Pacific date line
pacific datelineInternational Date Line
Near the 180 is a dotted line known as the Internacional Date Line, something that fascinates regular travellers from all over the world. Let us assume that on our last trip to Japan on Sunday we departed the United States and crossed the Pacific Ocean. Once we get to that date line, it's gonna be Monday.
Arrival at 14.00 hrs on Sunday changes immediately to 14.00 hrs Monday. When you return home, you will reach this line at 11:00 Friday, then 11:00 Thursday, when you head east towards home. What is it about and why do we have to win or loose a whole 24 hour period in one place at once?
This is because every single earth tag must have two borders. We all know one of them - the Midnight Line. It is not fixated on the earth, but constantly moving west as the earth turns east. The position of this midnight line on the earth is directly opposite the star - opposite the degree of meridian on the earth, which is just afternoons.
When you could step on a super-fast missile that travels hundreds of millions of miles per second while you are on your way at midday and drive directly northwards to the Pole without halting there, you would reach the other side of the earth that is witnessing the middle of the night at that moment. It'?s only one limit of every single week.
And the other one is our International Date Line. For example, it was again decided at international level to set this dateline at the ninety-eighth vertex, not because it is particularly important that it is directly opposite Greenwich, but because it is located in the centre of the Pacific Ocean, where there are the least many.
The line, however, jogged to a certain degree eastward and westward of the 180 maridian to prevent a division of the daily between individual policy units such as the Aleuts, which belong to Alaska. In order to give you a clear understanding of why the International Date Line is necessary, we assume that your place of residence is going through the middle of the night, with Wednesday eastward - the new date - while the old date is Tuesday westward of the middle of the night meridian.
Now, step into your fictive supersonic missile and walk back up and past the North Pole on the other side of the Earth, where it's noontime. Not on what date - Tuesday or Wednesday? We need a dateline that is defined on Earth in additon to the dateline of the midnight line; the permanent dateline is the International Dateline.
If it is middle of the night along the date line, the whole earth will experience the same date - that is the only case that this will happen. Now, as the rotating earth leads the middle-night line west towards Asia, it "rolls" the new date, let's say Wednesday, off the date line.
If the midnight line arrives at Greenwich, half of the earth west of Greenwich is still on Tuesday until the date line, the other half on Wednesday. While the Earth continues to spin, Tuesday on Earth shrinks as Wednesday continues to expand until the midnight line returns to the date line.
It is now Wednesday all over the world, but as the Midnight Line continues its westward journey, Thursday is still birth and Wednesday is contracting. One very interesting conclusion of all this - which could even become a true, provocative board games - is that a certain date, or date, stays 48 hrs on Earth - not 24 hrs!
It is a mystery to many, but not a few individuals - some of them seasoned travellers - to imagine why there are different timezones as we move eastwards and westwards, causing this notorious "jetlag" that is so often seen. When the Greenwich Mercury and the Great Border were established, the globe was also subdivided into 24 timezones, each representing 15 longitudes.
It was the notion that each 15 would run down the middle of a region that would be experiencing the same period; this is the ancestry of the Eastern Central, Mountain and Pacific timezones that we use in the United States. Initially, the timezone borders were almost exactly 7 1/2 eastern and western of the zone's maridian, but since then there have been large "Gerrymanders" in these areas - by far the worse outside the United States - because these timezones, such as legal precincts, have been established by politic.
There are many timezone charts of the globe with all its current windings. As a general principle, however, for every 15 degrees of meridian you drive eastward, it is one hours later; the opposite is the case when you drive westward.