A friend of mine was telling me about a storm that knocked down a power line over at their place, and it got me to thinking. Why are downed power lines dangerous? I don't see any good reason for it.
It seems to me that if they can put a GFI on a hair dryer that will kill power within a fraction of a second if it falls into the sink or tub and shorts out, they ought to be able to do the same thing to a power line. Is there any reason why the basic concept can't work at that scale? Or if not, why aren't they standard equipment on power lines?