causa efecto

"With this installation she dubs Causa-Efecto (Cause and Effect), Spanish artist Ana Soler makes us feel like we're living in The Matrix. Featuring 2,000 tennis balls frozen in mid-air, the installation gives off the illusion that the balls are bouncing of the walls, floors and ceiling of the Mustang Art Gallery in Alicante, Spain. One has to wonder how much time and thought went into placing these balls in their exact positions!"

Source:  My Modern Met