(9) Why Must Space Around Observers Move in a Cylindrical Spiral Pattern According to the above physical definition of time, if space around an observer doesn't move, that observer would have no sensation of time. In the real world, there has never been a person without a sense of time. This inversely proves that for all people, for observers in any spatial region, their surrounding space must always be in motion. What causes the motion of space around objects? This is a profound question, explained in unified field theory as follows: Physics is our description of the geometric world (composed of objects and space), so any physical phenomenon must correspond to a geometric state. The motion states we describe in physics correspond to perpendicular states in geometry. Without human description, motion states are actually geometric perpendicular states. Note: This is partly reasoning - while motion states always correspond to geometric states, assuming which geometric state corresponds to motion requires hypothesis. Unified field theory explains object and space motion using the Perpendicular Principle, stated as: Relative to our observation, for any object in the universe, at any space point around it, a maximum of three mutually perpendicular lines can be drawn. This is called space's three-dimensional perpendicular state. Any space point in this perpendicular state must move relative to our observation, and its continuously changing motion direction and trajectory can form a new perpendicular state. This is a qualitative description of the Perpendicular Principle. In unified field theory, there's also a quantitative description. The quantitative description mainly specifies the relationship between object motion velocity and surrounding space's solid angle. This derivation is profound and complex - interested readers can search for Unified Field Theory Version 7. Motion with continuously changing direction must be curvilinear. Circular motion can have at most two mutually perpendicular tangent lines. Since space is three-dimensional, any point along its motion trajectory must have three mutually perpendicular tangent lines. Therefore, motion must extend in the direction perpendicular to the circular motion plane. The reasonable view is that space points move in a cylindrical spiral pattern (the combination of rotational motion and linear motion perpendicular to the rotation plane). Everything in the universe, from electrons, photons, and protons to Earth, Moon, Sun, and galaxies - all objects freely existing in space move in spiral patterns without exception, including space itself moving in a cylindrical spiral pattern. The spiral motion law is one of the universe's core laws. Everything in the universe appears to move cyclically, but not in closed loops. The superficial cause of object motion is force; at a deeper level, it's caused by space's own motion. Objects exist in space, and their positions move due to space's own motion. This explains why all objects in the universe must move.