Universe

Universe, as we know, is the totality of existence including Galaxies, Stars, Planets, All Matter Energy.

The observable Universe is only 46 billion light years in radius. Observation of the Universe has led to inference of its earlier stages.

There are many possible theories of the origin of the universe. the most important being the BIG BANG theory.

Etymology

The word Universe derives from the Old French word Univers, which in turn derives from the Latin word universum.

The Latin word was used by Cicero and later Latin authors in many of the same senses as the modern English word is used.

The Latin word derives from the poetic contraction Univorsum — first used by Lucretius in Book IV (line 262) of his De rerum natura (On the Nature of Things)

which connects un, uni (the combining form of unus, or "one") with vorsum, versum

(a noun made from the perfect passive participle of vertere, meaning "something rotated, rolled, changed")

A term for "Universe" in ancient Greece was τὸ πᾶν (tò pán, The All, Pan (mythology)). Related terms were matter, (τὸ ὅλον, tò ólon, see also Hyle, lit. wood) and place (τὸ κενόν, tò kenón). Other synonyms for the Universe among the ancient Greek philosophers included κόσμος (cosmos) and φύσις (meaning Nature, from which we derive the word physics). The same synonyms are found in Latin authors (totum, mundus, natura) and survive in modern languages, e.g., the German words Das All, Weltall, and Natur for Universe. The same synonyms are found in English, such as everything (as in the theory of everything), the cosmos (as in cosmology), the world (as in the many-worlds interpretation), and Nature (as in natural laws or natural philosophy).