The generalized Maxwell equations in vacuum are basically the same with Dirac's extended Maxwell equations, although intrinsic charges and currents are defined by the time differential and gradation of scalar fields, respectively. Consequently, the electromagnetic stress-energy tensors make important conservation laws. Then, we found scalar fields acting like the gravitational wave interacting with the electromagnetic wave. Interestingly, those gravitational waves due to the scalar fields push out the electromagnetic waves. Moreover, there is a possibility of the existence of the materials, from which we feel no gravitational forces although the electromagnetic waves are kicked out by those gravitational waves. We also discussed about the relation with weight.