curvature

In the first of the movie's many striking images, we share his majestic view from the top, the curvature of the planet and the glow of the horizon brilliantly reflected in his helmet.

A turtle drawing an ellipse would have to turn more per distance traveled to get around its “pointy” sides than to get around its flatter top and bottom. This notion of how “pointy something is,” expressed as the ratio of angle turned to distance traveled, is the intrinsic quantity that mathematicians call curvature.