universe is the whole of existing things — all matter, energy, space, and time taken together as a single system — and, by extension, the complete domain of anything considered as a whole.
The word took its modern sense of "the whole world, the totality of existing things" in the 1580s, though Chaucer had used it earlier. It came through Old French univers from Latin universum, "all things, the whole world," the noun use of universus, "all together, whole." Built from unus, "one," and versus, the past participle of vertere, "to turn," it means literally "turned into one" — a word that names everything by naming its unity.
In astronomy the universe is all of space-time and its contents, of which only the 📝Observable Universe can be seen from Earth. The word also narrows by analogy: a universe of discourse is everything a conversation ranges over, and in statistics a universe is the full population from which a sample is drawn. It overlaps with cosmos, which comes from the Greek for "order" and stresses the whole as an ordered arrangement, and with world, which often means only the Earth or the human sphere. A 📝multiverse is a hypothetical ensemble of many universes, including our own. 📝The Marginalian has gathered John Muir's writing on the universe as an infinite storm of beauty and 📝Carl Sagan on why common sense blinds us to the universe.
“When we try to pick out anything by itself, we find it hitched to everything else in the universe.”
"...as sentient beings endowed with awareness, we are 'the universe itself becoming aware.' "
📝The universe conspires for its own benefit. We are the universe; we are 📝One. We formed 📝One Inc as a reminder and practice of that truth, and 📝We Are One gathers how physicists, poets, yogis, and philosophers each say it.