The universe contains all of space, time and everything. Currently, the observable universe is 13,799,000,000 ± 21,000,000 light-years across, and makes up 4.9% of the entire universe. However, it's expanding at 299,792.458 kilometers per second, so does it change? No, because our units are ever-so-slightly expanding with it. The universe is currently thought to be 13,799,000,000 ± 21,000,000 years old, yet the oldest star, HD 140283 is thought to be 14,460,000,000 ± 800,000,000 years old. What's up with that? Scientists are finding out it is less and less old than previously thought. A universe could be described as an independent segment of possibility; a bubble of space with a defined beginning point (typically a Big Bang) and a set of physical laws, which may or may not line up with the ones humanity observes. The only thing aside from a vecoverse that can be before the Universe is the Law of Dimensional Cycle.
Most known universes are said to contain an Earth, but in most Multiverse cases there can only exist one Prime Earth where in that concept gives us the idea that reality must exist and branch out from the original reality it started from. This idea, however, varies depending on is creator whether it be a God or simply a scientific process such as Big Bang which was triggered by a Protoverse known to be the absolute smallest building block/verse that can ever be (or at least discovered to be the smallest as science and theories are always on-going in research).
Multiverses
Our universe is contained in a multiverse along with other multiple (and probably alternate) universes - perhaps an immeasurable number - which may or may not contain humans or life at all. In fact, some of them may be so hostile, and chemistry or physics as we know them, may not function properly. The possible total number of universes in our multiverse, based on the probability law, is 10^10^10^122.
Other Information
Travel between universes is possible for extremely advanced civilizations through the use of portals, dark energy, time maneuvering, or other space-warping mechanisms. Additionally, beings like God can traverse through universes easily. Most universes, especially ours, shall eventually "die" as the second law of thermodynamics ensures that energy becomes less and less usable over time. This may not always be the case with alternate physical laws, though. This universe is also the least confusing to understand, as it is the only one that we know exists so far.
Structure
A typical universe starts in a big bang with quantum foam at Planck Temperature, to create space-time. Eventually, this comes together in large numbers to form gluons. These gluons can eventually form into quarks, which create protons and neutrons. Protons come together, sometimes with neutrons, to form atoms, the basic building blocks of all material. These atomic nuclei also form electrons around them to propel against protons. This forms an atom, the basic building block of all material. The first atom is hydrogen, but then helium atoms form. And soon, so do lithium, boron, carbon, oxygen, nitrogen, sodium, and many more! These start forming meteors, then asteroids, and planets. Eventually, some planets grow large, becoming a star. Nearby planets get pulled into orbit, creating a planetary system. This eventually forms star clusters, which form galaxies. These form galaxy clusters, which form superclusters. these form huge cosmic webs, covering about five percent of the observable universe.
Our Address
Apartment 1, 1 Example Road (Example Residence), Example City, Example Province, Example Country, Antarctica, 3 Solar System (Earth), Milky Way Galaxy, Local Group, Virgo Supercluster, Cosmic Web, Observable Universe
See Also