Shoe shops sell a variety of shoe sizes to accommodate a variety of foot sizes—but what if both the shoe and foot size depended on how it was measured? Recent developments in quantum theory suggest that the available values of a physical quantity, such as a foot size, can depend on the type of measurement used to determine them. If feet were governed by the laws of quantum mechanics, foot size would depend on the markings on a foot measure to find the best fit—at the time of measurement—and even if the markings were changed, the measurement could still be precise.
source https://phys.org/news/2021-02-experimental-measurement-dependent-realities.html
