Saturn's hexagon change in season. These changes were observed by the Cassini spacecraft. One hypothesis, developed at Oxford University, is that the hexagon forms where there is a steep latitudinal gradient in the speed of the atmospheric winds in Saturn's atmosphere. Similar regular shapes were created in the laboratory when a circular tank of liquid was rotated at different speeds at its centre and periphery. The most common shape was six sided, but shapes with three to eight sides were also produced. The shapes form in an area of turbulent flow between the two different rotating fluid bodies with dissimilar speeds. A
Rebate plane Rebate plane The rebate plane (also known as the rabbet plane) is a hand plane designed for cutting rabbets in wood. It's a simple tool used in many Western countries with hundreds of years of history. It was in use in England at least as early as the 11th century. The rebate plane is one of a group of planes, including the shoulder plane, bullnose plane and carriage makers plane, in which the blade protrudes by a very small amount - usually less than half a millimetre - from the sides of the plane body on both sides. The blade