Science
One formula, one photograph, and the fact that belongs to that formula alone.
Smooth Until Proven Otherwise
Water pouring from a tap can be modelled by equations whose viscous form emerged in 1822 and 1845. Variants of the same continuum framework underpin modern fluid engineering. Yet for one fundamental three-dimensional case, nobody has proved that every smooth start stays smooth forever.
8 min read
The Last Step of Every Breath
Air is moved by pressure. Blood is moved by the heart. But the final micrometres into a living cell have no pump behind them — only random motion and a difference in concentration.
6 min read