K4.4 The Earth and Beyond
The Earth and its place in the universe has been the subject of human speculation - and the basis of much cultural organisation and religion - since the dawn of civilisation. We have come to realise that Earth is not at the centre of the universe but its position as one satellite (planet) of the Sun (which itself is a modest star that is situated near the edge of the galaxy we call the Milky Way) is now accepted by a majority of people - although most still struggle with the relationship between the relative motions of the Earth and Sun in space and everyday experiences of day and night, the seasons, eclipses etc.. This article explores some of the barriers to understanding the scientific explanations of such commonplace experiences - and extends the range by considering the possible evolution of matter and the universe from the 'big bang'.
Consideration is given to some of the alternative conceptions held by learners and presentations are offered as downloads that may be adapted or used directly with trainee teachers. An expected progression of development of pupils' ideas from KS1 - 4 is explored. Practical experiences, models, simulations and some useful references and sources are provided.
This is one of 17 articles on www.scitutors.org.uk/ whose main aim is to support the processes of teaching/learning between the science education tutor and the trainee science teachers with a focus on “teachers’ knowledge and understanding”. During a primary or secondary BEd, PGCE or GTP we hope that those learning to become science teachers will be able to challenge their own understanding of science and scientific concepts. Unit K0 specifically explores general issues relating to all the knowledge units - to the learning of science.
Standards: This unit specifically addresses Q14 but, appropriately used can contribute to and provide evidence of competence for many others of the standards especially Q4,6,7,8,18, 22 and 25.
Keywords: Earth, Space, Day/Night, Seasons, Universe.
Human civilisations all have their stories about the origin of the earth and the heavenly bodies. Young children take it all very much for granted, but as they get older they also begin to ask questions and wonder what it's all about. Accurate astronomical observations have been made by ancient civilisations allowing them to build monuments such as the Pyramids of Egypt, the Americas and the far East, and stone circles such as at Stonehenge. From the time of Copernicus, Galileo and Newton (who re-established for the European Renaissance, the ancient belief that the Earth was not at the centre of the universe) it took another 4 centuries for our present scientific story to evolve. This story now begins with a 'big bang' which evolves into a universe made up of empty space peppered with galaxies of stars, where the elements of life were forged. Our own tiny planet, Earth, revolves round a small, recent star we know affectionately as the Sun, itself tucked away in an arm of a spiral galaxy we call the Milky Way.
We try to tell this scientific story to children and attempt to move them from their everyday experience of a flat solid Earth, to this universal view in just 10 years of schooling. (We, as teachers often have to do quite a lot of ‘moving’ ourselves too.) During their primary years we can tell the story as far as the solar system, but at secondary level they will discover space and time and distant galaxies, whose light may have set out on its way to us before the dinosaurs walked the earth, or even before our solar system came into being.
Download 2.0a contains a set of discussion questions that can be used with trainee teachers, both primary and secondary, followed by a discussion of the questions outlining some of the difficulties trainees may encounter in their subject knowledge. PowerPoint (download 2.0b) has a number of these questions in a format that can be used directly with trainee teachers.
Download K4.4_2.0a 'Ideas About Earth and Beyond'
Download K4.4_2.0b 'Ideas about Earth Power point'
In this section we outline some of the conceptual barriers to understanding ideas about the earth and beyond, and suggest how children’s ideas will develop through their time in school.
Gervinder has looked at the moon and the stars and the sun and learned about the solar system. He has read that much of this was first observed by the ancient Egyptians and Greeks. This confuses him for he has been told in his family that the stars, planets and their motion were first observed by early sages of his own religion. He is clearer about the shift in Western European culture from a geocentric to a heliocentric view of the solar system and the severity with which early proponents of the latter view were treated. He understands that life is often uncomfortable for those who challenge established views, within science and outside it, and he is prepared to discuss his own views with others such as his peers, his parents and his teachers. West (ed) (1984) page 44.
