Yes, scientists have the ability to control and observe whether a photon behaves as a particle or as a wave in laboratory experiments. This phenomenon is known as wave-particle duality, and it has been extensively studied in the field of quantum mechanics.
Experimental setups, such as the double-slit experiment, have been designed to investigate the wave-particle nature of photons and other quantum particles. In the double-slit experiment, a beam of photons is directed towards a barrier with two closely spaced slits. When the photons pass through the slits and hit a screen, they create an interference pattern characteristic of waves. This suggests that photons exhibit wave-like behavior.
On the other hand, if the experiment is modified to detect the arrival of individual photons at the screen, it is found that photons behave as discrete particles, producing a pattern consistent with particles.
By manipulating the experimental conditions, such as the choice of measurement apparatus or the arrangement of detectors, scientists can selectively observe the particle-like or wave-like behavior of photons. This demonstrates that the behavior of photons can be controlled and influenced in laboratory settings.
It's important to note that this wave-particle duality is a fundamental aspect of quantum mechanics and is not unique to photons. It applies to all elementary particles, including electrons, protons, and atoms, although the specific experimental setups may differ depending on the particle being studied.