Re: Charged disk; was electrostatig

[Leigh Palmer <palmer@SFU.CA>]

> No, I do not disagree; you can make a disk which is more or
> less cylinder-like. My intuition suggests that a cylinder with
> very sharp edges will have most of its Q near the edges.

I don't see why you say that. Do you believe that there should be
any important difference arising in the charge distribution on a
1 cm long, 1 cm diameter cylinder if its edges go from 1 nm radius
of curvature to 10 nm? My intuition tells me that there will be no
important difference.

> The S(r) distribution will be like a delta function. But why
> should my intuition be trusted? I am only saying that a real
> disk is not a mathematical cylinder.

I believe the mathematical solution results in a convergent
fraction of the charge on, say, the outer ten percent of the
area of the disc. John's simulation suggests a finite charge
density resides in the center.

Leigh