In the double-slit experiment, the behavior of electrons (or any other particles) is often described using wave-particle duality. When a single electron is sent through the double slits, it passes through one of the slits and creates an interference pattern on the detector screen, suggesting wave-like behavior. However, when we observe or detect the electron at the screen, it appears as a localized particle at a specific location.
The question of whether an electron goes through both slits simultaneously before detection is an intriguing one. According to the standard interpretation of quantum mechanics, the act of measurement or observation collapses the electron's wavefunction into a definite state. This means that upon observation, the electron is forced to behave like a particle and can only be detected at a specific location.
The phenomenon of wavefunction collapse is still a subject of debate and different interpretations of quantum mechanics provide various explanations for it. The Copenhagen interpretation, which is one of the commonly taught interpretations, suggests that the wavefunction collapses upon measurement due to the interaction between the quantum system (the electron) and the measuring apparatus (the detector). The collapse determines the outcome of the measurement, and the electron is found at a specific position.
It's important to note that our understanding of the behavior of quantum systems is based on experimental evidence and mathematical models. While the wave-particle duality and wavefunction collapse have been observed and verified in numerous experiments, the underlying mechanisms at play are still a subject of ongoing scientific investigation.