Space is the limitless, boundless, three-dimensional extent where objects and events occur and have relative position and direction. Generally, physical space is conceived in 3 linear dimensions, although modern physicists typically consider it (along with time) to be part of the boundless four-dimensional continuum that is known as spacetime.
In the world of mathematics, ‘spaces’ are usually examined with different numbers of dimensions and with different underlying structures. Space, the concept, is generally considered to be of critical importance to an understanding of the physical universe – although philosophers disagree about whether space is itself an entity, a relationship between entities, or part of a conceptual framework.
In the view of the great English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian Isaac Newton (1643-1727), space was absolute – in the sense that it existed permanently and independently of whether there were any matter in the space. Other philosophers such as Gottfried Leibniz, thought instead that space was a collection of relations between objects, given by their distance and direction from each another.
In the 18th century, the German philosopher Immanuel Kant described space and time as elements of a systematic framework that humans use to structure their experience. In 1905, the brilliant theoretical physicist and philosopher, Albert Einstein, published a paper on a special theory of relativity, where he proposed that space and time be combined into a single construct known as spacetime.
Ultimately, space is best described as the continuous extension in all directions in which all matter exists, and this is our final answer to the question, what is space?
What is Outer Space?
Outer space is generally described as anything beyond the atmosphere of Earth. There is no air to scatter the light, thus what we see when we look up into the night sky is a black emptiness spangled with stars, planets and other extraterrestrial matter. It is important to understand however, that ‘space’ does actually include everything within the Earth’s atmosphere as well as all of the land and water on its surface.