Thought for the month
“To know yet to think that one does not know is best; Not to know yet to think that one knows will lead to difficulty.” Lao Tzu, philosopher (6th century BCE).
Monday, 22 April 2013
Much to Mrs Grange’s delight, Wales thrashed England at rugby last month. The rugby world may want to learn a bit of tribology, courtesy of Sheffield University who have been measuring the dynamic friction between the ball, the skin and the fingerless gloves or mitts that some players wear. Most rugby balls are made with pimples on the surface to improve handling. In dry conditions with no mitts, balls with more closely spaced pimples were better for grip. But in wet or muddy conditions, the density of the pimples allowed a film of moisture to form between them, so when wet, a ball with wider pimple spacing is better. Synthetic leather mitts produced the best performance across all conditions as the imposed texture interlocked best with the pimples on the ball.