@@Recent experiments for proton radius measurement, based on muonic hydrogen confirmed that the proton size obtained by muon interaction is 4% smaller than the standard value. This results generate a new problem that was called “the proton size puzzle”. The author believes that this occurs because the proton radius changes, depending on the particle with which it is interacting. In this context the author proposes that the standard proton radius be defined in conditions, where a proton is isolated in space, without interacting with any other particle. In this condition the standard proton radius seems very close to the value obtained in muonic hydrogen experiments. If this new standard proton radius value be admitted, one solution to the "proton size puzzle" must answer two basic questions: a) Why the proton increase it size when interacting with an electron in a hydrogen atom? b) Why the proton maintain the (new) standard radius value, when interacting with the muon to form a muonic hydrogen atom? The question (a) can be answered, in a context where the electric force that arises between the opposite charges (of the electron and the proton) may be affecting the proton and expanding its radius. Considering the Heisenberg uncertainty principle, with the proton as "observer" of the electron position, the proton also not will "know" where the electron position is. Thus the proton is simultaneously attracted to all positions where the electron might be positioned, which are defined by the orbital wave function. Thus the uncertainty principle could explain that the proton is subjected to a radial force field, which tends to increase its size. Another solution for the proton size puzzle, proposed by the author, considers a change in the physical interpretation of the orbital wave functions. These functions are currently associated probability density of the presence of the electron in a given volume of space. In this new interpretation, the wave functions equations are the same, but its final values (that can be expressed in C/m3) can be associated with an effectively density of electric charge, that exists simultaneously, composing a negative charges membrane which are distributed in space around the atomic nucleus, as defined by the orbital wave function charge densities. This new model has been called by the author as “Electron Membrane Paradigm” (EMP), because in it the “electron particle” is turning into an “electron membrane”. The EMP has the potential to solve the proton size puzzle, and allowing the emergence of new theories, that can model both, electrons and other particles, in the form of strings and membranes.