If anybody still doesn’t understand, when the wave function collapses, that is called observation. Again, from Wikipedia:
In various interpretations of quantum mechanics, wave function collapse, also called reduction of the state vector, occurs when a wave function—initially in a superposition of several eigenstates—reduces to a single eigenstate due to interaction with the external world. This interaction is called an observation and is the essence of a measurement in quantum mechanics, which connects the wave function with classical observables such as position and momentum.
Physics has this problem with naming things. They use words like “particle”, “observation”, and “spin”, among others, which are words that every English speaker knows, but then they use those words to describe stuff that’s actually only similar to the words everybody knows. This makes physics a lot more approachable for people who know nothing, but then completely confuses people with only a little knowledge.
There isn’t a scientific definition for “observation.” In the Copenhagen interpretation, it really is treated just as vaguely as the colloquial definition, something the physicist John Bell complained about in his article “Against ‘Measurement’”, that the textbook axioms of quantum mechanics are inherently vague because they refer to “observation” or “measurement” which is not itself defined in the axioms. Saying that observation is just “when the wavefunction collapses” is a circular definition and doesn’t answer anything, because then we can just ask, “when does the wavefunction collapse?” and the only answer the textbook axioms give is “when you observe/measure it.”
If anybody still doesn’t understand, when the wave function collapses, that is called observation. Again, from Wikipedia:
Physics has this problem with naming things. They use words like “particle”, “observation”, and “spin”, among others, which are words that every English speaker knows, but then they use those words to describe stuff that’s actually only similar to the words everybody knows. This makes physics a lot more approachable for people who know nothing, but then completely confuses people with only a little knowledge.
There isn’t a scientific definition for “observation.” In the Copenhagen interpretation, it really is treated just as vaguely as the colloquial definition, something the physicist John Bell complained about in his article “Against ‘Measurement’”, that the textbook axioms of quantum mechanics are inherently vague because they refer to “observation” or “measurement” which is not itself defined in the axioms. Saying that observation is just “when the wavefunction collapses” is a circular definition and doesn’t answer anything, because then we can just ask, “when does the wavefunction collapse?” and the only answer the textbook axioms give is “when you observe/measure it.”