First, when the blades are arranged around the outside edge. The photo is a shot of the container ten seconds after spinning commences. The outer edge where the blades are located is rotating, but the middle area isn't moving at all. The only way to transmit the rotation of the outside edge to the middle is the viscosity of the water, but strangely enough, the viscosity of water is quite weak. Using the present blade setup, it would take as much as an hour to get all the water to rotate only by viscosity.