Normally, these changes are too subtle to notice.
Under certain conditions, the effect becomes obvious.
This can produce mirages in which distant objects appear to float, stretch, or become distorted.
The famous floating appearance of distant ships or landforms can sometimes be explained by these variations in atmospheric density.
The same basic principle helps explain why something
seen over water may appear to occupy a position that does not correspond exactly to its physical location.
What the eye receives is real light.
The apparent location and shape of its source can be altered by the atmosphere through which that light has traveled.
The Brain Adds Another Layer to the Mystery
Physics alone does not completely explain why such an image can feel so extraordinary.
The human brain is constantly interpreting visual information.
Most of the time, this happens so quickly that we never notice it.
