Hey everyone, I'm going over my course content for an exam this Saturday and I'm a bit confused by a realisation I've just had. In a metallic waveguide we know there are no TEM modes. But wouldn't this mean that we couldn't see through metallic waveguides as we see electromagnetic radiation? Obviously this only applies when the waveguides are perfect conductors, but I don't think this is the reason either because we can assume it's at least a 50% perfect conductor and thus should lock 50% of the light. Any insight?