Quantum mechanics, when examined closely, poses some deep questions about reality. These questions often take the form of thought experiments, which are later (usually much later) followed up by real experiments. One of the most difficult and deepest of these is a thought experiment proposed by Eugene Wigner in the 1960s, called “Wigner’s friend” (you don’t want to be Wigner’s friend). Now, much later, Wigner and his friend have been formalized and extended. The result sets us up with a contradiction: either reality is a lot stranger and less real at the level of quantum mechanics, or quantum states cannot possibly exist at large scales… More about this article in the link below…
https://arstechnica.com/science/2020/08/quantum-reality-is-either-weirdly-different-or-it-collapses/
