Science and Technology K–6 · Years 5–6

Shadow stick: tracking the Sun across a school day

Science understanding: Physical sciences

Practical, model not builtLow risk

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The idea

A shadow forms where an object stops light travelling in straight lines from the Sun, so the length and direction of a stick's shadow record the Sun's height and position through the day and the year.

What you need

a straight stick exactly 1.000 m long set vertically in open ground (check with a spirit level)
a large sheet of paper or chalk on concrete around the base
tape measure in centimetres, grid paper, a protractor and a magnetic compass
a clock set to Australian Eastern Standard Time
the school's latitude and longitude (Sydney: 33.87 degrees south, 151.21 degrees east)

How to do it

From 9 am, mark the tip of the shadow every 30 minutes until 3 pm, writing the time beside each mark.
Measure each shadow's length and its direction and record both in a table. A magnetic compass points to magnetic north, which in Sydney is about 12.8 degrees east of true north (World Magnetic Model 2025, September 2026), so correct each compass reading by that amount, or measure directions from the noon shadow, which lies along the true north-south line.
Find the shortest shadow: that is local solar noon. Record the clock time and the direction the shadow points (south of the Tropic of Capricorn it always points south, because the noon Sun is always to the north; in the tropics, such as Darwin, it points north from about late October to mid-February, when the noon Sun is south of overhead).
Find the Sun's elevation at each mark with a scale drawing: on grid paper draw the stick 10 cm tall (1 cm for every 10 cm) and the shadow to the same scale along the base line, join the top of the stick to the tip of the shadow and measure the angle at the shadow's tip with a protractor. The live model gives the same angle for checking.
Graph elevation against clock time.
Repeat near an equinox and a solstice and compare the noon elevations with the model.

What you should see

Shadows are long and point roughly west to south-west in the morning, shorten to a minimum pointing due south (true south, which a compass in Sydney reads as a bearing of about 167 degrees) near 11:55 AEST in Sydney (solar noon sits before 12:00 because Sydney is 1.21 degrees east of the 150 degree standard meridian, 4.8 minutes, before the equation of time is applied), then lengthen toward the east. At an equinox the noon Sun in Sydney stands 56.1 degrees high and a 1.000 m stick casts a 0.671 m shadow; at the June solstice the noon elevation is 32.7 degrees (shadow 1.56 m) and at the December solstice 79.6 degrees (shadow 0.18 m). Never look at the Sun; the stick does the looking.

What changes

What you change: time of day (and date between repeats)
What you measure: shadow length and direction
What you keep the same: stick height and verticality
same site
level ground

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

The Sun is straight overhead at noon in Sydney (it never is; 79.6 degrees is the highest).
The Sun moves across the sky (the Earth turns).
Shadows are always shortest at exactly 12:00 by the clock.

Safety card

Low riskLearners carry it out

Hazards

looking at the Sun
sun exposure

Controls

never look at the Sun, with or without any glass
hats, sunscreen, shade breaks

Note

Risk assessment before the lesson using Primary RiskAssess or the school's own template.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Science and Technology K-6 Syllabus (2017), current, taught until 2026; a Stage 2 outcome, because NSW teaches this activity in Stage 2 ('construct a way of observing and recording changes in the Sun's position in one day'), and neither the Stage 3 content under ST3-10ES-S nor the 2024 Stage 3 content covers the Sun's daily path; code read from the syllabus document on 22 September 2026ST2-10ES-S
Science and Technology K-6 Syllabus (2017), current, taught until 2026; code read from the syllabus document on 22 September 2026ST3-1WS-S
Science and Technology K-6 Syllabus (2024), implemented from 2027; NESA's timeline is 2026 plan and prepare and 2027 start teaching, and schools may choose to implement it during 2026; code read from the outcomes page on 22 September 2026ST3-DAT-01
Australian Curriculum v9AC9S5U03AC9S6U02AC9S5I03AC9S5I04

Sources

The pages the author read to write this activity.

All Concept Studio activities