One of those annoying-to-those-who-know-better shortcuts that movies and TV shows sometimes take is the visual trope of throwing a piece of wood (or a rock) at an “electrified fence” and producing an exciting shower of sparks. Typically, one character is just about to touch the fence, only to be pulled back just in time by another character who throws something at the fence to show the first character how they almost bought it.
It looks good — everyone loves a good sparking. In fact, you may have noticed how many action scenes take place in factories that seem mainly to manufacture sparks and steam. You may have noticed how often welders seem to be creating showers of sparks in the background of every action movie.
But this isn’t about our love of sparks.