In this blog post, we’ll explore the role of vortices in our daily lives and, in particular, how they relate to the flight of a golf ball.
When fall arrives, images of colorful foliage, reading, and fall sports days come to mind. Most of us have probably had the experience of sprinting across a wide playground as children, only to trip over a large rock lying there and fall. Similarly, when air flows rapidly through the atmosphere and encounters an “obstacle” like an airplane, its flow becomes significantly disrupted. If you’ve often watched airplanes flying through the sky, you’ve likely seen clouds swirling in the wake of an airplane’s passage. In fact, this phenomenon occurs in the airflow surrounding most flying objects. If you could make a golf ball as big as an airplane and throw it into the sky, you’d likely see clouds swirling around it as well.
The nature of these swirls is precisely the phenomenon known as vortices. A vortex refers to the phenomenon where air swirls in a direction different from its original flow due to the rotational motion of a fluid. While this may seem like just one of the simple characteristics of air, it actually has a significant impact on various aspects of our daily lives.
Once you understand the concept of vortices, it’s easy to view them as a somewhat negative phenomenon. In fact, vortices are often a nuisance—not only in research and experimentation but also in everyday life. A prime example is the automobile. When a car travels at high speeds, the airflow behind the vehicle becomes severely disrupted, creating vortices. These vortices increase aerodynamic drag and affect the vehicle’s performance and fuel efficiency. Given the importance of a car’s performance, automotive engineers have developed various devices to reduce these vortices. A prime example is the rear spoiler, mounted on the edge of the roof or on top of the trunk, which regulates the airflow behind the vehicle to reduce vortices. Furthermore, since vortices can cause errors in the precise measurement or analysis of fluid motion, they represent one of the key challenges researchers must address.
However, the phenomenon of vortices has two sides, much like “Janus” from Greek and Roman mythology. This is because vortices, which are often considered a hindrance in automobiles, can actually play a very useful role in other contexts. Consider the sight of golfers hitting a ball on the course. If no vortices were generated around the golf ball, it would not fly as far as it does now and would land at a much shorter distance. There is an interesting scientific principle at work here—one that even golf legend Tiger Woods doesn’t consciously think about every time he swings. So, how exactly do the vortices around a golf ball help?
These vortices are created by the dimples on the surface of the golf ball and help it travel farther. Distance is a crucial factor in golf. Of course, accuracy is also very important, but anyone who enjoys golf knows well that distance and accuracy are closely related. When golf first began, players used balls with smooth surfaces. However, they discovered that balls with natural scuffs—resulting from repeated use—actually flew farther, and subsequently, golf balls with uniform dimples on their surfaces were developed to take advantage of this characteristic. This evolved into the dimples found on today’s golf balls.
What is the difference between a smooth ball and a dimpled ball? When a smooth ball rises into the air and cuts through the air as it flies, it creates a large low-pressure area behind it. This creates a significant pressure difference between the front and back of the ball. Air converges at the front of the ball, increasing pressure there, while pressure decreases at the rear, causing the ball to experience a force pulling it backward. This force acts as drag, or resistance from the air. Consequently, a smooth ball without dimples experiences significant air resistance throughout its flight, causing its speed to decrease rapidly.
In contrast, as air flows over the surface of a dimpled ball, it creates small vortices within the numerous dimples. These vortices help prevent the airflow behind the ball from breaking away easily, thereby reducing the low-pressure area. As a result, the pressure difference between the front and back of the ball decreases, leading to significantly less air resistance than a smooth ball. Simply put, the vortices behind the golf ball act to keep the airflow attached to its surface. Thanks to this principle, a dimpled golf ball can fly farther and more stably with the same amount of force.
As such, vortices play both beneficial and harmful roles in everyday life. In the past, vortices may have been viewed merely as a disruptive phenomenon. However, through countless studies and experiments, humanity has come to understand that vortices are not simply something to be eliminated, but rather a phenomenon that can be actively harnessed. Just like the dimples on a golf ball, properly utilizing vortices can significantly improve performance, and this principle is widely applied in various fields, including aircraft, automobiles, and ships. In this way, science has advanced through the process of accurately understanding and utilizing natural phenomena, and research that transforms unfavorable factors into new possibilities will continue into the future.
