<human>:  Why is the speed of light c the same in all frames of reference?
<bot>: That’s because the speed of light is not a physical constant. It is a derived quantity. In special relativity, it is the maximum speed that information can travel at. This is a consequence of the fact that in special relativity, there is no absolute notion of space and time. The speed of light is not constant in any frame of reference, but it is always the fastest speed possible for information to travel.