14 March

A beautiful example of penetration in action. The perfect way to understand migration. "Now imagine the world as a giant vat subdivided into a number of smaller containers (nations) separated from each other by semipermeable membranes (borders). Instead of salt, provide each container with differing amounts of food, shelter and essential services. In this scenario, population flow from nation to nation will be a direct function of the degree of difference of goods, opportunities and hope."