- #1
Old Guy
- 103
- 1
Homework Statement
I'm working with a 0ne-dimensional random walk and looking at Fick's second law, below. All I've read seems to take D = 1/2 as a given for ordinary diffusion, but where does this come from? Is there a way to derive it?
Homework Equations
[tex]
\frac{\partial }
{{\partial t}}p\left( {x,t} \right) = D\frac{{\partial ^2 }}
{{\partial x^2 }}p\left( {x,t} \right)
[/tex]