WPCNR VIEW FROM THE UPPER DECK PART II. Observation from News Reports August 9, 2007: A leading density analysis firm announced Monday that today's major league baseballs have harder, denser larger cores than baseballs of 50 years ago, that increase their carry distance 30 feet over baseballs of the 1950s-1970s. Universal Medical Systems, Inc. of Ohio, a leader in density imaging technology, has released a study of density Scans (computed tomography) of baseballs from the Hank Aaron era compared to the baseballs used in the major leagues today that show the difference based on the technology used to analyze rock densities for oil deposits.

Fenway Park, 1998
According to the study, baseball decided to go to a new baseball in 1999, replacing the cushioned cork center with a harder “rubberized pill (center), the addition of polyester in the windings and a very hard synthetic ring or spring.”
The article shows scans of an Aaron-era baseball, and a baseball of the present era (post 2000). The scans show the 2000 baseball core as being more than twice as dense as the ball of the mid-twentieth century. The core of today’s ball is larger, too.
David Zavagno, President of UMS, a firm that manufactures diagnostic imaging technology for veterinary care and geological surveys, stated in the article, “As the CT images demonstrate, the League appartently allowed the composition of the baseball to further change from 1998 to 2001, destroying the integrity of the game’s statistics, including home run records.”
Zavagno said that the sluggers of the late 90s and the early 21st century, regardless of whether they take sterioids or not are hitting a baseball that travels farther and leaves the yard more often as a result.
The methodology used to examine the baseballs is the technology used to examine geological samples for the presence of oil (based on differences of density).
The story can be read at http://www.yubanet.com/artman/publish/printer_62715.shtml