Now comes the problem how an ion actually pass through the channel.
We know the membrane is a barrier against ions. Let's quote space's idea:
"consider a plane interface formed by two semi-infinite mediums with
different dielectrics(e1, e2). A charge "q" in medium "e1" at position
z=z1(let's define z-direction as the normal direction toward medium "e1" from
the
intereface) induces a charge distribution on the interface and it feels a
force by the field
generated by the charges on the inter
