I dont understand how lightning rods work?

Question

okay, ive noticed that at theme parks and schools and public areas they install lightning rods on the roof to suposedly keep away the lightning, so i figured id try to understand how it works, what ive come up with is that lightning is negative and poitive charges colliding and making the spark so they instead of grounding the lightning rods give them a positive charge, since oposites attract and same repel, is that correct? if not how does the lightning rods work?

Answer 1

Ok I'll give you the simple answer

You put a lightening rod on a tall structure to actually attract the lightening bolt. That rod is then connected to a large heavy duty cable that is then connected to the ground

Why do that... that sounds NUTS!

But think of it this way. Lightening wants to get to the ground as fast as possible. that is how it works. You don't want it to hit your house or ride or what not so you put the rod up. The lightening hits the rod and travels down the cable keeping the structure safe

Answer 2

Lightning strikes occur when there is a very strong charge differential available between the ground and (storm) clouds.  The voltage may exceed 600,000 volts which is strong enough to ionize a path from the ground to the cloud.  Imagine that the path starts at a point on the ground and seeks the cloud in several steps where each step is like a straight line moving upwards to a point on a sphere surrounding the point.  None of the steps are in the exact same direction.  This makes a very jaggered path (which is why a bolt of lightning is represented as a jaggered bolt).  The path will start at a high point such as a tree or building roof.  Ionization will start very easily from any pointy object that concentrates the effect at its tip.  After the ionized path is completed from ground to cloud a powerful current of electrons will follow the ionized path to the ground.  It is like the arcing in an electric switch that is suddenly opened.  The lighting rod atop a barn provides a point to encourage the bolt of lightning to initiate from the lightning arrester which has an adequate (copper) cable to safely guide the bolt into the ground.  This prevents the bolt from initiating anywhere else on the roof.  And lightning arrester protects a 45 degree cone shaped area below its tip, except that the point will initiate an ionized path more readily than the ridge of the roof (which is a relatively poor conductor and not pointy).  The lightning always takes the path of least resistance to ground and the lightning arrester provides a safe path.

Answer 3

"Conventional electrical theory" says that current flows from positive to negative. Real current flow is from negative to positive.

A lightening rod attracts lightning. It's entire purpose is to be hit by lightening and not reject it. It is grounded. Since it is so conductive to ground, electrical current takes the "least path of resistance" therefore it sinks the lightning bolt to ground.

It is higher so that is where lightening hits first... it is able to handle enough "amperage" to sink it to earth.

If it was high resistance, it would create "heat" in the area of resistance.

So the bottom line if a lightning bolt hits the edge of a barn, it may see a lot of different resistances between where it hit and going to ground so there is likely heat and then fire.

Putting a lightening rod above the barn will cause the lightening bolt to hit the rod instead of the barn. Lightening rods are usually burned where it is hit.

Lightning rods prevent fires.