Cause of Lightning: What is the Real Explanation?

[Utter Novice]

First apologies for asking what is in all probability a misconceived question, but here goes.

The accounts of the cause of lightning seems to explain it in terms of turbulence in high clouds causing ice particles to become electrically charged by bumping into each other.

But this seems incorrect to me; there can surely be no charge created by substances of the same type colliding with one another.

Have I missed the point? If so (or indeed if not), how are charges in clouds created?

 

[schip666!]

I think the usual explanation is that molecules "rub against" one another and electrons are pulled off. This is the same as running a comb through your hair or shuffling your feet on a carpet. The electrons "stick" to one of the objects and accumulate until you touch a doorknob or your friend.

 

[Utter Novice]

Thanks schip666. But my confusion is still in place. My understanding was that a charge can only be created if a substance rubs against another substance with a different triboelectric characteristic, hence there is a net transfer of electrons. But if particles of ice collide in the turbulence of a cloud, there can be no such net transfer because (definitionally) ice has the same triboelectric characteristics as itself.

I am sure I have something wrong here, but I don't know what!

 

[ZapperZ]

You might want to read this article:

http://physicsworld.com/cws/article/news/39381

Zz.