I have a hard time believing that radio wave communication would be used for galactic communications at light speed you would have to wait too long for a message, by the time you got it the info it would be virtually useless.

Imagine this: A planet sends an urgent SOS to one of their battle crusiers ten light years away, ten years later they get the message.

Interstellar communications is going to have to use something different, I don't know what.

But we would be as deaf and oblivious to it right now as Columbus was when he sailed to the "new world" of the radio signals all around him at the time.

You could have been talking on walkie talkies out of his sight and he would not have know it.

Granted such signals at the time were naturally generated, most likely anyway.