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12.2 Does the Earth move?

If you look up to the The Earth has been in existence
sky at different times for around 4.6 billion years, and
of the day you will see the way it moves around the

that the Sun appears Sun has influenced how life on
textbooks nis edu kz
Earth has evolved. Initially, there
to move from east to
were two possible explanations
west across the sky.
about the movement of planets:
The stars in the night
that the Earth is stationary, Demonstration of Foucault’s
sky also appear to while stars and planets revolve pendulum, 1851 (engraving, 1890)
move in a similar way. around it; or that the Earth rotates on its own axis.
Why do you think this We have known for some time that the Earth rotates on its own axis, but
happens? the best experimental evidence to prove it came in 1851 using a large

pendulum called the Foucault pendulum. The time it takes for the Earth
to rotate around its own axis is called a day.
DID YOU KNOW?
ACT To understand the world we live in, we use models to help us explain
The transition from one
it. Think about how you can demonstrate and explain the change from
season to another comes
day to night on the Earth to your classmates using everyday objects.
at specific points in time:
Discuss the advantages and disadvantages of your model.
June 21 is the summer
solstice, signalling the The changing landscape: The seasons and
longest day in the northern
hemisphere; December 21 the year
marks the winter solstice, In order to keep track of planting, growing and harvesting crops, as well
with the longest night in the as rituals, early humans watched how the Earth moves and changes over
northern hemisphere; and time. The first clue in this mystery is the observation of the seasons.
March 22 and September
23 mark the timing of the
spring equinox and autumn
equinox – the points at which
the length of the day is equal
to the length of the night.

ACT Look at the images above. Why do you think this happens to the
landscape? Why do humans need to understand this cycle very well?

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