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

Introduction
This section is concerned with one of the most important challenges to face the teacher of
physics - that presented by the ‘Energy Problem’. To the teacher this problem has two aspects:
the first is global, concerned with supply and demand, with resource and reserve, with ‘have’
and ‘have not’; the second is internal to physics education and concerned with relevant teaching
and learning.
Physics teachers can no longer hope to restrict their attention to the purely teaching problem
and the traditional logical approach to it. That way required us to start with a force (which
children found relatively easy to understand because they could feel forces), and then to define
a parameter strangely called ‘work’ and finally to introduce energy through some such definition
as ‘the ability to do work’. To many young minds, this traditional approach is so remote from the
world in which they live that they decide that the whole business (and physics too) is quite
irrelevant.
Regrettably these young people are right in perceiving that a study of energy based solely on
such a formalized approach makes very little contribution to their understanding of the world’s
energy problem. It may even be a hindrance to the man or woman in the street who tries to
understand what he or she reads about energy in the press.
For example, one observes that the word ‘conservation’- which is now so very fashionable -
means something quite different to the politician from what it means to the careful user of
English in general and to the scientist in particular. To the politician and, as a result of intensive
propaganda, to the man-in-the-street, the ‘conservation of energy’ has come to mean nothing
more than the ‘saving of energy’. Advertisers wil say that if I eliminate some of the energy losses
in my home or my factory, I shall ‘conserve’ energy. They mean that I shall ‘save energy’. To
others the word conservation implies ‘preservation’; we may wish to assist in ‘the conservation of
the countryside’ or ‘the conservation of an endangered species’. That is a legitimate use of the
word. To the scientist, the word conjures up the image of the great conservation laws, the thought
that energy is neither created nor destroyed as it is transformed from one form to another. If we
are familiar with its limitations, that is a very useful statement. If we are not so familiar it may
even appear to suggest that the ‘problem’ does not exist! Our students deserve to be alerted to
such a difference in meaning.
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