Student activity
People shadows
Background information
Our own shadows are created when our body blocks sunlight. Since the Sun appears to
move across the sky during the day, our shadows change shape. The time of day when
shadows are shortest is when the Sun is due north. Shadows of people almost
disappear when the Sun is directly overhead – the only shadow is directly beneath them.
In Melbourne the Sun is never directly overhead. The only areas of Australia that have
the Sun directly overhead during the summer are north of the Tropic of Capricorn.
Always ensure that students are warned never to look directly at the Sun.
What you need

Coloured chalk
What to do
1. Go outside to an open asphalt/concrete area early in the morning. Work in pairs.
Take turns to stand in a scarecrow position while your partner traces around your
shadow using coloured chalk. Now swap over.
2. Place a sign requesting that no-one rubs off the chalk during the day.
3. Return to the same position before lunch, at lunchtime, and again in the afternoon.
Each time stand in the same position and use a different coloured piece of chalk to
trace the shadows. Label the different coloured shadows to indicate which shadows
were cast in the morning, at lunchtime and in the afternoon.
4. Discuss what happened to the
shadows and list any suggestions you
have to explain their different size and
direction.
5. You could repeat this exercise at other
times of the year e.g. March, June,
September and December. Discuss
your results.
Tracing shadows
http://www.ldcsb.on.ca/comm/news/spotlightjune222007.htm
http://museumvictoria.com.au/scienceworks/education/
36
Student activity
Using shadows to tell the time
Background information
Shadows were once used to give some indication of time using only a stick and its
shadow. The Sun is at its highest point in the sky around midday, when it casts its
shortest shadow. When the Sun is close to the horizon, it casts a long shadow.
The maximum altitude of the Sun varies throughout the year. In Melbourne, the Sun
reaches a maximum altitude of 75 degrees in summer (21 December). The Sun rises in
the southeast and sets in the south-west, making the days long and the nights short.
During winter, the Sun is much lower and the maximum altitude it reaches in Melbourne
on 21 June is only 28 degrees. The Sun rises in the north-east and sets in the northwest, and the days are short while the nights are long.
Always ensure that students are warned never to look directly at the Sun.
What you need






Access to an open asphalt or concrete area
Watch
New pencils
Large sheets of cartridge paper
Plasticine
Coloured chalk
What to do
1. Stand a pencil vertically in the centre of a
large piece of cartridge paper, using a piece
of plasticine.
2. Take the paper outside to an open
asphalt/concrete area. Trace around the edge of the paper and the base of the
plasticine in case they move out of place. On each side of the paper write or draw an
orientation landmark such as shelter shed, playground etc. This will enable you to
return the shadow stick to the same position for each reading.
3. Every hour, draw over the shadow of the pencil and mark the time. Continue to mark
the shadow every hour until 2.00pm. You should aim to have at least five shadows
marked (10am, 11am, 12 noon, 1pm, 2pm).
4. At each reading, note the position of the Sun using features in the landscape. For
example, at ten o’clock the Sun was just above the corner of the shelter shed.
5. After a few readings try to predict the length and direction of the next shadow.
6. Repeat the same activity the next day. Try to predict the outcome. Discuss how this
could be used as a clock. How reliable is it? Try to explain why the shadows change.
7. The Sun appears to move from east to west but in fact it is the Earth that is turning
from west to east.
http://museumvictoria.com.au/scienceworks/education/
37