In the double-slit experiment, the behavior of photons (or any other quantum particles) is not dependent on whether they are observed by a human observer or measured by scientific apparatus. The key factor that influences the behavior of particles in the double-slit experiment is the act of measurement itself, regardless of who or what is performing the measurement.
When photons pass through the double-slit apparatus one at a time, they can exhibit wave-like behavior and create an interference pattern on a screen behind the slits. This interference pattern arises due to the wave nature of the particles. However, when a measurement is made to determine which slit the photon passes through, such as by using detectors or other scientific apparatus, the interference pattern disappears, and the photons behave more like particles, creating distinct, non-interfering patterns on the screen.
The act of measurement disturbs the quantum system and introduces interaction with the particles, causing their wavefunction to collapse into a particular state. This collapse is a fundamental aspect of quantum mechanics. It is not specific to human observation but applies to any form of measurement or interaction that extracts information about the particles' properties.
In the context of the double-slit experiment, human observers can act as measurement devices when they extract information about the particles' paths. However, it's important to note that the effect is not specific to human observation but is a consequence of the fundamental principles of quantum mechanics.
In summary, the behavior of photons in the double-slit experiment changes from wave-like to particle-like when a measurement is made, regardless of whether the measurement is performed by a human observer or scientific apparatus. The act of measurement disrupts the quantum system and leads to the collapse of the wavefunction.