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

New Trends in Physics Teaching IV
encouraged nuclear physics almost to the exclusion of other topics, and his disciples fi1lX.d
many of the important chairs of physics. This, together with the exciting developments in Low
Temperature physics and the growing interest in the Solid State physics, became the dominant
topic and optics was almost squeezed out.
In actual fact, a great deal was going on between the wars that we should now recognize as
optics. The Braggs were developing the art of X-ray crystallography; ultra-violet and infra-red
spectroscopy were beinp developed; the seeds of radar and of radio astronomy were being sown.
But these were scattered topics; they did not have much influence on teaching in Universities
and Schools and they would not have been included in a conventional optics course. I would
contend therefore that, although optics appeared to be lost, it would be better to describe it as
dormant or eclipsed.
THE RESURGENCE OF OPTICS
It is always difficult to pin-point the crucial ideas or experiments in the evolution of a subject
until long afterwards when, with hindsight, one can begin to see the whole path of development.
But it seems clear to me that the resurgence of optics as one of the dominant fields of
physics began round about 1950.
Many factors began to come together in the period 1950 to 1970 which can be seen either as
a complete revolution - or, as I prefer to think of it - as a re-recognition of the excitement and
significance of the much earlier discoveries, a taking-up of the story that was set on one side in
the thirties and forties. The factors that came together were the development of radar to the
point at which it became not merely ‘radio-direction and range’ but an imaging system; the
development of television systems which play an important role in imaging by most radiations;
the development of digital computers which permitted the computation and design of lenses with
a performance beyond the dreams of opticians of even thirty years ago; the practical realization
of stimulated emission in lasers; the vast financial expenditure on the space programme which
needed highly developed image processing techniques; advances in solid-state physics for detecting
radiations of all kinds; and, perhaps most important of all, a full recognition of the importance
of information processing, information exchange and the key ideas of band-width limitation.
This, in turn, led to the search for ever higher frequencies for communication, culminating in the
modern use of optical fibres and laser light which certainly wil be a general method of communication
by the end of the century.
SHOULD NOT MODERN OPTICS BE REGAINED AS A SIGNIFICANT COMPONENT IN THE
PHYSICS SYLLABUS?
I am quite convinced that it is high time that optics was put back as one of the dominant features
of the physics syllabus in both schools and Universities. The potential is enormous and it fills so
many of the desirable criteria for a course which can be both intellectually demanding and at
the same time put over to the less able students through exciting and dramatic demonstrations.
In the first place, I think that it is of paramount importance that everyone should know and
appreciate something about the way in which we gain information about the world around us.
The eye-brain system is one of our principal channels for collecting, sorting, remembering and
using information, and a proper understanding of its potential and of its limitations is important.
One of the advantages of basing a course on this kind of topic is that it has obvious appeal to all
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