Casimir Force (IMAGE) University of California - Riverside Caption Measuring only around one-tenth of a millimeter, the tiny ball seen in the image is pulled toward a smooth plate (unseen but positioned above the ball in this configuration), in response to the energy fluctuations in the vacuum of empty space. The attraction between the ball and the plate is the Casimir effect. Credit U. Mohideen, UC Riverside. 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.