Could the universe's fundamental speed limit actually be changing?
While textbooks teach that the speed of light in a vacuum is a fixed constant, some physicists are investigating whether this cosmic limit has fluctuated in the past or varies across different regions of space.
The speed of light, or 'c', is officially defined as exactly 299,792,458 metres per second in a vacuum [S3:p2]. It acts as the universe's ultimate speed limit for all material particles and signals, and serves as the vital link between mass and energy in the equation E = mc2 [S3:p2, S3:p3].
However, exploring variable speed of light theories could reshape our understanding of gravity and dark energy [S1:p1]. If the speed of light is not stable, the implications for cosmology and astronomy are profound; such a change could alter the strength of the electromagnetic force, the density of nuclear matter, and the very strength of molecular bonds [S2:p1, S2:p2].
Source: What If The Speed of Light is NOT CONSTANT?
