"Multiverse, a hypothetical collection of potentially diverse observable universes, each of which would comprise everything that is experimentally accessible by a connected community of observers. The observable known universe, which is accessible to telescopes, is about 90 billion light-years across. However, this universe would constitute just a small or even infinitesimal subset of the multiverse."
https://www.britannica.com/science/multiverse
"Multiverse theory suggests that our universe, with all its hundreds of billions of galaxies and almost countless stars, spanning tens of billions of light-years, may not be the only one. Instead, there may be an entirely different universe, distantly separated from ours — and another, and another. Indeed, there may be an infinity of universes, all with their own laws of physics, their own collections of stars and galaxies (if stars and galaxies can exist in those universes), and maybe even their own intelligent civilizations."
https://www.livescience.com/multiverse
"A multiverse is a set of a finite or infinite number of universes, frequently interpreted as a space containing distinct, typically non-interacting universal "bubbles". Occasionally, the term is used to define the hypothetical set of every single possible universe, including the universe in which we live."
https://verse-and-dimensions.fandom.com/wiki/Multiverse
"Physicists have long struggled with a perplexing conundrum: Why do tiny particles such as atoms, photons, and electrons behave in ways that bacteria, bees, and bowling balls do not? In a phenomenon called quantum superposition, for example, individual units (say, of light) exist in two states at once. They are both waves and particles, only settling on one or the other if you specifically test for it."
https://www.popularmechanics.com/science/math/a29339863/quantum-superposition-molecules/
"The more we delve into the cosmic weirdness of quantum mechanics the stranger the world becomes. A state of quantum superposition is being in more than one place, or more than one state, at the same time –a single event can be happening both here and there, or both today and tomorrow."
https://dailygalaxy.com/2020/12/superpositions-the-cosmic-weirdness-of-quantum-mechanics/
"That's all superposition is: quantum States are (abstract) vectors and may be expressed in any basis - which means an infinite choice of superposition for any state."
https://www.physicsforums.com/threads/how-does-quantum-superposition-really-work.1005890/
"In quantum physics, entangled particles remain connected so that actions performed on one affect the other, even when separated by great distances. The phenomenon so riled Albert Einstein he called it "spooky action at a distance." The rules of quantum physics state that an unobserved photon exists in all possible states simultaneously but, when observed or measured, exhibits only one state."
https://www.livescience.com/28550-how-quantum-entanglement-works-infographic.html
"Quantum physics is a field of study that defies common sense at every turn, and quantum entanglement might lead the way in the defying common sense department. Entanglement is the unusual behavior of elementary particles where they become linked so that when something happens to one, something happens to the other; no matter how far apart they are."
https://www.universetoday.com/109525/quantum-entanglement-explained/
"Quantum entanglement describes a strange bond that can form between two particles, even when separated by huge distances. Information about their quantum states can become so inextricably linked that looking at one particle can tell you about the other, and even influence changes in it instantly, no matter how far away it is."
https://newatlas.com/physics/new-distance-record-quantum-entanglement-light-matter/