A sketch of the balance of forces responsible for the tides (above) and of the resulting force field which creates the ocean tides (below). The force diagram above is an enlargement of the situation of the earth when it is in a position relative to the sun indicated by the red line. Note that the earth's orientation in space remains the same, so all points on earth perform a circular movement on circles of equal radius. (The earth's centre moves along the gold coloured circle,while the point labelled A on the earth's surface moves on the white circle; both have the same radius.) This produces the same centrifugal force for all points. The sun's attractive force, on the other hand, varies with distance from the sun. See the text for further explanation.