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What is the universe?
4 Answers
- Michel VerheugheLv 75 years agoFavorite Answer
By definition, the universe is everything we can observe. In practice, it means: the observable universe between two horizons: the past and the future one.
The past horizon is that of galaxies moving away from us at a speed greater than that of the light. (Yes, it is possible if you include expansion).
The future horizon is that of galaxies the light of which hasn't reached us yet.
As Stephen Hawking writes in one of his books: if we discover something before or beyond our universe, it would become, by definition, part of it.
- Donut TimLv 75 years ago
The Universe is all of time and space and its contents. The Universe includes planets, stars, galaxies, the contents of intergalactic space, the smallest subatomic particles, and all matter and energy.
