Imagine this: you're on the 18th hole, the game is intense, and your putt could decide it all. You take aim, steady your nerves, and send the ball rolling towards the hole. It seems perfect, but then, in a cruel twist, the ball teases you by dipping in and then, just as cruelly, pops back out onto the green. This phenomenon, known as the 'lip out', has intrigued golfers and scientists alike, and now, new research led by the University of Bristol has delved into the physics behind it.
The 'lip out' putt is a peculiar occurrence that affects golfers of all skill levels. It's when the ball hits the edge of the hole but, instead of dropping in, it rolls away, leaving you frustrated and wondering what went wrong. Emeritus Professor John Hogan, from the School of Engineering, Mathematics, and Technology at the University of Bristol, decided to apply his expertise in mechanics to unravel this mysterious phenomenon. The study, published in Royal Society Open Science, offers an intriguing insight into the world of golf and the science behind it.
Professor Hogan has affectionately dubbed these rebellious golf balls the 'golf balls of death', drawing a parallel to motorcycle riders performing the daring 'wall of death' stunt. "We approached this from a mechanical perspective," Professor Hogan explained. "We've identified two distinct types of 'lip outs'. The first is the 'rim lip out', where the center of mass of the golf ball remains above the level of the green, and the second is the 'hole lip out', where it does fall below."
At the core of both types of 'lip outs' is a delicate balance, a 'degenerate saddle equilibrium', as Professor Hogan describes it. It's a state where the golf ball is precariously perched on the rim of the hole, neither fully in nor safely on the green. The 'rim lip out' occurs when the ball rotates around the top of the hole at a fixed angle and velocity. A slight perturbation, like a grain of sand or a gentle breeze, can determine whether the ball stays on the green or drops into the hole.
The 'hole lip out', on the other hand, is a rarer occurrence, happening only under specific conditions. Professor Hogan elaborates, "Here, the golf ball falls into the hole and undergoes a pendulum-like motion as it rolls along the wall. Its potential energy is converted into spin, and if it doesn't touch the bottom, it can return to the rim and back onto the green."
So, what's a golfer to do? Easier said than done, as Professor Hogan's friends in the golfing world would attest. "They tell me 'lip outs' happen when you hit the ball too hard," he says. "Our research suggests aiming as close to the center of the hole as possible and approaching the rim with minimal speed. That way, the ball has just enough momentum to tip into the hole, but not enough to carry it around the rim and back onto the green."
Professor Hogan's work focuses on mechanics, studying the motion of objects under the influence of forces. Sir Isaac Newton's Laws of Motion, once used to understand planetary movements, are now being applied to sporting scenarios, offering a unique perspective. This research builds on Professor Hogan's previous work, where he has applied mechanics to understand the physics of skateboarding and the motion of a basketball after it hits the hoop.
This study not only adds to our understanding of golf but also highlights the fascinating ways in which scientific principles can be applied to everyday activities. It's a reminder that even in the world of sports, there's always more to uncover and explore. So, the next time you experience a 'lip out', remember, it's not just bad luck—it's physics at play!
