The moire phenomena can be defined as the macroscopic periodic effect obtained by the superposition of two microscopic structures which, individually, produce no macroscopic effect. This phenomena has been used empirically since a long time to observe phenomena invisible with the nacked eye. For instance if one superimposes on a microscopic reference structure a similar but deformed structure the moire effect enables us to visualize the nature of the deformation. Interferometry is fundamentally a Moirg effect: the macroscopic interference fringes are the result of the moire effect between the two microscopic phase structures (in space time) of the light waves. We can in this case notice that the microscope effect operates also on the time coordinate: when we observe interference fringes we look at the projection, on the plane of observation and during the reacion time of the detector, of the two four-dimensional-structures, each of which is completely undetectable by our eyes.