Environmental Engineering Reference
In-Depth Information
transformation and its quantitative conservation it makes
possible a measurable relation between all domains of nat-
ural phenomena. Its exclusive right to rank along space
and time is founded on the fact that, besides energy, no
other general concept finds application in all domains of
science. Whereas we look upon time as unconditionally
flowing and space as unconditionally at rest, we find en-
ergy appearing in both states. In the last analysis everything
that happens is nothing but changes in energy. (Translated
in Lindsay 1976, 339)
successive mastery and control over sources of energy
ever nearer the original source'' (1926, 48). The twen-
tieth century brought a fundamental extension of the
first law of thermodynamics with Albert Einstein's (fig.
1.4) follow-up of his famous relativity paper (Einstein
1905). Soon after its publication Einstein, writing to a
friend, noted, ''The principle of relativity in conjunction
with Maxwell's fundamental equations requires that
the mass of a body is a direct measure of its energy
content—that light transfers mass'' (cited in A. I. Miller
1981, 353). During the next two years Einstein formal-
ized this ''amusing and attractive thought'' in a series of
papers firmly establishing the equivalence of mass and
energy.
In the last of these papers he described a system behav-
ing like a material point with mass,
The contrast between the rising demand for coal and
the inexorable thermodynamic losses during coal's con-
version led first to greatly exaggerated fears about the
fuel's exhaustion (Jevons 1865) and eventually to rea-
soned arguments in favor of energy conservation. Ost-
wald's energetic imperative—Waste no energy but value
it—is relevant as humankind makes the inevitable transi-
tion to a permanent economy based exclusively on solar
radiation. Another Nobel laureate, Frederick Soddy (fig.
1.4), was the first scientist to make the analogy between
utilizing natural energy flows and relying on fossil fuels:
''The one is like spending the interest on a legacy, and
the other is like spending the legacy itself.'' He also
anticipated ''a period of reflection in which awkward
interviews between civilization and its banker are in pros-
pect'' (Soddy 1912, 139). Concerns about the necessity
to start living again on the interest were rekindled with
recent forecasts of the imminent peaking of global crude
oil extraction (C. J. Campbell 1997; Deffeyes 2001).
After World War I, Soddy looked closer at the relation
between energy, evolution, economics, and human pros-
pects, and he generalized the links by observing, ''From
the energetic standpoint progress may be regarded as a
M
¼
m
þ
E
0
c
2
;
and noted that this ''result is of extraordinary theoretical
importance because a physical system's inertial mass and
energy content appear to be the same thing. An inertial
mass m is equivalent with an energy content mc
2
'' (Ein-
stein 1907, 464). The world's most famous equation
requires any mass releasing energy to diminish, a fact of
no practical importance in chemical reactions. For exam-
ple, the combustion of 1 kg of hard coal (requiring 3 kg
of O
2
and releasing@30 MJ of energy) will diminish the
mass of the two reactants by about 10
10
, a reduction
too small to measure. In contrast, in nuclear reactions
the reduction is obvious. Einstein, aware of this differ-
ence, noted that a practical demonstration of the law
was difficult but that for radioactive decay the quantity
