London - A mathematician has solved the riddle of why tea dribbles down the underside of a teapot's spout rather than pouring cleanly into the cup.
The spillage is a naturally occurring phenomenon - not the fault of poor spout design, says Prof Jean-Marc VandenBroeck, of the University of East Anglia in Norwich.
The Belgian academic, who for 20 years has specialised in calculating fluid flows, reached his conclusion after dedicating a month to studying "the tea pot effect".