In the double-slit experiment, the behavior of particles such as photons can indeed be influenced by the act of observation or measurement. This phenomenon is known as the observer effect or the measurement problem in quantum mechanics.
In the double-slit experiment, when particles, such as photons, are directed towards a barrier with two slits, they can exhibit both wave-like and particle-like behaviors. When the particles are not observed or measured during their journey from the source to the screen, they display an interference pattern, indicating their wave-like nature. This pattern arises from the constructive and destructive interference of the waves passing through the two slits.
However, if one attempts to determine which slit the particles pass through by introducing a measurement device or observing the particles during their path, the interference pattern disappears, and the particles behave more like individual particles, creating a pattern of two distinct bands behind the slits.
The act of observation or measurement disrupts the quantum system and collapses its wavefunction, forcing the particles to "choose" a definite state. This collapse into a specific state is often referred to as wavefunction collapse or the collapse of the probability distribution. The interaction between the particles and the observing machine can indeed cause an interruption or disturbance that leads to a loss of interference and a return to particle-like behavior.
It's important to note that the precise mechanism behind wavefunction collapse and the relationship between the observer and the observed system are still topics of debate and interpretation in quantum mechanics. Various interpretations, such as the Copenhagen interpretation and the many-worlds interpretation, offer different explanations and perspectives on this phenomenon.