LATITUDE & LONGITUDE

These are the imaginary lines made to plot the earth on two dimensional coordinate system. In two dimensional coordinate system the horizontal axis is called as x-axis and vertical axis in known as y-axis. So the earth's x-axis or horizontal axis is called equator. The vertical axis or y-axis is called as Prime Meridian is at Greenwich, England.

But unlike the coordinate system whose axes tends to infinite, the earths axes are finite and are measured in degrees, minutes and seconds. The longitude is measured as 180 deg.on right side of y-axis called 180 deg East and 180 deg on left side is called as 180 deg. West.


LATITUDES LONGITUDES



Similarly the latitudes is measured as 90 deg North above the x-axis or equator and 90 deg South below the equator.


Why we demarcate the Earth?

It is similar to locate a point on a coordinate system. With the measurement of latitude and longitude we can locate any place on the Earth. Suppose we want to know where 'Delhi' is located. If the answer is "Delhi has a longitude of 77 deg 13'E and latitude of 28 deg 39'N".
It means that on East side that is right side on Prime Meridian by 77 deg 13' and North side of equator by 28 deg 39'.




Where these angles are formed as we measure in degrees?


Imagine the Earth was a transparent sphere (actually the shape is slightly oval; because of the Earth's rotation, its equator bulges out a little). Through the transparent Earth (drawing) we can see its equatorial plane, and its middle the point is O, the center of the Earth.

To specify the latitude of some point P on the surface, draw the radius OP to that point. Then the elevation angle of that point above the equator is its latitude λ--northern latitude if north of the equator, southern (or negative) latitude if south of it.

Every meridian must cross the equator. Since the equator is a circle, we can divide it--like any circle--into 360 degrees, and the longitude φ of a point is then the marked value of that division where its meridian meets the equator.

Longitude lines or "meridians"

What that value is depends of course on where we begin to count--on where zero longitude is. For historical reasons, the meridian passing the old Royal Astronomical Observatory in Greenwich, England, is the one chosen as zero longitude. Located at the eastern edge of London, the British capital, the observatory is now a public museum and a brass band stretching across its yard marks the "prime meridian."

LEAP YEAR

A leap year (or intercalary or bissextile year) is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year.

In the Gregorian calendar (a common solar calendar), February in a leap year has 29 days instead of the usual 28, so the year lasts 366 days instead of the usual 365. Similarly,

In the Gregorian calendar, the current standard calendar in most of the world, most years that are evenly divisible by 4 are leap years. In each leap year, the month of February has 29 days instead of 28. Adding an extra day to the calendar every four years compensates for the fact that a period of 365 days is shorter than a solar year by almost 6 hours.

However, some exceptions to this rule are required since the duration of a solar year is slightly less than 365.25 days. Years that are evenly divisible by 100 are not leap years, unless they are also evenly divisible by 400, in which case they are leap years. For example, 1600 and 2000 were leap years, but 1700, 1800 and 1900 were not. Similarly, 2100, 2200, 2300, 2500, 2600, 2700, 2900 and 3000 will not be leap years, but 2400 and 2800 will be. By this rule, the average number of days per year will be 365 + 1/4 − 1/100 + 1/400 = 365.2425, which is 365 days, 5 hours, 49 minutes, and 12 seconds.

What does 'A' rated movie mean?

The Central Board of Film Certification (popularly known as the Censor Board) is a government of India regulatory body and censorship board of India by Ministry of Information and Broadcasting. It reviews, rates and censors motion pictures, shows, television ads and promotional material. It regulates the public exhibition of films in India under the provisions of The Cinematograph Act 1952. Films can be publicly exhibited in India only after certification by the Board.

The CBFC currently issues the following certificates.

Symbol	Name	Definition/Notes
U	Universal	All ages admitted, there is nothing unsuitable for children. Films under this category should not upset children over 4.
U/A	Parental Guidance	All ages admitted, but certain scenes may be unsuitable for children under 12.
A	Adults Only	Only adults are admitted. Nobody younger than 18 may rent or buy an A-rated VHS, DVD, Blu-ray Disc, UMD or game, or watch a film in the cinema with this rating. Films under this category do not have limitation on the bad language that is used. Hard drugs are generally allowed, and strong violence/sex references along with non-detailed sexual activity is also allowed.
S	Restricted to any special class of persons	This rating signifies that the film is meant for a specialised audience, such as doctors.