THE rise of data visualisation in the digital age has revived interest in a style of chart called a Sankey diagram. These were initially made famous by Charles Joseph Minard's statistical graphic of ...

Doing 'work' is the scientific way of saying that energy has been transferred. For example, a grazing cow, a firing catapult and a boiling kettle are all doing 'work', as energy is being transferred.

Sankey diagrams summarise all the energy transfers taking place in a process. Sankey diagrams are drawn to scale - the thicker the line or arrow, the greater the amount of energy involved. You may be ...