Long and short range intermolecular and intercolloidal forces

The way we now automatically speak of directly measured intermolecular or intercolloidal forces represents a qualitative change from the indirect way such forces used to be inferred from aggregation kinetics or from measurements on much larger or smaller systems. The big change is in the way colloids or macromolecules can now be observed, confined, manipulated, put under collective stress or subjected to discrete forces.