ORIGINAL: BMatthews
It's hard to go back and say what the original reason for dimples on golf balls was. But there's no doubt that they have a number of effects. One, as Sport Pilot said, is to aid in the generation of lift up or to the side through aiding the Coanda effect when a spin is imparted on the ball. However other factors weigh in as well such as the delay in airfow separation which is the real topic of this thread.
read and learn, (yes it is a cut and paste, but all this conjecture is driving us nuts) dimples are not there to keep them from rolling of gentle slopes either
Dimples first became a feature of golf balls when a certain Taylor patented a dimple design in 1908. Other types of patterned covers were in use at about the same time, including one called a "mesh" and another named the "bramble", but the dimple became the dominant design due to "the superiority of the dimpled cover in flight".[6]
Most golf balls on sale today have about 250 – 450 dimples, though there have been balls with more than 500 dimples. The record holder was a ball with 1,070 dimples — 414 larger ones (in four different sizes) and 656 pinhead-sized ones. All brands of balls, except one, have even-numbered dimples. The only odd-numbered ball on the market is a ball with 333 dimples, called the Srixon AD333.
Officially sanctioned balls are designed to be as symmetrical as possible. This symmetry is the result of a dispute that stemmed from the Polara, a ball sold in the late 1970s that had six rows of normal dimples on its equator but very shallow dimples elsewhere. This asymmetrical design helped the ball self-adjust its spin-axis during the flight. The USGA refused to sanction it for tournament play and, in 1981, changed the rules to ban aerodynamic asymmetrical balls. Polara's producer sued the USGA and the association paid US$1.375 million in a 1985 out-of-court settlement.
The United States Patent and Trademark Office's patent database is a good source of past dimple designs. Most designs are based on Platonic solids such as icosahedron.
Golf balls are usually white, but are available in other high visibility colors, which helps with finding the ball when lost or when playing in low-light or frosty conditions. As well as bearing the makers name or logo, balls are usually printed with numbers or other symbols to help players identify their ball.