Reminds me of a bet I made a long, long time ago. :-)
I had a friend who collected antique radios, as did I.
We were talking about the possibility of sending wireless power and what it would entail.
I bet him I could within two hours construct a device to send power over a distance of 100 yards to a receiver that would convert it to direct current while using absolutely no electrical parts at the sending location. And it would also transmit data to the receiver using Morse code.
He considered it for a while and said it would be worth losing the bet just to see such a contraption...lol
I made a simple oscillator using a low-power 555 timer IC hooked to a small speaker. I hooked this gizmo to a 100 watt solar panel and duct taped the whole outfit to the side of a shed that was in shade.
I then constructed an ugly, makeshift frame from 2x4 stock that held a small mirror that could swivel on two dowel pins. The mirror was made semi rigid to the frame using two rubber bands. Then I connected a piece of string to the mirror so that a makeshift wooden morse key would deflect it when pressed. I aimed the rig so it would cast sunlight onto the solar panel only when the Morse key was pressed... then I sent the morse equivalent of hilarious laughter to my surprised friend standing by the gizmo taped to the shed wall.
I still have the old Philco Tombstone radio :-)
I had thought about such things some time before when asked how to most simply send data to an orbiting satellite. I came up with several methods that took no electronic equipment at all and also allowed the person sending data to get a reply. The methods were extremely interesting and once they were explained were so simple that anyone could immediately see that they would indeed work.
Bump
I like these old Philco farm radios as they have permanent magnet speakers that you can drive from the audio out on a PC or an mp3 player. Most AC powered radios from that era (early 30's) had electromagnetic coils as the speaker magnet that needed to be powered before the speaker could function.