The topic is
ordered in a fashion which presents a narrative which echoes the historical
development of our understanding of the universe. This makes good sense since students start by
learning about the apparently simple things that they can see around them and
progress to considering more distant bodies in space and eventually more
abstract physical phenomena. The structure
of the curriculum also plays to young children s natural curiosity about the
world around them. This enables students
to engage in a meaningful way with the topic at a young age, preparing them to
learn about more complex phenomena at later stages. For example many children will have noticed
the Sun s apparently changing position in the sky and studying this at KS2
allows for continuity when thinking about the astronomical meaning of a day
at KS3. Using the
Piagetian model of development, pupils at KS1,2 and possibly early stages of
KS3 (Year 7) are at the concrete operational stage (Pulaski, 1980) and can
engage with things they have experienced (such as the rising and setting of the
Sun or phases of the Moon). At later KS3
(Year 9) and KS4, pupils are capable of reaching the formal operational stage
and can reason logically about abstract concepts (eg: Gravity as a force
between massive objects). Although
studies have since shown that there is greater flexibility in developmental
levels than initially assumed by Piaget (Donaldson 1978, cited in Levinson,
2005), pupils must reach earlier levels before progressing onto higher levels
and as such the curriculum is, broadly speaking, well laid out to support
progression in this topic. The curriculum
progresses knowledge and understanding about the Universe along two main
threads, one (starting at KS1) which looks at the working of the solar system
and the Newtonian mechanics that explain the motion of bodies in a system like
the solar system (a sort of local astrophysics ), the second (starting at KS4)
looks beyond the universe to take in cosmological considerations about the
fate, origin and nature of the universe as a whole. Teaching
students (at KS2) that objects fall downwards because of the attraction between
them and the Earth seems to conflict with teaching that the Earth is roughly
spherical. One would imagine that good
teachers would scaffold against this possible disparity by explaining that
wherever one is on the Earth s surface, down is the direction towards the
centre of the Earth. Studies (Nussbaum Novak, 1976, Nussbaum, 1979,
Mali Howe, 1979, Sneider Pulos, 1983 cited in Nussbaum, 1985),
however show that many children hold misconceptions about gravity and the earth,
often born out of their attempts to reconcile what they can see (flat earth,
dome-like sky, objects fall down perpendicular to earth) with what they are
taught (Spheroid earth, sky is phenomenon of atmosphere, objects drawn by
gravitational attraction towards centre of the earth). Many misconceptions
involve an objective gravitational down independent of the earth. [Citation].
Since the concept of a planet s gravity acting radially is not
explicitly introduced until year 9, any misconception developed at this stage
may well be fully ingrained into students thinking by the time it is
challenged by their teachers. Amending the KS2 syllabus to state explicitly
that gravity on earth is directed towards its centre or perhaps moving some KS3
work relating to gravity to Year 7 to provide greater continuity would at least
avoid unintentionally fuelling some popular misconceptions about the Earth and
its gravity. Indeed, a study
by Nussbaum and Sharoni-Dagan (1983, cited Nussbaum, 1985) showed that of a
group of eight year-olds who were taught a more scientific explanation of the
nature of the Earth and its gravity, significantly more gave an accepted
scientific account of these phenomena, compared with classes of their peers who
did not receive such instruction: i.e. at least a significant portion of this
class were capable of understanding phenomena that the current curriculum plan
suggests are more suited to older students. Students hold
many other misconceptions about gravity including that it does not work in
space and that it increases with height above the Earth s surface(Stead
Osborne 1980, Ruggiero et al 1985, Watts Gilbert 1985, cited in Driver,
et al, 1994). Since a basic
understanding of gravity is essential for almost all of the concepts covered on
the Universe, from planetary orbits to the formation of stars and even
cosmological considerations, it would be useful to establish earlier the
concept of gravity as a force. Since force
is an abstract concept, explaining states of equilibrium and non-equilibrium,
the Piagetian model suggests that it is beyond the grasp of pupils at KS2. However, the concept of a force is introduced,
in terms of contact forces like pushes and pulls, even at KS1 and invisible
non-contact forces are introduced at KS2 through work with magnets, something
that, in my experience, children of all ages enjoy and find particularly
stimulating. At Gunnersbury,
from Year 9 (KS3) onwards, pupils experience a joined-up progression in
learning Newtonian ideas in astrophysics only if they sit separate sciences at
GCSE. Students who take GCSE Science and
Additional Science and then take Physics at A Level study these ideas only
sporadically before encountering the more challenging calculations required at
A Level. This is due to the substantive
focus of the Y7 KS3 Syllabus and the focus of AQA GCSE Science on
Cosmology. It should be noted that the
concepts relating to the Universe covered by this programme in these key years
(first year of secondary school, first year of GCSE) are, in my experience, topics
which students ask the most questions of anything in physics, so probably have
been chosen with a view to capturing interest, which is certainly important in
education. However, Edexcel covers most
KS4 astrophysics and cosmology units in GCSE Science, giving greater continuity
into KS5 whether students take two or three GCSEs in science (Edexcel, 2007). By contrast,
the units on cosmological considerations show good continuity and a clear
progression from AQA GCSE to Edexcel A-Level.
For example students must progress from knowing what nuclear fusion is
to describing the process in some detail.
