A Routine Fly Ball? (IMAGE) Brown University Caption Researchers at Brown tested the three theories explaining how outfielders judge fly balls. It turns out to be a matter of optical acceleration cancellation. Credit David Silverman/Brown University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.