I can understand that in the middle of an empty conductor sphere the electric field is worth 0. But I don't understand why it is also 0 in the interior of the sphere at any point. I know that by Gauss' law it is 0 but I don't grasp it. For instance if you chose a point very close to the surface, why is it the same as choosing the middle point? Still by Gauss'law? Well, but then why is the field outside the sphere not 0? If I chose any Gaussian surface outside the sphere, by Gauss' law the electric field should be 0 since there's no charge enclosed. But it is not so. I don't understand why should I enclose the sphere. I could not enclose it if I want not to. Am I mixing things? Like the net flux passing through any Gaussian surface which is indeed 0 outside the sphere if I chose not to enclose it and it is also 0 inside the sphere. I feel I'm all confused about this. I don't know why should I enclose or not a charge when using Gauss law. Another question : Say I have 2 conductor charged spheres. Outside both spheres there exist an electric field, right? But why is the electric field induced by one sphere stopped by the surface of the other sphere? Is it because of Faraday's cage?