lightning conductor

[cheater99]

can anyone explain how a lightning conductor works.
surely once an aerial has a good earth via a conductor it becomes more attractive for the lightning to hit,
or does it help reduce the upward charge from the aerial.
which is what apparently happens before a strike?

[Mortartube]

The whole idea is that the lightning rod is more attractive to the lightning than the building to which it is fixed. It is a highly conductive path to take any lightning hit down the outside of the building to earth, rather than allowing lightning to travel through the more resistive building itself and cause damage.

The more resistive a material, the more difficult it is for the electricity to pass through it and more heat is generated by higher resistances, so more damage is likely.

http://en.wikipedia.org/wiki/Lightning_rod

[dozeydo]

I'm not sure about whether aerials act as lightning conductors, but once, years ago, in a storm, I took the aerial out of the TV and put it on the floor. There was a flash of lightning and a large spark shot out of the end of the aerial wire which jumped off the floor. The same bolt blew the tube of next door's TV whose aerial was fixed to the party wall. So maybe they do. It scared the dog and me anyway!