> Why do overhead cables never flap around in the wind?

Actually they do, it's just it's usually very fast and very low amplitude 
flapping.  Imagine holding out a stretched violin string in the wind, it's 
not really going to flap is it?

Anyway, take 200 metres of this stuff (which I make weighs 10 tons):

http://www.csunitec.com/saws/new-river-band-saw.html

pull it *very* tightly between two points (I estimate you're going to need 
at least 60 tons of tension in the cable), and then put it in the wind, I 
can't see it flapping about too much personally.  Some of the really long 
cables have dampers on them to get rid of the main resonant frequency, a bit 
like what they put on the Millennium Bridge in London to stop it resonating 
at the frequency people walked at.

> Come to think of it, why doesn't rain short out power cables?

Because air with rain in it is still an insulator?

> Steelworks. They have furnaces hot enough to melt steel, right? So what 
> THE HELL is the furnace itself made of?!

Lots of things have higher melting points than most steels.  Ceramics for 
instance.

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