On Sun, 07 Jun 2009 10:39:03 +0100 (BST) someone who may be "Dave
Liquorice" wrote this:-

Others have mentioned DC or AC at 25kV. How far will 25Kv jump in dry air?

Not very far. However, there is a difference between laboratory
conditions, where such things are measured using precise devices,
and the outside world where safety distances are set [1].

I was surprised by how close he got to the line without an arc, but
it was presumably dry air.


[1] in the outside world the energised conductor and thing near it
may be moving, as well as the air and the ground being damp. There
is also the question of voltage gradients in the ground.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54