Dont stand under trees in a thunderstorm...

[GRUNHERZ]

http://forums.dpreview.com/forums/read.asp?forum=1034&message=9556370

[lada]

cool pictures thanks



btw...  overhere, its one of first things you will learn at nursery school

i belive its common all around world



but realy cool pictures

[Capt. Pork]

Originally posted by lada
btw...  overhere, its one of first things you will learn at nursery school  

Shame you weren't home sick that day.

[FUNKED1]

I miss living in tornado country.  Can't remember the last time I saw lightning out here.

[GRUNHERZ]

Originally posted by FUNKED1
I miss living in tornado country.  Can't remember the last time I saw lightning out here.

Quite rare, but I remeber some small storms with ligtning  here in the last few years..

[Tarmac]

Are you guys kidding?  Is lightning an inland thing?

[xrtoronto]

Trivia: Lightning occurs when the attraction between the negative charges at the bottom of the cloud and the positive charges on the ground is strong enough. The lightning we see is actually the return stroke; when he positive charges move up to the cloud.

[Holden McGroin]

A lightning discharge consists of electrons which have been stripped from their molecules flying through the air. They are accelerated by a strong electric field, a consequence of the big voltage difference between the cloud and the ground. They crash into air molecules on their way down and free other electrons, making a tube of ionized air.
 


The "leader", the first stroke of a lightning discharge, actually proceeds in steps -- lengthening by about 30 meters at a time, taking about a microsecond (one millionth of a second) to do each step. There is a pause between steps of about 50 microseconds. The whole process may take a few milliseconds (one-thousanths of a second), providing enough time to perceive motion. Most of the charge flows after this leader makes electrical contact with the ground, however. A powerful "return stroke" releases much more energy. That's not the whole story, however -- a lightning flash may have only one return stroke or may have several tens of strokes using the same column of ionized air. It may seem to flicker.

[AWMac]

Cuz dem friggen squirrels will pisss on ya!:D

[capt. apathy]

every time I hear of a lightning strike incident (usually involving people dumb enough to hide under a tree), I think of the "wonder-bat" episode of the Simpson's.

"I found myself stuck in a thunderstorm.  so covering my head with a sheet of steel, I ran for the shelter of the biggest tree on the hill. . . . when I came to..."

[majic]

Originally posted by xrtoronto


Trivia: Lightning occurs when the attraction between the negative charges at the bottom of the cloud and the positive charges on the ground is strong enough. The lightning we see is actually the return stroke; when he positive charges move up to the cloud.

You sure about that?  Isn't it a negative charge?

[xrtoronto]

Originally posted by majic
You sure about that?  Isn't it a negative charge?

majic, I just googled this for you...

C&P

A Lightning Bolt

The structure of a typical lightning bolt is surprisingly complex. It begins with a large thunderstorm. Through a process that is not yet fully understood, charge separates within the cloud, causing the top to become positively charged and the bottom negatively charged. This negative charge attracts a "shadow" of positive charge on the ground below. When enough charge accumulates, a lightning bolt occurs.

A lightning bolt happens in a series of stages. First, a faint step leader emerges from the base of the cloud. It moves toward the ground in steps of 50 meters or so, pausing very briefly between steps. Often it branches as it goes down, which is why so many lightning bolts "fork". When the step leader nears the ground, it attracts "streamers" of positive charge from the ground. When it finally connects with one of these streamers, a brilliant return stroke occurs as the charge drains out of the ionized channel left by the step leader. The charge nearest the ground goes first, causing the return stroke to propagate upward. Often this is followed by another relatively faint cloud-to-ground dart leader, which is rapidly followed by another return stroke. This process can take place up to 40 times, which is why many lightning bolts are seen to flicker.

source

[xrtoronto]

Originally posted by capt. apathy
every time I hear of a lightning strike incident (usually involving people dumb enough to hide under a tree), I think of the "wonder-bat" episode of the Simpson's.

it's probably that people were just seeking shelter from the rain by standing under a tree during a storm...I guess alot of people don't realize that if lightning does hit a tree, it vapourizes the sap inside the tree, turning it to steam and instantly causing the tree to explode under the pressure of expanding gas

...I thought I had seen all the Simpson's episodes, but I don't remember the 'wonder-bat' one

[Otto]

There's nothing wrong with standing under a tree as long as it's not the only tree in the area.  If you're in a forest of 5000 trees, STAY THERE!  1:5000 odds are pretty good compared to you running out into a field where you become the highest object and the odds change to 1:1.

[majic]

Right.  So, what I was questioning was what type of charge was moving from ground to cloud.  And since it's electrons (which have a negative charge) that are flowing, then it would be a negative charge being carried up to the cloud.  Am I wrong?