lattice grid
connections
balls in place when p=0.63
 
PERCOLATION MODEL
Physicists make models.
 Put the balls on a lattice grid

Put either a metal or a glass ball in each square of a grid
 Balls are ``connected'' to a ball above, below, right and left
 We want the sample to have top to bottom and right to left connections to conduct electricity  diagonal does not work in the standard model
 A ball would be metal with probability p between 0 and 1.0 and p_c
is the critical value above which the sample is conducting
 We find this on a computer by calculating a random number between 0 and 1.0 for each square.
We test if some p is the right one by checking which sites have metal balls by observing
if our random number is less than the trial p if it is we put a metal ball there. If not a glass ball would go there.
Lets try p=1.0  is there percolation?
Lets try p=0  is there percolation?
What is the smallest p that works for our square grid???

