiling School Inc. We were coming home from school via a service jeepney one rainy day. Soon the vehicle came to a stop and we realized that we were already in front of our house. With an umbrella ready in hand, my son came out into the rain and walked towards our gate. While opening the gate a drop of rain fell onto his hand and he told me it felt strangely different against his skin. He let a few drops fall onto his hands again and decided that something was wrong with the rain, so coming in, he asked me about it. Being familiar with this phenomenon, I explained to him that what he had felt was acid rain and it was becoming common nowadays. I added that acid rain is the precipitation of a mixture of gases (air pollution) with clouds in the air.
Recently, my son has found out that the principal causes of acid rain are sulfur and nitrogen compounds from human sources, such as electricity generation , factories, and motor vehicles. Through these human sources, the normal amount of nitrogen in the air has doubled, causing a disruption in the nitrogen cycle. The disruption of the nitrogen cycle has contributed to acid rain among the other consequences that come.
He experienced acid rain again after a few days and after that he didn’t feel or let alone notice it anymore. May be my son had just gotten used to the acid rain or it really had stopped.
I realize also that many anthropogenic activities can affect the operation of the different biogeochemical cycles. Some of these are the following:
- · Trees and Plant Degradation- the simple plant destruction anybody does add up to a big change. Every plant that is not replaced in any way counts. If ever more trees are present, the carbon dioxide present in atmosphere will be minimized
- · Burning Fuels- even though this process has temporary benefits to man, it breaks down the nitrogen molecules present in the atmosphere, sustainably breaking the nitrogen cycle within a place.
- · Land-use change- This technique used in vegetation may be harmful. This adds up to the carbon dioxide in the atmosphere.
- · Fertilizers/ Vegetation plus Soils- This mechanism takes up more carbon needed in the atmosphere. In return, less is given back by this.
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