What If The Speed of Light is Not Constant?
One of the most fundamental physics facts is that the speed of light in a vacuum is constant for all observers. But can we really be sure that the speed of light wasn’t different in the past, or perhaps in other parts of the universe?
2023-07-19 22:00:00 - PBS Space Time
In fact, variable speed of light theories have long been used to try to explain everything from dark energy to gravity itself.
Let’s explore how constant this fundamental constant really is.