Lichtenberg figures/electrical charge and discharge

[Quartile]

What causes the shape of a Lichtenberg figure?

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

[insane_alien]

minute differences in the dielectric breakdown strength and conductivity in the plastic. also where you start the discharge from.

[swansont]

Video of making them

 

and another, made at Fermilab, and an explanation

 

(OK, now I gotta blog about this. edit: done)

[Quartile]

So, in short, the flow of charge follows the path of least resistance.

[insane_alien]

pretty much.