The nature of the wave-particle duality and the collapse of the wave function in quantum mechanics is a complex and often debated topic. I'll try to provide a simplified explanation to address your questions.
In quantum mechanics, particles such as electrons or photons can exhibit both particle-like and wave-like properties. The behavior of these particles is described by a mathematical entity called a wave function, which contains information about the particle's properties, such as its position, momentum, and other observable quantities.
When a measurement is made on a quantum system, the wave function collapses into one of the possible eigenstates corresponding to the observable being measured. This collapse is often associated with the act of observation, where an observer interacts with the system and obtains information about it. This is known as the observer effect or measurement problem.
However, it's important to note that the collapse of the wave function is not solely dependent on the act of observation by a conscious observer. In quantum mechanics, any interaction between a quantum system and its environment can lead to wave function collapse. This interaction is referred to as decoherence.
Decoherence occurs when a quantum system interacts with its surrounding environment, which includes things like other particles, electromagnetic fields, or any other sources of interaction. These interactions cause the quantum system to become entangled with the environment, leading to a loss of coherence and the collapse of the wave function.
The exact mechanism of wave function collapse and the role of observation versus environmental interactions is still a subject of active research and interpretation in quantum mechanics. Different interpretations, such as the Copenhagen interpretation, many-worlds interpretation, or the consistent histories interpretation, provide different perspectives on how to understand and interpret the collapse of the wave function.
It's worth mentioning that the wave function collapse is a fundamental aspect of quantum mechanics, and while there are various interpretations, the precise underlying mechanism is still an open question in the field.