On Sun, 25 Sep 2011 08:46:38 -0400, "Robert Green"
wrote:

"micky" wrote in message

stuff snipped

I dunno. I distinctly recall seeing a program about a flood and people
watching from a tall hotel building. When the water reached a certain
level, the horns of the cars in the hotel parking lot began sounding.

Why would watert short the horn relay, but not short out the battery
so the horns couldn't sound. Why wouldn't the headlights go on, and
the trun signals, etc. Why the horn?

Beats me. All I remember is the survivors making a point of how eerie it
sounded in a hotel without power and not much noise when the car horns
started going off in the rising waters, one after the other. Then they
starting gurgling as the water reached the horn's diaphragm and finally went
silent. I know they're relay controlled so I suspect that's the component
that caused the horns to sound. How, I couldn't say.

Perhaps the weight of the water on the steering wheel horn button is
what made the horns sound.

I'd rate that scenario "not likely" I'm afraid.

While I believe that most door and window circuitry is rubber-booted and
generally weatherproof,

I'm not saying anything is weatherproof, just that copper conducts
electricity better than even dirty water.

That doesn't matter, though, in something like a PC circuit board or perhaps
even a relay. That's why so many cellphones die when dumped in the sink or
worse. Flood waters on city streets are probably a hell of lot more
conductive than clean water.

Another question related to this I have long entertained. Why does
throwing the radio or electric heater in the bathtub kill the person
in the tub? At least in the movies. Why doesn't the current go
through the dirty bathwater to the metal drain, and from there to
ground, in the days when some drains were metal. Why would enough of
it go through someone's body?

I think I first saw that in a James Bond film 50 years ago. (-: It sounds
like the Mythbusters might have tackled something like that already. I sure
as hell ain't doing the research!

That's the trouble. I can never get a volunteer. And I myself am
very busy this week.

If this does happen, I wonder if people pick up the heater and hold it
as they toss it from the tub, making their body a required part of the
path to ground. Wwhen they would be better off getting out of the
tub while leaving the heater, etc. in it.

Clearly questions for the theoretical physicists of the group.

And Tony, you've heard of washing computer keyboards in the
dishwasher?

No soap, NO HEAT on the DRYing part of the cycle.

They say it works well.