Before entering fully into the analysis of the meaning of the term meridian, it is advisable to proceed to determine its etymological origin. Thus, it must be made clear that it is a word that emanates from Latin, and more precisely from the word “meridianus”. This is the result of the sum of two Latin words: “meridies”, which can be translated as “noon” and which in turn is composed of “medius”, which is synonymous with “medium”, and “dies”, which is equivalent a day”.
Meridian is a term that, according to Royal Spanish Academy (RAE), refers to pertaining to or relating to the time of noon. By extension, the concept is used as an adjective to name something that is very bright or very clear.
The meridians, on the other hand, are the great circles of the earth’s sphere passing through the poles. It can be said that the meridians are imaginary lines, which are used to fix the schedule.
The base meridian from which longitudes are measured is the Greenwich Meridian. This imaginary circumference that joins the poles for by the old astronomical observatory of the English city of Greenwich and was adopted as a reference in 1884.
From north to south, the Greenwich Meridian traverses United Kingdom, France, Spain, Algeria, Mali, Burkina faso, Togo and Ghana.
It is interesting to note that currently one of the greatest tourist attractions in this English city is the Royal Astronomy Observatory, which dates from the second half of the 17th century. Thus, many are the visitors who are encouraged to know it in depth and who are amazed by the exhibitions that it includes both chronometers and all kinds of navigation tools. Of course, without forgetting that it has interesting horological artifacts and star and planet observation.
The meridian that passes through the point where an observer is located is called local meridian. This meridian can be divided into two semi-circumferences by the axis of rotation of the Land: the upper meridian (P.M) and the lower meridian (A.M).
The solar time is the measure of weather which is based on the apparent movement of the Sun over the horizon. When the sun passes through the meridian, it reaches its highest point in the sky and noon is established.
All this without overlooking the fact that in the field of astronomy there is what is known as a meridian telescope, which is one that is used to observe the stars and that is placed on a horizontal axis.
In addition to all the above, we would have to emphasize that there are other terms that are also used by the one at hand. Thus, for example, there is the so-called meridian plane, which is that plane that has the peculiarity of passing through what would be the axis of revolution of a surface.
Other uses of the notion of meridian refer to the sofa without arms or backrest, the stretcher and the nap that takes place after a meal.