IMPORTANT CONCEPTS RELATED TO LONGITUDE AND TIME ZONES

We are aware that each house has its location and address, for example, the city, the house number, the street’s name etc. In the same way, every single point on the earth’s surface has its respective coordinates defined by the terms ‘latitude and longitude’. The time zones are areas that follow uniformity in their standard time in context with all the purposes, be they commercial, legal or social purposes Every time zone is described as their offsets concerning UTC or Coordinated Universal Time. It ranges from UTC−12:00 to UTC+14:00 hours.

LONGITUDE MEANING 

By definition, the longitude is an angle made directing toward the east or west concerning the Greenwich Meridian. The Greenwich Meridian is considered the Prime Meridian.

Furthermore, the longitude can range from a maximum i.e. 180° east taken from the Prime Meridian and 180° west taken from the Prime Meridian.

The longitude is a coordinate specifying the east-west site of the position of a point on the surface of either the Earth or the surface of any other celestial body. It gives an angular measurement 

The symbolic representation of longitude is expressed usually in degrees. It is denoted by the Greek letter called lambda (λ). The Meridians are the lines running from one pole to another pole. They link all the points having the same measure of the longitude with each other 

Near the Royal Observatory in Greenwich, England, According to the convention, the prime meridian is described as having a zero degree longitude. The east of the prime meridian is marked as the positive longitude, and the west of the prime meridian is marked as the negative longitude.

FACTS IN CONNECTION WITH LONGITUDES

• • In a geographical coordinate system, the prime meridian is described as a line of longitude at which the coordinate of longitude is zero degrees (0°). The great circle comprises both the prime meridian and anti-Meridian.
  • From the prime meridian at 180° west and 0°-180° east, we can measure the coordinates of longitudes for the moon and the earth respectively. 
  • The other prevailing bodies in the solar system, the coordinates of longitude, are measured from their respective prime meridian (0°) to 360 degrees.

• For the direct or the prograde rotations of the bodies (referring to the rotation of the body same as that of the orbit it revolves around), west longitudes are used.

GREENWICH MERIDIAN

• The lines of longitude like that of the known Greenwich Meridian travel from the direction of north to south. They then converge at the site of the poles.

• The range between -180° and +180° is written for the longitude lines.
• The special line (north-south line) is a unique longitudinal line. All of the coordinates of the x-axis begin at 0 degrees. This line is referred to as the Prime Meridian where we measure the east and west direction.

HOW TO PRONOUNCE LONGITUDE

The longitude pronunciation in different languages is as follows:

• As per British pronunciation, the term longitude sounds like ‘long·guh·chood’.
• As per Indian English pronunciation, the term longitude sounds like ‘lawng·guh·chood’.
• As per American pronunciation, the term longitude sounds like ‘laan·juh·tood’.

TIME ZONES

Time zones are those areas that follow uniformity in their standard time in context with all the purposes, be they commercial, legal or social purposes. Rather than following the longitudinal lines, the time zones observe boundaries present between the countries and their respective subdivisions. The reason for this fact is that it is much more convenient to keep the same time in areas with frequent communication calls.

Every time zone is described as their offsets concerning UTC or Coordinated Universal Time. It ranges from UTC−12:00 to UTC+12:00 hours. Mostly, these offsets are written in the form of whole numbers including hours, except a few zones are offset by an additional 30 or 45 minutes, such as in India, Nepal and South Australia.

For a particular segment of the year, daylight saving time is used in areas at high altitude levels. This is done by addition of one hour to the local set time typically in summers and spring.

HISTORY BEHIND THE CONCEPT OF TIME ZONES

• In the past, the apparent location of the sun in the skies, thereby the solar time used to vary in terms of location because the earth is spherical.

• For every taken degree of longitude, the variation correlates with four minutes duration time. For instance, When it is solar noon in London, it is about 10 minutes before the occurrence of solar noon in Bristol, there is solar noon happening in London ranging about 10 minutes.
• The foundation of The Royal Observatory, Greenwich, in 1675 marked the establishment of the GMT or the Greenwich Mean Time. This helped the mariners to measure longitude, the current mean solar time of that site, to measure the longitude at sea level, this gave a standard reference time even when there was non-uniformity of time zones in England.

CONCLUSION 

Summarising the facts, the longitude and also the latitude are called geographical coordinates. They help in determining the location and position of numerous features and coordinates of the earth and they constitute the systematic network of lines. With the assistance of these the different aspects of a point, for instance, the location, distance, direction and coordinates can be easily determined. We can draw infinite meridians and parallels on a globe, but usually, we draw only a selected number on a map. Longitudes are defined in degrees.