Year 6 · fifth unit

The Changing Seasons

Summer is hot not because we are nearer the Sun. It is because the Sun climbs high. And the Sun climbs high because the Earth is tilted.

A child who has stood a stick in the playground and is putting stones at the tip of its shadow

I stood a stick in the playground

A board to run

Run a day. Watch how the length of the shadow and the air temperature change. Change the season too.

A playground where stones placed at the tip of a stick's shadow trace a curve

Midday in summer and midday in winter: how high is the Sun?

A board to adjust

Change the month. Watch the area the same bundle of sunlight falls on.

The height of the Sun seen from the same spot at midday in summer and in winter

Which month

If the Earth stood upright, would the seasons disappear?

A board to adjust

Change the tilt of the axis. The line below is the midday height of the Sun in Seoul through the year.

Four globes going round the Sun on a tilted axis

Tilt of the axis (°)

What comes next in middle school · stars and the universe

From the Sun's height alone

It is the midday Sun from above. Its height can be worked out from just where you live (the latitude) and the month. And the strength of the sunlight a patch of ground receives is fixed by that one angle.

The height of the Sun measured with a protractor, on dark paper

The Sun from above

A board to adjust

This time there are numbers. Change where you live and the month.

Which month Latitude (Seoul 37.5°)

—midday height of the Sun

—sunlight received

Back up to the basics