This is an extract “Gervinder” from the 1984 publication from the Secondary Science Curriculum Review, entitled “Towards the Specification of Minimum Entitlement: Brenda and Friends” (West, R. Ed. 1984, Schools Council Publication). Each topic on the curriculum was illustrated by the thoughts of a specific pupil having received a ‘minimum entitlement’ in science at school. It predates the National Curriculum and gives a much richer picture of what school science should be all about. The full section: “Gervinder – Space” is in download 3.0a
Download K4.4_3.0a 'Gervinder-Space'
What follows is an attempt to show how this understanding can grow as children progress through school. (For a fuller discussion of ‘adult-scientific’ understandings see download 2.2. Remember, however, that the scientific explanations are not ‘obvious’ or ‘common sense’. They require evidence to make them reasonable and convincing as well as considerable intellectual effort to understand and apply consistently. For example, much of the everyday language we all use implies that the Earth is flat and that the Sun moves around it. Also when considering models of our solar system it is often difficult to shift our viewpoint from looking at the whole model (seeing the Earth, Moon and planets – and their moons – relative to one another and the Sun) to visualising what things will look like from the surface of the Earth, from where all of our personal observations are made.)
Foundation Stage and Key Stage 1
Day and night - time Children have a range of ideas about the cause of day and night.Early ideas are linked with need - we need to sleep, we can rest at night.Simple explanations follow - the Sun swaps with the Moon, the Sun gets covered, the Sun sets. Some children will think that the Sun still shines somewhere during our night the Sun goes somewhere else.
An explanation depending on the spin of the Earth usually has to wait till KS2 before it is understood in any real way. Experience with their shadows in the playground will help children to notice the regular (apparent) movement of the Sun across the sky.
Young children begin to be aware of the seasons, especially the idea of cold winters and warm summers. At KS1 we do well to establish the existence of the seasons of the year. The short winter days and long summer days are often not noticed by younger children so before we offer an explanation for day length it must first be experienced and appreciated.
Most children think the Moon only comes out at night. The grain of truth in this is that it is not easily noticed when it is in the day time sky, so it could be argued that it is not shining, even though it is exactly the same absolute brightness whether it is in the daytime sky or the night sky (see discussion of this in section 4 below.)
Children give several explanations for the changing shape of the Moon. At KS1 children usually draw the Moon as a crescent, and they see it drawn this way in story books. Until they have experienced and appreciated the regular phases of the Moon they cannot be expected to provide explanations.
Young children tend to have a flat view of the universe - a flat, plate-shaped, Earth with the sky above. Stars are drawn as pointed yellow shapes in the night sky. They have great difficulty in moving away from this "up is up" and "down is down" view, and even at the end of KS2 they may still allow the stones in the picture (See Download 2.0a p2) to 'fall' off the bottom of the page, and still imagine the 'round' Earth as a circle of land with a rounded sky above. (See Nussbaum 1985 p 179.)
(AN EXPERIMENT: Download k4.4_3.0b_Early_Years_Astronomy_from_Bulgaria has been provided by Lazarina Bogoeva, a colleague from Bulgaria. In this she describes a project she has done in teaching astronome to very young children. The document is presented exactly as received (no editing is possible) and readers may find the levels of concepts included and modelling expected to be much higher than recommended in this section generally. However, critically and creatively applied some of the ideas presented may be of value even for working directly with trainee teachers or on CPD programmes. This section is experimental - 'to see if it is useful' - so please feel free to provide feed-back directly to the editors and/or to contact the author directly. (Her email address is on the download). AG.
Key Stage 2
Day and night - time
Children still have a range of ideas about the cause of day and night but they should be ready for an explanation depending on the rotation of the Earth. They begin to relate the movement of their shadows in the playground to the rotation of the Earth.
Children at KS2 often explain our cold winters and warm summers by saying we are close to the Sun in summer and far away in winter. The idea that Australia has summer when we have winter begins to be appreciated, so they cannot use the closeness of the Sun as an explanation any more. If children are aware of our short winter days and long summer days the explanation of seasons based on the tilt of the Earth can begin to be appreciated, and it becomes easy to understand why the south has summer when we have winter.
Children at KS2 should have experienced the regular phases of the Moon. They often explain this by saying the Earth's shadow causes the change in shape (this is an explanation of an eclipse, not phases of the Moon). They appreciate that the Moon shines with light reflected from the Sun, and they should be expected to provide an explanation based on the four week passage of the Moon round the Earth, a period of time we call ‘one moonth’.
