... A Force from Empty Space: The Casimir Effect . ... Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. ... The form and genesis of dark energy is almost completely unknown, but postulated as related to vacuum fluctuations similar to the Casimir Effect but generated somehow by space itself . ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...