No, a macroscopic body, such as a fridge, is not identical to the wave function of its constituent particles. The wave function describes the quantum state of a system, including the probabilities associated with different properties of the particles that make up the system. It provides information about the particle's position, momentum, energy, and other observable quantities.
In the macroscopic world, where classical physics dominates, the behavior of large objects is well described by classical mechanics rather than quantum mechanics. Classical mechanics deals with the motion and interactions of macroscopic bodies based on concepts such as mass, position, and velocity. The laws of classical mechanics, such as Newton's laws of motion, are effective in describing the behavior of objects at macroscopic scales.
While macroscopic objects are ultimately composed of quantum particles, the collective behavior of the particles leads to emergent classical properties that are not directly described by individual particle wave functions. The interactions and statistical behavior of a large number of particles give rise to macroscopic phenomena that can be effectively described using classical concepts.
For example, a fridge is made up of countless particles, such as atoms and molecules, interacting with each other. The behavior of the fridge, such as its temperature, pressure, and macroscopic motion, is described by classical thermodynamics and fluid dynamics, which are based on macroscopic variables and laws.
However, it's important to note that there are some situations where the quantum nature of macroscopic objects becomes relevant, such as in superconductivity and Bose-Einstein condensation. In these cases, collective quantum phenomena can manifest on macroscopic scales, but they typically require specific conditions and low temperatures.
In summary, while macroscopic bodies are composed of quantum particles, their behavior is generally described by classical mechanics and macroscopic laws, rather than the individual wave functions of their constituent particles.