p When we look closely at the objects around us we find that each one is not ’only in motion, but also possesses extension, or size. Objects may be big or small, but they all have length, width and height, occupy a definite place, and have a volume. Objects in nature possess not only extension, but are also located in a certain way in relation to each other. Some of them are located farther away from us or nearer to us than others, higher or lower, to the right or to the left.

p The philosophical concept of space reflects the universal property of material bodies to possess extension, to occupy a definite place and to be located in a particular way among other objects of the world.

p Objects not only exist in space, but also follow each other in a definite sequence. The place of some objects is taken by others, which in turn are replaced by still others and so on. Every object possesses some duration of existence, has a beginning and an end, and goes through certain stages or states in its development. Some objects are only beginning to arise, others have become established and are developing, while still others are in the process of destruction.

p The philosophical concept of time reflects the universal property of material processes to follow one after another in a definite sequence, to possess duration and develop by stages.

p Space and time are universal forms of the existence of matter. “There is nothing in the world but matter in motion, and matter in motion cannot move otherwise than in space and time,”  [52•*  Lenin wrote.

p The most important attribute of space and time is their objectivity, i.e., independence of man’s consciousness. This is natural for they are the basic forms of objectively existing matter.

p Idealism denies the objectivity of space and time. Subjective idealists consider them the product of man’s consciousness, while objective idealists claim that they are engendered by the absolute idea, the universal spirit.

p In Materialism and Empirio-Criticism Lenin convincingly demonstrated the insolvency of idealist conceptions of space and time. If, he wrote, we are to believe the idealists that space and time are merely products of human reason, what happens to the incontrovertible fact, proved by science, that the Earth had existed in space and time long before the appearance of man? The Earth has been in existence for thousands of millions of years, while man only for tens of thousands of years! Clearly, this leaves no room for any “creation” of space and time by man or by some mystical absolute idea, or universal reason.

p Pointing to the objectivity of space and time, dialectical materialism also reveals their other most general properties, proceeding from the premise that they are determined by the nature of matter itself. The eternity and infinity of matter thus determine the eternity of time and infinity of space. This means that they have never had a beginning and will never have an end. Modern science penetrates the distant regions of outer space and studies immense periods of time. With the aid of powerful radio telescopes astronomers study material bodies at a distance of thousands of millions of light-years from the Earth. (Light travels at a velocity of 300,000 kilometres per second.) However immense these distances, they are infinitesimally small as compared with the infinite world. Similarly minute, as compared to the eternity of the Universe, are the vast periods of time, measured in thousands of millions of years, which modern geology studies.

p Space as a form of existence of matter is tridimensional, which means that every material body has three dimensions: length, width and height. Correspondingly, bodies can move in die three mutually perpendicular directions.

p In contrast to space, time has only one dimension. That is why all bodies develop in time in one direction only, from 54 the past to the future. Time is irreversible, it moves only forward and it is impossible to revert its movement, to bring back the past. This is a natural fact, yet one which is stubbornly refuted by reactionary Western politicians who endeavour to reverse the course of history and bring back the bygone era of capitalism’s undivided sway in the world. But history cannot be reversed; it is impossible to turn the world of the 20th century in a world of the 19th century. Times are different now and so is the correlation of forces on the world scene. Today there is a mighty world socialist system which upholds peace, democracy, national liberation and socialism, and determines the direction of social progress.

Such are the most general properties of space and time.