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

New Trends in Physics Teaching IV
topics discussed were oil, hydroelectric power, nuclear energy, solar energy, research in solar
energy, bioconversion, geothermal energy, wind power, energy from the sea, etc.
At the formal level the present author has prepared a module on Momentum and Energy
addressed to the secondary and senior secondary teachers. Out of 136 pages, 88 are devoted to
energy. The topics dealt with at length are energy conservation, energy requirements, nonrenewable
and renewable sources of energy, solar energy and fusion energy.
For example, under energy requirements, attention is drawn to the fact that our (world)
energy requirements are growing at a fantastic rate. The estimated energy consumption between
1870 to 1970 A.D. was about half of the total from 1 A.D. to 1870 A.D. The requirement during
the next century is expected to rise by a factor of 25 of that during the last century. So there is
a need to search for new sources of energy that can sustain the growing demands on energy.
Under non-renewable sources of energy the attention is focused on the energy crisis that the
world is likely to face in view of the threat that petroleum and coal reserves are not likely to
last long, the conservative estimates being next 50 years (i.e. 2030 A.D.) for petroleum and next
100 years (i.e. 2080 A.D.) for coal. The possibility of averting the crisis lies only in economizing on
fuel consumption, utilizing and exploring the renewable or alternate sources of energy such as
solar energy and energy from bio-wastes. The efforts of Petroleum Conservation Research Association
(PCRA) have highlighted that by careful use, even a 5 per cent saving on petrol may result
in an annual national saving of about 200 crores of rupees (about 250 million U.S. dollars) at
present prices.
As mentioned earlier, in the school textbooks produced at the national level (i.e. by NCERT)
as well as at the State level, energy has not been used as an integrating factor. However, in the
latest editions, the relevance of energy to different aspects of life has been emphasized in different
classes at suitable places. If a 16- or 18-year-old student who has passed class X or XI1 tries
to recall everything he has been taught about energy, he is likely to arrive at some integrated
picture about the problems relating to energy; otherwise the picture is a very disjointed one. For
example, the concern about the growing energy demands and limited energy resources has found
its place in Environmental Studies Part II, a textbook for class IV which teaches pupils that we
need energy to do work and to move fans and machines and that different objects get their
energy from different sources, e.g. muscular, mechanical, electrical etc. In Learning Science Part I
for class VI, the students learn that the sun is the main source of energy on the earth, that almost
all sources of energy on earth are due to the sun, that man’s energy requirements are increasing
and that present sources of energy are likely to run out. The amount of natural fuel available
on earth is limited and therefore economy must be practised in the use of energy in daily life.
Students are also taught that there are different forms of energy and that one form can be converted
into another.
In Learning Science Part 11 for class VIII, the quantitative aspects of energy, and particularly
of electrical energy, are dealt with in detail. The concept of nuclear energy as an alternative
source is also introduced.
In Science Part I for class IX, the concept that there are different sources of energy (the sun,
fossil fuels, biogas or gobargas) is again emphasized. In Science Part 11 for class X, the quantitative
aspects of electrical and chemical energy are dealt with in greater detail.
In Physics for classes XI and XII, the quantitative aspects of mechanical, electrical and nuclear
energy are dealt with in greater depth. The law of conservation of energy is introduced through
the First Law of Thermodynamics.
Lastly, special efforts are being made to introduce the concepts of energy at the primary stage,
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