The origin and motion of Earth have long been subjects of debate within the scientific community. From the 18th-century French biologist Buffon's theory of comet collisions to Kant's hypothesis of meteorites and Laplace's nebular hypothesis, each theory has its merits but fails to provide a complete explanation. With the advancement of modern aerospace science, more and more phenomena of celestial bodies colliding have been observed, making Buffon's comet collision theory a possibility once again.
Earth's motion is equally enigmatic. It not only revolves around the Sun in an elliptical orbit but also rotates on its axis. These movements are not uniform; they are constantly changing. The rotation speed is gradually slowing down, while the revolution speed varies due to changes in the orbital shape. The axis of rotation is also unstable, wobbling like a top in a conical motion on the plane of Earth's orbit, causing the point it points to in the sky to change continuously.
These complex movements make Earth an "aging and weak" mover, tirelessly traversing the cosmos. One cannot help but wonder how Earth initially began its motion. What will its future trajectory look like? What is the source of energy for Earth's motion? Is there such a thing as a "prime mover"?
These questions remain unresolved mysteries, awaiting further exploration by scientists.
