Particles possess a wave function that collapses to a specific eigenvalue upon measurement, leading to the question of whether macroscopic objects, like tables, exist in a collapsed state or remain part of a non-collapsed quantum wave function. The discussion highlights that while individual particles cannot have precise values for both position and momentum, macroscopic objects behave classically due to averaging effects over many particles, making quantum uncertainties negligible. Decoherence is presented as a key concept explaining why macroscopic objects do not exhibit superpositions of distinguishable states, as it renders such superpositions unobservable rather than causing actual collapse. The conversation also touches on the implications of decoherence for understanding the wave function of the universe and the nature of measurement in quantum mechanics. Overall, the emergence of classical behavior from quantum mechanics remains a complex and debated topic.
