The expansion of the universe is a concept related to the overall growth of the fabric of spacetime itself. It is important to note that the expansion of the universe does not violate the principle that nothing can travel faster than light within spacetime.
The expansion of the universe is governed by the theory of general relativity, which describes how the fabric of spacetime can stretch or contract due to the distribution of matter and energy. However, the expansion itself does not involve objects moving through space faster than the speed of light. Instead, it is the expansion of space itself that causes the distances between galaxies or clusters of galaxies to increase over time.
To put it in perspective, the expansion of the universe is not like objects moving away from each other at speeds greater than the speed of light within the existing spacetime, but rather the creation of new space between objects. This means that the expansion of the universe does not provide a mechanism for faster-than-light travel within the fabric of spacetime as we understand it.
The principle that the speed of light is an upper limit for the motion of objects within spacetime is a fundamental tenet of special relativity. As of our current understanding, it remains valid, and no experimental evidence or theoretical framework has been established to suggest otherwise.
It is worth mentioning that while faster-than-light travel is not supported by our current understanding of physics, scientific research continues to explore the frontiers of knowledge, and new discoveries or theoretical breakthroughs could potentially reshape our understanding in the future. However, any such developments would require robust empirical evidence and consistent theoretical frameworks to support them.