The Magnus Case

The Magnus effect originates from the person who first observed it. H.G. Magnus was the first to experimentally investigate the effect in 1853. This German physicist and chemist was responsible for discovery of the effect which puts “curve” on a spinning object like a golf ball, tennis ball, or baseball. The Magnus effect generates a force on a spinning cylindrical or spherical solid submerged in a liquid or gas when there is a relative motion between the spinning object and fluid. However, Newton in fact was the first to recognize the effect. Newton saw that when a tennis ball hit by an oblique racket, it would curve. Bernoulli also discovered that as speed of a fluid is increased, its pressure decreases, which is part of the Magnus effect. These principles all affect the spin of a baseball, and its movement as well.

People have debated whether a curveball actually curves or if it is an optical illusion. It was established after fast photography captured the movement of the baseball, proving that it in fact does curve. Physics professors began to question why a curveball curves and used the Magnus effect to prove the reasoning. A spinning object moving through a fluid, in this case a baseball, leaves its straight path because of pressure differences that progresses in the fluid from the velocity changes which is persuaded by the spinning object.

When a baseball is thrown, it drags some of the air around with it as it is spinning. The air is rushing by on all side of the baseball. The drag of the side of the ball in which the ball is traveling slows the airflow, while the opposite side of the ball has drag that accelerates the airflow. Greater pressure on the side where the airflow is slower forces the ball in the direction of the low-pressure region on the other side, where a relative increase in airflow occurs.

The Magnus effect formula is expressed by FMagnus Force=KwVCv, where FMagnus Force is the Magnus Force, K is the Magnus coefficient, w is the spin frequency measured in rpm, V is the velocity of the ball in mph, and Cv is the drag coefficient. The Magnus coefficient is a constant number in the equation, spin frequency is the number of times the ball rotates around an axis, and the drag coefficient is the representation of air resistance of either side