Many experiments concerning the determination of the speed of light have been proposed and done. Here two important experiments, Michelson-Morley and Sagnac, will be discussed. A linear moving variation of Michelson-Morley and Sagnac devices will then be proposed for probing experimentally the invariance of the speed of light.

The speed of light has been repeatedly measured considering the time a photon spends travelling from an initial point to another and then coming back to the initial point, the so called two-way speed of light. Experiments aiming to measure the speed of light when it travels strictly an initial point to another, the so called one-way speed of light, have also been proposed. Here we will discuss the conceptual basics some of these experiments, proposing what seems to be a new feasible procedure to measure the one-way speed of light. According to Special Relativity it is expected that the measurable value will match the observed value for the two-way speed of light.