Environmental Engineering Reference
In-Depth Information
basic variables and general approaches used in these
inquiries.
The first isolated brushstrokes of this vast canvas were
put down long before those decades of astonishing intel-
lectual ferment at the close of eighteenth century. The
word energy is, as so many of our abstract terms, a Greek
compound. Aristotle left its first known written record in
his Metaphysics (D¨ring 1966). He gave it a primarily ki-
netic meaning by joining en (in) and ´rgon (ergon, work)
to form en
´
rgeia (energeia): ''The word 'actuality'
(energeia) which we connect with 'complete reality'
(entelechia), has, strictly speaking, been extended from
movements to other things; for actuality in the strict
sense is identified with movement.'' According to Aristo-
tle, every object's existence is maintained by energeia that
is related to the object's function.
But the word's etymology reveals as much as it hides.
For Greeks the word and its cognates filled a much larger
conceptual niche, qualitatively and figuratively, than does
its modern scientific counterpart. In Aristotle's Ethics,
energeia stands in opposition to mere disposition, hexis;
in his Rhetoric, it carries the vigor of the style. The verb
energein meant to be in action, implying ceaseless mo-
tion, work, production, change. The classical concept of
energeia was a philosophical generalization, an intuition
embracing the totality of transitory processes, the shift
from the potential to the actual. The perception was
clearly holistic and qualitative. These concepts remained
unrefined for nearly two millennia. Roman civilization,
Islam, dynastic China, and medieval Europe solved
ingeniously many everyday energetic challenges, and
their remarkably complex societies were energized not
only by humans and animals but increasingly also by
machines driven by water and wind (see chapter 7).
But there were few concurrent advances in systematic
understanding of energy because even many founders of
1.1 Evolution of Energetics: From Aristotle to
Einstein
Energetics has no rivals in its interdisciplinary nature and
reach, a reality reflecting not only the vastness of the
potential subject matter but also the inquisitiveness and
achievements of generations of scientists and engineers
who contributed to filling in so many intellectual blanks.
Studies of energy phenomena have always proceeded
within many disciplines, sometimes in isolation, often in
parallel, later with profitable transfers and fusing ideas,
and since the mid-nineteenth century with increasingly
frequent attempts at finding general patterns and offering
grand syntheses from perspectives as diverse as physics
and historical economy.
Many outstanding creators of classical and modern
science were students of energetics. But this fundamental
yet inherently diffuse field of inquiry—spanning not only
physical, life, and social sciences but also many branches
of engineering and management—has never acquired
the much clearer identity of many reductionist disci-
plines, so their contributions have rarely been seen as
constituent pieces of an impressive mosaic that has been
assembled since the end of the seventeenth century. The
basic course of this intellectual progress is chronicled in
Mach (1896), Stallo (1900), Brody (1945), Cardwell
(1971), Lindsay (1975), Martinez-Alier (1987), and C.
Smith (1999). I offer just a brief account of advances in
formulating the most fundamental explanations, includ-
ing the laws of thermodynamics, the nature of metabo-
lism, and the place of energy in economic advancement
and civilization's survival.
