The moon illusions involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.
The illusion is an optical illusion and is caused by the way the human brain perceives size and distance.
Factors such as the presence of foreground objects, the size of the Moon in relation to other objects in the sky, and the relative distance of the Moon from the viewer can all contribute to the illusion.
Despite the fact that the Moon’s size does not actually change, it can appear to be much larger when it is near the horizon than when it is high in the sky.
Table of Contents
- How does the Moon Illusion work?
- Versions of the Moon Illusion
- Illusions like the Moon Illusion
- Discovery of the Moon Illusion
- References and Resources
- Sign up for emails from Mental Bomb
How does the Moon Illusion work?
The moon illusion works by the way our brain perceives size and distance.
When the Moon is near the horizon, it is often seen in the context of familiar, nearby objects such as buildings and trees.
Our brain uses these familiar objects as a frame of reference to judge the size of the Moon, which can make the Moon appear larger.
Additionally, our brain uses the relative size of objects to judge their distance.
Because the Moon is often seen alongside other objects in the sky such as stars, when it is high in the sky, our brain perceives it as being farther away, which can make it appear smaller.
The combination of these two factors, the presence of nearby objects and the relative size of the Moon in relation to other objects in the sky, can make the Moon appear larger when it is near the horizon than when it is high in the sky.
Versions of the Moon Illusion
The following are some versions of the Moon Illusion
Illusions like the Moon Illusion
The Moon Illusion is a size constancy illusions in which the perceived size of an object is affected by its surroundings. Some examples of size constancy illusions include:
The Ebbinghaus illusion: This illusion is similar to the Delboeuf illusion but in this case the central circle appears larger when surrounded by smaller circles and smaller when surrounded by larger circles.
The Delboeuf illusion is a perceptual illusion in which the perceived size of a circle is affected by the size of the surrounding circles.
The Occlusion illusion is a visual illusion where an object that is partially obscured by another object appears to be farther away than it actually is. This illusion is caused by the brain’s interpretation of the relative depth of the objects based on their relative size and position. This phenomenon is based on the visual cues that the brain uses to perceive depth, such as relative size, position, and overlap.
The Müller-Lyer illusion is a classic example of size-contrast illusion, in which two lines of equal length appear to be different due to the presence of arrowheads or fins at the end of the lines.
Ponzo illusion: This illusion involves the perception of an object appearing larger or smaller depending on the size of the surrounding context.
All these illusions demonstrate that the perceived size of an object can be influenced by the context in which it is presented, and that the brain uses the size of the surrounding objects as a reference point to judge the size of the central object.
Discovery of the Moon Illusion
The phenomenon of the moon illusion has been known for thousands of years and has been described by many ancient cultures.
The earliest known written reference to the moon illusion is found in ancient Chinese texts from around 400 BCE. The ancient Greek philosopher Anaxagoras also wrote about the illusion in the 5th century BCE.
In the Western literature, the earliest known scientific explanation of the moon illusion was provided by the Greek philosopher and scientist Aristotle in the 4th century BCE.
In the modern era, the moon illusion was studied by the philosophers, scientists and psychologists. One of the most notable contributors to the scientific understanding of the moon illusion was the German psychologist Hermann von Helmholtz in the 19th century.
He proposed that the illusion was caused by the way the brain perceives size and distance.
In 20th century many other scientists and psychologists, such as George Müller, have contributed to the understanding of the moon illusion and have proposed various theories to explain it.
References and Resources
Check out our complete list of illusions.