Aussie physicists give cricket a lesson in spin

Twenty years ago, Australia's Shane Warne flighted the "Ball of the Century" that famously bamboozled England's Mike Gatting and reminded everyone of the marvels of leg-spin bowling.
Behind such deliveries lie some powerful principles of physics, a pair of Australian scientists said on Thursday, in a study published just ahead of a new Ashes series.
Not only their team, but also England will be able to benefit from the formulae uncovered -- if they can get past the layers of mathematical equations and graphs, that is.
The study by brothers Ian and Garry Robinson, published in the journal Physica Scripta, provides tools with which to measure the impact of forces like gravity, atmospheric drag, wind and "lift" on the trajectory of a randomly spinning ball.

"The average cricketer could not be expected to fully understand the details of the physics of the paper," co-author Ian Robinson of the University of Melbourne told AFP.
But luckily, a special poster has been prepared with pictures to illustrate the on-pitch meaning of the equations.

And a "user-friendly, interactive version" of the simulation programme is under development for computer, said a statement.
"It should be emphasised that the examples presented in the paper are just that -- examples," said Robinson.
"They do not pretend to provide a definitive answer to questions such as: 'How do I bowl the perfect off-spin delivery?'"

Spin bowlers use their fingers or wrist to put movement into the ball as they release it, causing it to deviate from a straight trajectory when it bounces off the pitch, hopefully fooling the batsman.
Spin balls travel much slower than those despatched by fast bowlers, who seek to deceive the batsman through speed rather than surprise.