New trends in physics teaching, v.4; The ... - unesdoc - Unesco

New Trends in Physics Teaching IV
Energy and energy degradation as complementary aspects
of energy processes and a stepwise introduction to the
concept of energy
H. SCHLICHTING.
One reflection of the permanent public interest in problems concerning energy is the renaissance
of interest in the concept of energy in science teaching. New school books devote more space
to energy than their predecessors and the number of articles about energy in journals of science
teaching has increased.
However, the influence of the real problems of the scientific-technical world on the content of
science teaching is one-sided; there is little appreciation that the investigation of energy in school
would contribute to a better understanding of the world’s energy problems.
In our opinion this is largely due to two factors: first, the energy concept is generally taught
independently of its significance for everyday life, and, second, the topic of energy is reduced to
just one aspect - conservation. The consumption or down-grading aspect, although much more
important in everyday life, is given scant attention.
The first of these two factors refers to the current practice in school courses. Apart from a few
exceptions, mainly in English-speaking countries (e.g. Nuffield [ 1 1 energy is derived from
other mechanical quantities according to the scheme: force + work += energy. This implies that
the understanding of energy is intended to follow from an understanding of combinations of
quantities which are, by themselves, very difficult concepts. This detour via other quantities
renounces not only the possibility of starting from a common-sense understanding of energy
based on many familiar phenomena (see e.g. Schlichting and Backhaus [ 21 ) but even detracts
from any common-sense understanding that may develop. A confusion, injurious to understanding,
of two ideas about energy may result. Moreover, this academic treatment leads to
another conflict with everyday experience: energy is introduced as a conserved quantity and
pupils are taught that it may neither be created nor destroyed. In a physics lesson taught by the
author, a pupil asking how the existence of an energy crisis fits with the conservation of energy,
alludes to those experiences which have taken energy into the focus of social-political interest:
(1) Man’s energy supply has become uncertain because (2) the conventional energy resources are
being steadily depleted. (3) Alternative resources are being sought and, (4) on all sides, people
are asked to save energy and to be ‘energy conscious’.
Furthermore, the experience of pupils in which the fuel tanks of cars and trucks become
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