Tufts University physicist Roger believes the recent increase in the number of home runs coincides with the dawn of the "steroid era" in sports during the mid-1990s, and that the surge quickly dropped to historic levels in 2003 when Major League Baseball instituted steroid testing.
"A change of only a few percent in the average speed of the batted ball, which can reasonably be expected from steroid use, is enough to increase home run production by at least 50 percent," he said.
Tobin acknowledges athletes today achieve at a higher level than did athletes of the past, and that, along with other factors, could affect major league batting.
"Physics cannot tell us whether a particular home run was steroid-assisted, or even whether an extraordinary individual performance indicates the use of illicit means," said Tobin.
But he said analysis of the physics, combined with physiology, "suggest that some suspicion is reasonable."
The research is to be published in an upcoming issue of the American Journal of Physics.