I've been trying to get my head around Polarisation and how it achieves orthogonality. I'm not sure if this should be in Physics or Electrical Engineering Section. (Mods can move this where appropriate) I know that 2 EM wave with linear polarisations where one wave is shifted by π, they would interfere. But, if we now have those 2 same waves and assign opposing polarisations to each (1 wave with Horizontal Polarisation and the other with Vertical Polarisation), would this π shift still interfere, or they would be completely orthogonal to one another? --- Or basically give me an entirely new wave with the polarised vector additions?