The Economy as a Hydraulic Machine   

In the 1940s Bill Phillips, crocodile trapper, failed sociologist, electrical engineer, war hero and finally Keynesian economist, designed and made one of science’s wonders; a hydraulic machine that demonstrates the movement of money around the economy.

It is not exactly an example of self-organised criticality because the water flows are controlled, but it is an example of matter forming new stable states and of avalanche behaviour. Red-coloured water splashes through tanks and pipes labelled income, taxes, consumption spending, foreign trade sector and so on, its passages controlled by the operator, resting in new stabilities that explore  various forms of economic activity.

Reading list

Models, the Third Dimension of Science’ edited by Soraya de Chadarevian and Nick Hopwood
‘How Nature Works’ Per Bak
‘The Creation’ Peter Atkins