Time

Time

Time can be measured in various ways. You can tell the time roughly by looking at the length of shadows. But the need for accurate time became important, in general, when railways spread around the world in the mid-1800s and train timetables were developed. Now time can be measured even more precisely with atomic clocks, using the vibration of atoms.

Night and day

People on opposite sides of the world have day and night at different times. As the Earth spins round, half the world is in day light and the other half, facing away from the sun, has night. When it is 11 o’clock in the morning in London, UK, the time in Sydney, Australia is 9 o’clock at night.

First calendars 

Calendars help to keep track of days, weeks, months and years. The Mayan people of Central America made calendars on the ground, in the shape of the Sun. Signs for the days were carved around the periphery. Time was tracked by the Sun’s movement.

Giant calculator

Stonehenge, in England, is a huge circle of stones, thousands of years old. Some astronomers (people who study the stars and planets) believe it was built to tell the time of the seasons by the shadows that the stones cast.

Sands of time

An hour glass contains sand in a glass container. The sand runs through a small hole. It was a popular type of clock in the Middle Ages (between the years 470 and 1450), when it was used to measure short period of time.

Refer the given composition to answer the following questions:

1. How can anyone tell the time roughly just by looking at the shadow?

(A) By the width of the shadow     (B) By the colour of the shadow

(C) By the length of the shadow    (D) By the shape of the shadow

2. Why the need for the accurate time became important?

(A) Because of the school time table

(B) Because of the airways time table

(C) Because of the bus timetable

(D) Because of the railways timetable

3. How can we measure time more precisely?

(A) By hour glass                             (B) By atomic clock

(C) By shadow                                  (D) None of these

4. Which part of the earth has day?

(A) The part that faces towards the moon.

(B) The part that faces away from the Sun.

(C) The part that faces towards the Sun.

(D) The part that faces away from the moon.

5. When it is 11 o’clock in the morning in London, the time in Sydney is _______.

(A) 10 o’clock in night                    (B) 11 o’clock in morning

(C) 9 o’clock in morning                 (D) 9 o’clock in night

6. Where was the first calendar made?

(A) On the paper                            (B) On the ground

(C) On the leaf                                 (D) On the board

7. The people who study the stars & the planets are known as _________

(A) Astronauts                                  (B) Pilots   

(C) Astronomers                               (D) Astrologers

8. In which country is the Stonehenge situated?

(A) England         (B) America         (C) India               (D) China

9. What does an hour glass contain in a glass container?

(A) Stones            (B) Water             (C) Atoms            (D) Sand

10. How can we know the precise time by an atomic clock?

(A) By the mixing of atoms  

(B) By changing the shapes of atoms

(C) By the vibration of atoms

(D) By the breaking of atoms

Answer keys
(1) (C); (2) (D); (3) (B); (4) (C); (5) (D); (6) (B); (7) (C); (8) (A); (9) (D); (10) (C)