Assume a radio wave with wavelength 1 m is traveling in the negative z direction when it encounters a grid of closely spaced wires (say, 10 cm separation) laying in the xy plane, with each wire running parallel to the y-axis and electrically isolated from each other wire. For the moment let's additionally assume the EM wave is polarized such that the electric field oscillates back and forth in the y direction, aligned with the wires.
In this scenario I understand the EM wave will cause the electrons in the wires to oscillate in the +/- y direction, giving rise to a y-polarized light wave in the reverse direction, ultimately reflecting the incoming wave back in the +z direction.
Now let's adjust the scenario and assume the wave is polarized such that the electric field oscillates back and forth in the +/- x direction, perpendicular to the wires. In this case, although the EM wave might create a temporary voltage difference between the different wires, there is no place for the electrons in the wires to flow, so there will be no current and no reflected EM wave (and the initial light wave will just pass through the grid of wires and travel on its merry way). Is that correct so far?
Finally, as in the last scenario, the radio wave is polarized in the +/- x direction and the wires run in the +/- y direction, but now we assume that (far away, out of range of this radio wave's area of impact) the wires are electrically connected by a simple perpendicular wire. My question is, what happens to the EM wave in that situation?
I'll share my speculation mainly to expose my level of ignorance: As the radio wave encounters the grid of wires, the E-field sets up an oscillating potential difference between the wires. Since the wires are electrically connected far away, there will be a current. For any pair of wires at a given moment, current will be directed in the +y direction along one wire and the -y direction along the other wire, and with a current in the +/- x direction along the joining wire far away. The wires running in +/- y direction would emit waves 180 degrees out of phase with each other, (and therefore no actual energy carrying radiation would be reflected by them), but the joining wire far away would emit a wave polarized in the x direction, essentially reflecting the EM wave but also moving the location of the light ray origin over to the joining wire.
What's the actual result?
