A very attractive feature of the theory of general relativity is that it is a perfect example of a “falsiable” theory : no tunable parameter is present in the theory and therefore even a single experiment incompatible with a prediction of the theory would immediately lead to its inevitable rejection, at least in the physical regime of application of the aforementioned experiment. This fact provides additional scientiic value to one of the boldest and most fascinating achievements of the human intellect ever, and motivates a wealth of efforts in designing and implementing tests aimed at the falsifcation of the theory. The first historical test on the theory has been the detection of light gr- ing the solar surface (Eddington 1919): the compatibility of the theory with this first experiment together with its ability to explain the magnitude of the perihelion advance of Mercury contributed strongly to boost acceptance and world wide knowledge. However technological limitations prevented physicists from setting up more constraining tests for several decades after the formulation of the theory. In fact, a relevant problem with experimental general relativity is that the predicted deviations from the Newtonian theory of gravity are very small when the experiments are carried out in terrestrial laboratories.