We explain what space is according to its different meanings: physical, external, geographical space, and its relationship with time.
What is space?
It is not easy to explain what space is, since it is a term that can have many and very different meanings, depending on the context that accompanies it. The word space comes from Latin spatium, term with which the philosophers of yesteryear referred to the matter, terrain or weather that separates a point A from a point B.
Its first definitions in the Dictionary of the Spanish Language point to terms such as "extension", "distance", "capacity" or "course", since deep down we understand by space a proportion or relationship.
Thus, space is the portion of the world that a given body occupies, and that cannot be occupied by any other at the same time. Space is also the distance between one thing and another, or even the period of time between one event and a different one.
At the same time, we call the whole space universe outside of our planet. We also give the term other specialized uses, such as geographical space.
All these meanings are true in context and warrant a separate explanation, which we will discuss below.
Physical space
Physical space is the place that an object occupies in the universe, conceived based on the three customary linear dimensions: height, width and depth. In that sense, space is a key concept for the physical understanding of the universe.
It is mathematically calculable and questioned by the physical contemporary. Its relationship with time has been known since ancient times, but it was fully developed in the 20th century by Albert Einstein, as we will see later.
In classical mechanics or Newtonian mechanics, space constitutes one of the elementary magnitudes of the universe, which is not definable through other similar magnitudes (such as time, mass, etc.).
Space and time
The relationship between space and time occupied a central place in the philosophy 17th century. For this reason, great thinkers such as the English physicist Isaac Newton (1642-1727) and the German philosopher and mathematician Gottfried Leibniz (1646-1716), developed very dissimilar theories to understand it.
Mechanics Newtonian understood space and time as absolute values. Thus was founded the classical mechanics that have survived to this day. This conception changed with relativism in the 20th century, whose most famous name is Albert Einstein.
Despite the fact that there had already been attempts to overcome the traditional geometric considerations of space, through non-Euclidean geometry, it was not until 1905 that this new way of understanding the link between space and time appeared.
Albert Einstein's theories held that neither of these two magnitudes is really absolute, but rather depends on the observer's point of view. In this Theory of relativity Especially, Einstein proposed that time and space formed a single construction: the space time, the fabric of which the universe is composed.
Outer space
The concept of outer space arises with the possibility of knowing the universe beyond our planet. Outer space is the vast expanse of emptiness between the end of atmosphere and the beginning of the other planets distant.
It is called "outer" as opposed to the inner space of the planet. This space, however, is not really empty of matter or of Energy, but contains a density extremely low of particles (especially hydrogen) and electromagnetic waves.
The exploration of outer space was limited for many centuries to observation through telescopes. Only in the twentieth century could the first objects be put into orbit.
In addition, in 1969 the first astronauts arrived in the Moon, initiating the physical and technological exploration of outer space, through the launching of space probes and, later, unmanned missions to Mars and other planets.
Geographical space
For its part, the concept of geographic space belongs to the field of geography. It is the same physical space, but ordered by the society human. In other words, it implies a look at human society from a spatial point of view.
The geographical space is divided into scenery: each according to the order of things that you want to perceive. You can talk like this about natural landscape, urban landscape, Rural landscape, etc.