Globe Latitude and longitude

It lies close to poles. In this zone the sun does not rise much above horizon so its rays are always slating and provides less heats. That is why these zones are very cold.

Parallels of latitudes: - All parallel circles from the equator up to the poles are called parallels of latitudes.
Longitudes. It is the area of the equator between the meridian of a place & a standard meridian.

LOCAL TIME: Local time is the real time of a place according to its corresponding longitudes. Every place has its unique local time. Places having the same meridian of longitude have the same local time.
STANDARED TIME: Standard time of a place is the time of that time zone in which that place lies. In countries with large east west extant variations in local time are present; to overcome this problem standard time of specific time zone is taken as standard time of that place.

Standard time is necessary because

1. The different meridian’s having different time is likely to create problems for trains & flights.
2. To maintain uniformity in the throughout the country.
3. The local time over 82o 30’ is considered standard time.

This is because India is located at 82.5 degree lies east of London which is at 0 degree longitude .Sun moves at 15 degree per hour or one time zone per hour speed from east to west . so it takes 5.30 hours by sun to reach London from India . That is why there is a difference of 5.30 hours.

(b)Decrease time in his watch

Since earth moves 360° in 24 hours, then, 15° in an hour and 1° in four minutes. 30° east means 30 × 4 = 120 minutes ahead of Greenwich. This implies where at 30° east time is 2 p.m. then at Greenwich time = 2 pm – 2 hours = 12 p.m.

The mid-day sun is exactly overhead at least once in a year on all latitudes in between the Tropic of Cancer and Tropic of Capricorn. Therefore, this area receives maximum heat.

A globe is a true model of the earth. Globes can be of varying sizes and types. Big ones are those which cannot be carried easily, small pocket globes and balloon globes that can be inflated, are handy and are carried with ease.

The Meridian which passes through Greenwich, where the British Royal Observatory is located is called the Prime Meridian. Its value is 0o longitude.

Since earth moves 360° in 24 hours, then, 15° in an hour and 1° in four minutes. 30° east means 30 × 4 = 120 minutes ahead of Greenwich. This implies when at 30° east time is 2 p.m, and then at Greenwich time will be 2 pm – 2 hours = 12 p.m

In the figure, three places namely a, b and c are marked. Let us assume that time difference between ‘a’ ‘b’ and ‘c’ is 1 hour each. If the time at a place ‘b’ is 6 in the morning than the time at ‘a’ would be 5 in the morning and time at ‘c’ would be 7 in the morning. The time at place ‘a’ is 1 hour less because it is to the west of ‘b’ and time at ‘c’ is 1 hour more because it is to the east of ‘b’. This is due to the fact that earth rotates from west to east. As the sun rises in the east so place ‘c’ has 7am, place ‘b’ has 6am and place ‘a’ has 5am. This shows that time increases as we go towards east and it decreases as we go to west.

The mid–day sun never shines overhead on any latitude beyond the tropics. The angle of the sun‘s rays goes on decreasing towards the poles. As a result, the places between tropics to Arctic and to Antarctic Circle have moderate temperature.

Latitudes and longitudes can locate the exact location of a place but, they are not uniform units of measurement.
i) If you look in the globe, you will see that longitudes are closer together as you move towards north and south of Equator.
ii) Only near the Equator the distance represented by 1° longitude is equal to the distance represented by 1° latitude.

Latitudes and longitudes are expressed in degrees. However, the increments of less than one degree can be expressed as a decimal or minutes and seconds. There are 60 minutes in a degree and 60 seconds in a minute. Longitudes can be written with an E or W for east or west. Latitudes have N or S for north or south.

Latitude and longitude allow you to use two coordinates to define any point on earth. Latitude and longitude have been useful to navigators, geographers, cartographers and surveyors for a long time. Latitude and longitude are useful on a daily basis for a great number of people for global positioning system, GPS and computerised mapping. Using latitude and longitude, it is possible to calculate all sorts of things such as calculate the distances from city to city, calculate the distance from any point on earth to any other point. For example, we can calculate the distance from your house to school.

The International Date Line (IDL) is an imaginary line on the surface of the Earth opposite the Prime Meridian, where the date changes as one travels across east or west. Roughly along 180° longitude, it almost corresponds to the time zone boundary separating -12 and +12 hours Greenwich Mean Time (GMT). Crossing the IDL, travelling east results in a day or 24 hours being added and crossing west results in a day being subtracted. The exact number of hours depends on the time zones.