Photographer: Crossing the blue
Title: Luan Swart
This image shows how the stars relatively and concentrically move around the North Pole, and how the stars inline of the axis of the Earth basically look like they are standing still. This phenomenon happens because relative to where you stand on Earth you rotate different diametrical distances as the Earth rotates, the closer you are to the poles the smaller the diametrical distance you cover becomes. If you move away from the poles towards the equator, the diametrical distance you cover increases. When looking up at the stars they move according to the same point of reference. This means that the axis is stationary (and also the centre of the circles). As you move away from the axis, the star trails become longer and create concentric circles around the centre. The easiest way to view this is to think that the stars in the centre of the circle, which barely moved, were photographed just as long as the stars on the far edge of the photo, which moved a large distance. The red lines crossing through the image are airplanes on their respective routes around the globe, now taking into account the relative movement of the earth around its own axis and the curvature of the earth, these airplanes would never have been able to fly in such accurate directions (observe how perfectly parallel the lines are to each other) without the invention of the GPS.