When I was young, I always went to my grandparents’s home playing, which is near the airport. Each time I stood on the balcony, I can see planes flying through the sky. I asked my mother:”Why is the plane flying so slowly? I think I can run even faster than the plane. Did you say that planes are the fastest transportation in the world?” At the time my mother just told me that is because the planes are too far from us. Soon after that, I had a chance to travel by plane. During the take off and landing processes, I looked outside the window. Through the fast moved trees and buildings on the ground, I get to know how fast the plane was moving. (That is even the slowest speed during the whole flight because it is only the beginning)
The experiences showed above can be illustrated by a psychology concept called motion parallax. Motion parallax is a monocular depth cue arising from the relative velocities of objects moving across the retina of a moving person. It is what we always refer to as the object moving near us seems to move faster than the object moving farther from us.
In the example above, when I sit in the plane, objects on the ground are near to me. We can just assume it as we are near to the objects because motions are all relative. So we feel like the objects move so fast because of the small distance. Assuming that the real flying speeds are the same when it is nearly to land and during the landing period. When we see a plane in the sky, the distance between us and the object is a lot farther than what it is when we are in the plane. Because of the big distance, we feel like the plane moves very slow. But in fact, we know, the real speeds are the same. It is just we have different feelings when observing objects from different distances.
Definition referred to: https://study.com/academy/lesson/motion-parallax-in-psychology-definition-lesson-quiz.html