Measuring time on the earth

People can determine the approximate time of day by determining where the Sun is in the sky. If the Sun is near an imaginary line drawn from due north to due south, it is about 12:00 noon. Humans have used movements of the Earth, the Moon, and the Sun to measure time for thousands of years. Around 3000 B.C., the Babylonians devised a method of timekeeping using their counting methods, which were based on 60. They noticed that the Sun appeared to take a circular path through the sky. Because their counting methods were based on 60, they divided a circle into 360 parts called degrees. The symbol for degree є was taken from their symbol for the Sun.

The Earth spins and makes one complete turn in about 24 hours. This spinning causes the Sun to appear to move across the sky from east to west. It takes 24 hours from when the Sun is highest in the sky (noon) until it is highest in the sky again (noon the next day). If the Earth spins approximately 360° in 24 hours, then it spins through 15° in one hour. This led to the setting up of time zones on the Earth that have the same time in minutes but vary in hours. A time zone is an area 15° wide in which the time is the same. Ideally, time zones should be equal in size and follow lines drawn from the North Pole to the South Pole. However, for convenience, time zones are modified to fit around city, state, and country borders, and other key sites.

You can see that a problem would quickly arise if you just kept dropping back an hour earlier for each 15°. Eventually, you would come around the Earth and it would be 24 hours earlier. It cannot be two different days at the same spot, so a day is added to the time at the International Date Line. If it is Monday to the east of the date line, then it is the same hour on Tuesday to the west of the date line. This line is drawn down through the Pacific Ocean (around islands, such as New Zealand) directly opposite the Prime Meridian, the starting point for this worldwide system of measuring time. The Prime Meridian is an imaginary line drawn on the Earth that passes through Greenwich, England. Time based on this method is called Coordinated Universal Time (UTC). In some areas, this time is modified in summer so that there are more hours of daylight in the evening. This is referred to as Daylight Saving Time (DST). Some areas apply local modifications to this system as well. If you look at the globe, you will see that the globe is divided into 24 time zones. Lines of longitude roughly determine the locations of time zone boundaries. Notice that each successive time zone to the west is one hour earlier.

Ex.13. Find in the text equivalents for the following Russian words and word combinations:

определить приблизительное (неточное) время; точно с севера на юг; измерять время; жители Вавилона; изобрести метод слежения за временем; способы счета; заметить что-либо; градус; символ для; с Запада на Восток; совершать круговые вращения; пройти по небу приблизительно 15 °; привести к чему-либо (стать причиной для); установить (создать) временные зоны; Северный Полюс; Южный Полюс; прочертить (провести) линии; видоизменять, модифицировать; границы страны; ключевая (основная) точка местоположения; возникнуть (о проблеме); в одном и том же месте; нулевой (главный) меридиан; всемирная система измерения времени; воображаемая линия; проходить через (о линии, меридиане); земной шар (глобус); делить на временные зоны.

Ex.14. Answer the following questions:

1. What is the way of determining the approximate time of the day?

2. Humans have used movements of the Earth, the Moon, and the Sun to measure time for millions f years, haven’t they?

3. When did the Babylonians devise a method of timekeeping using their counting methods?

4. Were the Babylonians’ counting methods based on 60 or 120?

5. What did the Babylonians notice concerning the Sun?

6. How many degrees did the Babylonians divide a circle into?

7. How long does it take from when the Sun is the highest in the sky (noon) until it is the highest in the sky again (noon the next day)?

8. What did the symbol є mean for the Babylonians?

9. What led to the setting up of time zones on the Earth?

10. A day is added to the time at the International Date Line, isn’t it?

11. How many time zones is the globe divided into?

12. How wide is an area of a time zone?

13. What is the so called “Coordinated Universal Time”?

Ex.15. Retell the text “Measuring time on the Earth”.

Ex.16. Listen to the dialog “At the post-office”.

Ex.17. Answer the following questions:

1. How many stamps did the customer want to buy?

2. How much did the customer pay for the stamps?

3. How much postage did the letter to the New York State Department of Taxation need?

4. How much did the clerk charge for the money order to the English Language Textbooks Organization?

5. What is the address of the English Language Textbooks Organization?

6. What was the total postage for all the post errands?

Ex.18. Decide whether these statements are true or false.

1. The customer sent the letter to the New York State Department of Taxation by recorded delivery.

2. The customer bought ten 25-cent stamps.

3. To make sure that the letter to the New York State Department of Taxation gets there on time, the customer filled out the form and signed it.

4. The customer also filled out the money order form.

5. The customer sent the money order by ordinary mail.

6. The money order weighted 20 ounces.