This is purely a question I know little or nothing about light and the whole EM spectrum for that matter I was just wondering something. Why are visible light waves so puny compared to other frequencies on the EM spectrum. What I mean is that I can send a pulse to an antenna and emit lets say microwaves which travel so far they can be picked up on the moon. Now if I can do that with microwaves why can't I do it with light? When I turn on the light bulb do light waves actually travel thousands of miles through the air only they are so sparse that they cannot be picked up by the human eye? With that question in mind heres another thing I was wondering. Since information can be encoded (modulated) into radio and microwaves can other EM waves be similarly modulated? For example could I broadcast messages over EM waves in the visible light spectrum? I've never heard about gamma rays being used for this either. Sorry for this flurry of questions but heres one last thing I was wondering about waves. Since light waves can be beamed in a straight line as in a laser can other EM waves be beamed like a laser? Could I say beam radio waves to my next door neighbour in a straight line without the possibility of anyone intercepting those radio waves without getting right in front of the radio beam? Could this also be done with longitudinal waves like say sound?