I would watch and help (only slightly) my brother Mark solder large vacuum tubes into circuits, all housed in a large homemade plywood box with round holes cut in the front for all the needles and dials.  This monstrosity eventually turned into a HAM radio that was capable of transmitting Morse Code halfway around the world.  I would sit up on the special electronics table, which was actually the laundry folding table, and watch, and get explanations as to how it worked.  He would be installing a clear glass vacuum tube and explain “Now when this filament you see here on this end gets extremely hot, the electrons are jiggling so fast that they fly off of it.”  I could imagine electrons flying off.  He continued “Now the negative electrons are repelled by the positive plate just behind it, so they fly over to these plates you see here on the other end.”  I practically had my eyeball pressed up against the clear glass tube.  “Now you see this wire coil in between where the electrons fly off of and the plates that they are going to?”  He continued.  “That coil in the middle acts like a magnet and bends the beam of electrons up or down depending on the current going through it, thus determining which plate the electrons hit”.  He concluded “It all has to be in this glass tube with all the air sucked out, otherwise the electrons would get blocked by the air molecules”.    

I enjoy it when people don’t dumb things down.  A child might not understand all of it, but they get more than one might think.   Mark eventually got the thing working and used it to communicate in Morse Code to his friend, Greg, a couple of streets over.  That perplexed me slightly.