In the double-slit experiment, the behavior of photons (or other quantum particles) can exhibit characteristics of both particles and waves. This phenomenon is known as wave-particle duality. The behavior of photons is not dependent on the specific observer being a human or a scientific apparatus. Rather, it is influenced by the act of observation or measurement itself.
When photons are not observed or measured, they can exhibit wave-like behavior, creating an interference pattern as they pass through the double slits, indicating their wave-like nature. This pattern suggests that the photons can simultaneously take multiple paths and interfere with each other.
However, when an attempt is made to observe or measure which path a photon takes (for example, by placing detectors near the slits), the interference pattern disappears. Instead, the photons behave more like particles, exhibiting a pattern consistent with individual particles passing through one of the slits. The act of observation or measurement disturbs the wave-like behavior and collapses the wavefunction, leading to the manifestation of particle-like behavior.
It's important to note that the term "observation" in this context refers to any interaction that gathers information about the quantum system, not just observations by conscious human observers. The interaction can occur through various means, including scientific instruments, detectors, or any other measurement apparatus.
Therefore, the behavior of photons in the double-slit experiment is influenced by the act of observation or measurement, regardless of whether it is done by human eyes or scientific apparatus.