> Obviously if it were actual "flow", i.e. diffusion, of ions your reaction times would be a lot slower. The current in cables work similar way - each electron

> Obviously if it were actual "flow", i.e. diffusion, of ions your reaction times would be a lot slower. The current in cables work similar way - each electron moves forawrd and back by small distance, never moving far away from the place it started in. But the information about movement (the elecrtomagnetic field) spreads from one electron to another with the speed of light, so the electrons at the end of cable move as soon as the information gets to them from the begining of the cable. That's why when you press light switch the light starts almost immediately, despite electrons in cables only moving by millimeters per hour.