More to Explore People in the past used shadows of objects to tell the time. The device for observing shadows is called a ‘sundial’. You can visit the Astropark in Sai Kung or the Yuen Chau Kok Park in Sha Tin to learn about different kinds of sundials.
3. Visit the Hong Kong Observatory website to find out the time of sunrise in Hong Kong in the past two days. How much time had passed between one sunrise and the next?
Date and time of sunrise
The first day
Time passed: about hours
On
, at
a.m.
The second day
On
, at
a.m.
Quick Check
我發現 The Earth needs
1
hours to complete a full rotation,
which is
day.
Do this activity to make a sundial and find out how its shadow changes in the sunlight at different times of the day. Activity Booklet 4 2 How do shadows change in the sunlight at different times of the day?
Astropark
2
Yuen Chau Kok Park
Why can we use sundials to tell the time?
我發現 Quick Check
At different times of the day, shadows formed in the sunlight are the same / different in terms of length and direction.
The Sun does not move around the Earth. We see sunrise and sunset because the Earth rotates.
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