The behavior of particles as waves becomes significant and observable at the microscopic scale, typically on the scale of atoms and subatomic particles. This is the realm where quantum mechanics governs the behavior of particles.
In macroscopic objects, such as everyday objects we encounter in our daily lives, the wave-like behavior of individual particles becomes negligible and is not readily observed. The collective behavior of a vast number of particles in macroscopic objects follows classical physics and can be described effectively by classical mechanics, which does not exhibit wave-like characteristics.
The transition from the quantum realm to the classical realm, known as the quantum-classical boundary, is a topic of ongoing research and exploration in the field of quantum physics. The precise scale at which quantum effects become negligible and classical behavior dominates can depend on various factors, including the temperature, complexity of the system, and the nature of the interactions involved.
In general, larger and more complex systems tend to exhibit classical behavior, while smaller and simpler systems are more likely to exhibit quantum behavior. However, pinpointing an exact boundary between the two regimes is not straightforward and can vary depending on the specific context and experimental setup.
It is important to note that even in macroscopic objects, there are situations where quantum effects can still manifest, such as in superconductivity or the interference of large molecules. However, these situations typically require special conditions or precise experimental setups to observe and study quantum phenomena in macroscopic systems.