On the Gravitational Field a Suggestion about a Possible Experimental Research

After a preliminary discussion of the relevance of the field nature of grav-itation interaction, both for the fundamental interaction of particles and the topology of space time, a method is proposed to produce and detect a dynamical gravitational field, allowing the determination of the order of magnitude of its propagation velocity. From the actual point of view of the physicist the structure of space and time is merely depending on two fields: the electromagnetic and the gravitational fields. On the other hand mathematically electromagnetism is entirely described inside the Poincaré groups (enlarged Lorentz group), i.e. in the ambit of the special relativity, whereas the gravitational field requires the consideration of the larger set of transformation of general relativity. For this and others more subtle reasons our knowledge of electromagnetism from one side and of gravitation from the other presents itself in a quite different way. The very notion of field has been introduced by Faraday in the ambit of his theory of electromagnetism, and formalized then by Maxwell. Electromagnetic waves as such have then been produced and seen in laboratory by Hertz. Eventually it has been seen that electromagnetic waves of Hertz's length are produced in nature and that such waves fill the universe. In the meantime a lot of very important things were happening in Physics: the atomic theory of matter was put on new more solid basis, the electron and the nuclei of the atoms were discovered and most important quantization was discovered. To the purposes of our discussion we have to notice that the only force which had to be considered to give a completely (with the exclusion of few " minor " details) satisfactory theory of the structure of the atoms, molecules, solids and so on was the electromagnetic force. Even later, when nuclear physics and physics of elementary particles were becoming of uttermost importance, new forces and new fields were hypothesized, but always neglecting the gravitational forces. Gravitation was considered instead only in the ambit of cosmology, astronomy and geophysics. There was however the fundamental progress made by Einstein (see Ref. [1] and [1']), who introduced the new idea that gravitational forces and inertial forces were manifestations of the same field. This new idea allowed the generalization of the special relativity.