Pictured: Circa 1922. Bill Hughs, Jr., son of Bill Hughes of the Rochester Hustlers (later to be renamed the Rochester Red Wings in 1928), stands on a baseball field wearing a baseball uniform and holding a ball.

The Magnus effect is a physical phenomenon that can be observed when a rotating spherical object moves through a fluid (did you know air can be classified as a fluid?!).

The rotation of the object affects the way that the fluid moves around it, creating pressure differences that result in a force perpendicular to the direction of the object’s motion. This force is called the Magnus force, named after Heinrich Gustav Magnus, a German physicist and chemist who lived in the 19th century and observed/documented the phenomenon in 1852.

The way a player grips (from the side) and throws a baseball can affect the spin of the ball, and subsequently the curve of the trajectory. Players will make the ball spin left-to-right, or right-to-left, depending on which hand they use when throwing.

These two factors can put a spin on the ball, which continues in the direction of the grip used. Gripping to the side, and spinning the ball away from the pitcher’s body causes air to move faster on the side of the ball inside the pitcher’s body, resulting in lower air pressure and higher air pressure on the side of the ball outside the pitcher’s body, where air is moving more slowly. The high-pressure air wins out and pushes the ball in the direction of the low pressure, creating the curve across the pitcher’s body.

Altitude, temperature, and humidity all affect curveballs as they affect the air density of a game.