The idea of light leaving our universe and returning to it is purely speculative and lies outside the realm of current scientific understanding. It is not supported by any known physical laws or theories. Therefore, it is challenging to provide a definitive answer to what would happen in such a hypothetical scenario. However, we can explore some possibilities based on general principles.
Uncertainty: If light were to leave our universe and return, it would imply that it has encountered phenomena or regions beyond the boundaries of our known universe. These regions, by definition, would be outside the realm of our current understanding. Consequently, it is uncertain what the properties and dynamics of such regions might be and how they would interact with light or any other physical entities.
Speculative Scenarios: In the absence of concrete scientific theories about what lies outside our universe, one can only speculate about potential outcomes. Here are a couple of speculative scenarios:
a. Alteration of Light: Light might experience modifications, distortions, or interactions with unknown entities or forces outside our universe. These alterations could impact the properties of light itself, such as its wavelength, energy, or direction.
b. Violation of Physical Laws: It is possible that the physics outside our universe operates under different laws or principles altogether. In that case, the behavior of light may differ significantly from what we currently understand. It could exhibit unexpected phenomena or behave in ways that defy our current understanding of light and the laws of physics.
Philosophical Considerations: The concept of light leaving our universe and returning raises philosophical questions related to the nature of our universe, its boundaries, and the existence of realms beyond it. These questions touch upon topics such as the nature of reality, the limitations of human perception and knowledge, and the boundaries of the observable universe.
It's crucial to emphasize that these speculations are highly speculative and hypothetical. As of now, our scientific understanding is limited to the observable universe, and we do not have direct evidence or theoretical frameworks to explore what lies beyond its boundaries.