Even at the end of KS2 some children may still not appreciate that down means towards the centre of a spherical Earth, but most will begin to be able to imagine the Sun at the centre of a solar system of planets. Fewer will realise that the Sun is a star, and that the specks of light we call stars are other suns far far away from our solar system. They will begin to hear the stories of how humans began to unravel the mysteries of the universe. This story is often told only from a Western viewpoint, starting with Copernicus, but many earlier civilisations had already begun to understand that the Earth is a cosmic body and part of the solar system.
Key Stage 3 and 4
Since children at KS2 are usually too inexperienced to understand the phases of the moon, it is a pity that the curriculum for England and Wales does not include a re-visit to ideas about the moon at KS3. The focus at KS4 is to bring in the story of the evolution of the universe, including ideas of stars as element factories, and the universal force of gravity.
Until student teachers (and their pupils) have noticed what is in ‘the heavens’ it is pointless trying to generate explanations. Have they experienced and internalised a clear pattern: to day length and the seasons; to the concept of time-zones; to the phases of the moon and when the moon is visible in the day and night sky; to the patterns made by the stars at night. If a telescope is available they can see craters on the moon, the moons of Jupiter, the individual stars in the Milky Way and some ‘stars’ that are actually galaxies beyond our own milky way.
All sorts of ways can be used to help students come to grips with the motions of the Earth, moon and planets in our solar system. Sometimes an OHP is used for sunlight, sometimes your head is the earth and a tennis ball on a stick is the moon.
There are plenty of good web sites with simulations of the movement of the Earth, moon and planets round the sun.
See below for details of an on-line telescope from which pupils can actually order their own images.
The upgraded Hubble Telescope shows off its talents at http://hubblesite.org/
The Bradford robotic telescope is a completely free web based learning resource. The site’s WebPages are full of useful animations and interactive questions, which support the key concepts of the “Earth and Beyond” section of the national curriculum for key stages 2 - 4. Topics like the phases of the Moon, the role of gravity in space or the annual motion of the constellations through the sky can be backed up by pupils taking their own images of the dark side of the Moon, the orbits of the Jupiter’s moons or by trying to image all of the zodiacal constellations. Almost any item you can think of in the night sky can be observed and the ordering of images is simple with little or no astronomical experience required.
Activities are supported by pupil handouts and teachers notes with minute by minute lesson plans and learning objectives, making this the ideal resources for first time teachers or those working outside their area of expertise.
For more information visit www.telescope.org or email http://www.telescope.org/contact-us.php
Channel 4 (1993) Eureka: If you can get hold of this classic series, it is good for use with primary student teachers and their pupils. It interweaves stories from the cultural history of different civilisations with some very clear models and graphics.
Channel 4 (1993) Eureka: 5 television programmes about space, Earth, seasons and rocks (Nos 1, 2 and 5 cover Earth and beyond)
Power of Ten: Morrison P et al (1994) Powers of Ten New York: Scientific American Library is the original source for a number of websites that take you by powers of 10 from our everyday visual world up to the scale of galaxies and the universe and down through atoms to the fundamental particles of the atomic nucleus.
This is the source for download 3.0a
- West, R. (ed.) (1984) Towards the Specification of Minimum Entitlement: Brenda and Friends London: Schools Council Publication
This in-house publication was used extensively in preparing this unit
- Littledyke, M. et al (2005) Teaching Primary Science Cheltenham: University of Gloucestershire.
A number of standard texts to support students' subject knowledge
- Kennedy J (ed) (1997) "Chapter 12 - The Earth and Beyond" in Primary Science - Knowledge and Understanding London: Routledge
This is the standard text where children’s ideas of the earth as a cosmic body were first brought together:
- Nussbaum J (1985) "Chapter 9 - The Earth as a Cosmic Body" in Driver R et al (eds) (1985) Children's Ideas in Science Milton Keynes: Open University Press
And these are the Primary equivalent - based on the SPACE project, which generated Nuffield Primary Science in the 90’s:
- Nuffield-Chelsea Curriculum Trust (1995) Nuffield Primary Science: The Earth in Space Teachers' Guide, Ages 5-7 London: Collins Educational
- Nuffield-Chelsea Curriculum Trust (1995) Nuffield Primary Science: The Earth in Space Teachers' Guide, Ages 7-12 London: Collins Educational
The National Space Centre in Leicester is a wonderful resource.
Section Developed by:
Keith Ross, University of Gloucestershire January 2006
Published: 10 Jan 2006, Last Updated: 23 Sep 2008