Why is the speed of light the 'cosmic speed limit'?

One of the foundational axioms of the theory of relativity is the existence of an invariant speed: a speed that is the same for all observers. As it turns out, particles with no rest mass, such as the photons of light, travel at this invariant speed in a vacuum. read more

But Einstein showed that the universe does, in fact, have a speed limit: the speed of light in a vacuum (that is, empty space). Nothing can travel faster than 300,000 kilometers per second (186,000 miles per second). What's more, only light can travel at this speed. read more

But neutrinos are no gauge particle of a field (like Photons or Gravity), so it is possible that the vacuum speed of light is the speed at which fields in the universe propagate, and other phenomena are limited by it - and field-free phenomena not. read more