Watch a Fascinating Demo of Collisions Inside a Conductor

[pbtami]

I remember seeing a demo of collisions inside a conductor. It was a long board with nails representing the atom positions (a square lattice arrangement) and you would put a hand full of marbles at the top. The marbles will slide down but since they keep hitting the nails the velocity will be constant.
Does anyone have a link to a video showing this demo?
Thanks!

 

[UltrafastPED]

Try "marble electric circuit model.mpg":

 

[pbtami]

Thanks!