"The superposition principle is the idea that a system is in all possible states at the same time, until it is measured."
http://physics.gmu.edu/~dmaria/590%20Web%20Page/public_html/qm_topics/superposition/superposition.html
"The feature of a quantum system whereby it exists in several separate quantum states at the same time."
https://jqi.umd.edu/glossary/quantum-superposition
"The superposition principle is a hallmark of quantum theory which emerges from one of the most fundamental equations of quantum mechanics, the Schrödinger equation"
https://phys.org/news/2019-09-atoms-quantum-superposition.html
"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/
"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/
"Superposition is essentially the ability of a quantum system to be in multiple states at the same time — that is, something can be “here” and “there,” or “up” and “down” at the same time."
https://uwaterloo.ca/institute-for-quantum-computing/quantum-computing-101
"Superposition is a confounding yet foundational principle of quantum physics in which a quantum system—for example, a group of subatomic particles or atoms—can exist in multiple quantum states simultaneously."
https://www.accessscience.com/content/demonstration-of-quantum-superposition-using-record-breaking-large-molecules/BR1023191
"The question of superposition only arises in the world of subatomic particles. In that realm of existence, the laws of classical physics seems to stop working entirely. The principle of quantum superposition states simply that a quantum particle can exists in 2 distinct locations at the same time."
https://becominghuman.ai/quantum-superposition-and-what-that-means-to-quantum-computation-3fbb5a711b9a
"But in recent years, physicists have scaled up their experiments, demonstrating quantum superposition using larger and larger particles. Now, in a paper published Sept. 23 in the journal Nature Physics, an international team of researchers has caused molecule made up of up to 2,000 atoms to occupy two places at the same time."
https://www.livescience.com/2000-atoms-in-two-places-at-once.html