Can we pass current through air as signals?
Electric current does not really pass through air very well, until the air breaks down and you get a spark. Then it will pass much more easily! You could use a spark to produce a radio signal, and then receive the crackles and pops the spark(s) make, but I dont think this is what you mean. If you mean can you pass a reasonably small current over a long distance, then no you cannot.
