It is interesting that text book items are quoted without
attempting to provide a sound contrary argument to the assertion that the
systems of civilization are irreversibly using up limited natural material
capital and producing material wastes. This assertion does not appear in text
books because it is an innovative way of looking at the fundamental principles
of what invariably happens. Leaving aside the controversial radiation (a
process in which energetic particles or energetic waves travel through a
vacuum) of the solar energy from the Sun, some of this incident solar energy is
transformed to heat energy in air in the atmosphere. The consequences are winds
(kinetic energy of air) and numerous other operations that are taken for
granted. Some of the incident solar energy is used to produce chemical energy
(carbohydrates) in plants (made of materials that grow and then decay). Some of
this solar energy is absorbed in the oceans so affect the currents that have
such an impact on other operations. Some of this solar energy is now absorbed
in solar panels where it is converted to electrical energy.
A discussion of what happens in operations
(processes) should also consider what happens over time to the system (made of
materials) in which the process takes place. The nature of the process depends
on the state of the system. If the system does not exist then the process
cannot occur. There is a vast amount of heat energy in the oceans and this has
an influence on many natural operations, such as currents. But only a very few
technological systems have been installed to convert a very small proportion of
that heat energy to electrical energy. All existing systems age due to the
action of natural forces, including friction. So the nature of the processes
carried out in an aging system adapts to the changing environment of the
operation. The power of a petrol engine declines over time as many of its components wear.
The mathematical equation for energy =
force x distance is often quoted as underpinning the process. Energy is transformed when it
flows to do work. That is reality is embodied in the mathematical definition of work. Stored energy,
such as the bond energy of chemical compounds, do not do work. So processes
always involve the "flow of energy" and any discussion that just uses
the short hand term "energy" presumes, unwisely, that the qualification
is understood. That work statement is a well-recognized fundamental principle
but it relates to only those circumstances where the energy associated with the
material has the potential to do work by flowing, either spontaneously or when
activated. That energy equation above has no relevance in energy transformation
but other (thermodynamic or fluid dynamic) equations underpin these
transformation processes. But all processes involve the irreversible flow of
energy through a
system made of materials. Some mathematical equations deal with aspects of
the nature of the operation (process) but often they have to have allowance for
real effects such as friction.
Some
processes that have a stage which entails the transformation of energy to do
work do not have an associated transformation of material. A generator does
work in transforming mechanical (kinetic) energy into electrical energy with a
high efficiency as only a small amount of that kinetic energy is dissipated as
heat energy due to friction. The material lost in the bearings due to this wear
is a long term problem for the maintenance people and those who have to pay for
this dose of reality. But the generator is not transforming material in the
process. Heat energy does the work to provide kinetic energy in gas turbines
without a material transformation. Pressure energy does the work to provide
kinetic energy in water turbines without a material transformation. The
filament in a light bulb transforms electrical energy into visible light
energy (and some heat energy) without transformation of the filament material
although the filament will slowly degrade.
On the
other hand, as is now well known, the coal combustion work process transforms
chemical energy in the coal to heat energy and transforms the material (mainly
carbon) into gaseous, vapor and particulate wastes. The process of
transforming (refining process) iron ore to metallic iron through the work done
by the flow of the energy input produces vast amounts of waste heat. Both
energy and materials are transformed in both of these processes. All natural
processes also have the dual (energy and material) transformation process. The
functioning (metabolism) of the human body is a classic example.
So it is
only in some technological systems that the flow of energy to do work entails
only the transformation of the energy. Most of the processes in these systems
entail the transformation of both energy and materials. Ironically this
significant difference between the operation of processes in technology systems
is not covered in engineering courses at universities. Thermodynamics and fluid
dynamics cover the irreversible flow of energy (increasing entropy - Second Law
of Thermodynamics) in doing work in the operation of technological systems.
Chemistry covers the transformation of chemical compounds (material) due to the
flow of energy in (endothermic) or out (exothermic) of the reactions. Physics
embraces the impact of numerous natural laws including the conservation of mass
(of materials) on the operation of physical systems without taking into account
that mass is transformed into waste in the aging process and often in the work
process. Other subjects cover what happens (such and stresses and strains) to
materials in operations.
The
fundamental operational principles enunciated here are governing what is
happening in current operations even though most people do not understand the
nature of this irreversible process. The technological infrastructure hosting
this unsustainable process is already degrading the life support system. Future
widespread improved understanding of these fundamental principles can only lead
to smarter decisions about how to power down.
Denis
Frith
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