* Our eyes are constantly moving: Even when we think we're staring straight ahead, our eyes are always making tiny movements to keep our vision sharp.
* Different distances, different movements: When we move our head or body, closer objects appear to move more rapidly than farther objects. This is because the closer objects change their position more dramatically in our field of view.
* Brain's interpretation: Our brains interpret this difference in apparent movement as an indicator of depth. The faster an object seems to move, the closer it appears to be.
Example:
Imagine you're driving down a highway. The trees and houses close to the road appear to be rushing by, while the mountains in the distance seem to move much slower. This difference in apparent movement helps us understand the relative distances of objects.
Why it feels like distant objects are moving with us:
Even though the distant objects are actually moving slightly, their apparent movement is so slow that our brains perceive them as being stationary. This is because we're used to the fast movement of closer objects and our brains subconsciously "cancel out" the slow movement of faraway objects.
In summary:
Motion parallax is a natural phenomenon that helps us perceive depth and distance. While it's an illusion, it's a very effective one that our brains have evolved to use for navigating the world around us.
