Realizing an exact definition of continent is more difficult than it can be supposed. A continent is a large-sized unit of land that can be distinguished from smaller ones (such as countries) for reasons of geography or culture.
There is no specific number of continents: it all depends on the perspective followed when distinguishing between one continent and another. Through one of the most common ways of listing and characterizing them, we obtain the following list:
* Africa, which is distinguished from Europe by the separation of the Strait of Gibraltar and Asia by the Suez Canal ;
* Antarctica, which is located in the area around the South Pole ;
* America, separated from Asia through the Bering Strait. It is usually divided into three subcontinents: South America, Central America, and North America ;
* Asia, a region bounded by the Indian Ocean and the Bering Strait ;
* Europe, which extends to the Iberian Peninsula ;
* Oceania, located in the southeast of the Asian continent.
According to this notion, the continents are six: Africa, Antarctica, America, Asia, Europe and Oceania. Some even consider that Europe and Asia form a single continent (known as Eurasia), while others add Africa to this entity (Euraphrasia).
Another trend includes the Australian continent, also known as Sahul, which would be made up of mainland Australia, New Guinea, Tasmania and the eastern island territories of the Malay Archipelago from the Wallace line.
If we refer to the most usual division, the largest continent is Asia (with an area of 43,810,000 square kilometers), followed by America (42,330,000), Africa (30,370,000), Antarctica (13,720,000), Europe (10,180,000) and Oceania (9,010,000).
When taking into account the population level, the first place is occupied by Asia. Behind are Africa, America, Europe, Oceania and Antarctica, in that order.
The formation of the current continents
Thanks to the studies carried out over the years by scientists from different fields, such as historians, physicists and geologists among many others, we know that everything on Earth, even the huge continental masses, is in constant motion.
There are many opinions regarding the formation of the Earth and its division into the continents that we know today, the most widely accepted theory being the Pangea theory, which was proposed by the German-born meteorologist and geophysicist named Alfred Wegener.
Wegener affirmed that the Pangea, formed around 300 million years ago, had been the product of the unification of large fragments of land (continents) that at that time were separated and had joined forming a single continent completely surrounded by water, an ocean called Panthalassa.
After 20 million years of evolution and due to the centrifugal action caused by the rotation of the Earth, this continent began to fragment and move. This rupture originated simultaneously in both the North and the South, leaving two widely differentiable blocks: to the north were located what we now know as North America and Asia, united, a region that received the name of Laurasia; on the other hand, to the south, our Antarctica, Australia and India, made up the so-called Gondwana. Their division continued progressively, until the map of the Earth acquired its present appearance and distribution.
The displacement of land masses has never stopped; Since the separation of the continents, the earth has continued to move and, according to some scientists, it is very possible that in the future all the continents will be unified again. This idea of the return of Pangea is fascinating and raises many questions. Will it be possible to live so close to each other?