Is the speed of light the fastest measure of speed?

For an example, the speed of light always measures as the constant C when measured locally. Locally means that the measuring instruments experience the same conditions as does the traveling light. This is the case even though objects with mass affect the behavior of light. read more

According to Einstein's special theory of relativity, positive rest mass must travel at less than the speed of light in a vacuum, c. Zero rest mass energy must travel at exactly c. Negative mass, if it exists, must travel at greater than c. Infinitesimally greater would be quite adequate. read more

So in the case of light, no matter where we are, or how fast we are moving, we can see the photon move no faster than the speed of light, because that is the fastest rate of change that can be represented. read more

The speed of light in a vacuum stands at “exactly 299,792,458 metres per second“. The reason today we can put an exact figure on it is because the speed of light in a vacuum is a universal constant that has been measured with lasers; and when an experiment involves lasers, it’s hard to argue with the results. read more