As the title says - Why does the speed of light have a maximum speed limit? In the outer space the medium that transmits lights is as close as possible to what we call "nothing", though not really nothing in the physicists sense. The nature of space should determine the rate of transmission through it, right? Does empty space being close to a perfect vacuum limit the speed of light? Objects exist in space, so space must also be an object, and it must in some measureable way excert influence on the speed of light. Is there a hypothesis on the reason why the speed of light has an end limit to its speed and what limits it? Or is its speed considered a "given" for now?