What is Moon Illusion? How Moon Illusion occurs? All about Moon Illusion: TechFlecks

How Moon Illusion occurs?

Topics covered:

What is Moon Illusion?
Why moon appears bigger at horizon and small in night sky?
How Moon Illusion occurs?
All about Moon Illusion,
All about Ebbinghaus illusion, 
All about Ponzo Illusion, 
All about Convergence Microspia explained in details.

You might have realized how big the full moon looks whenever it's low on the horizon than something when it is high in the sky.    Until prehistoric days, studies have attempted to explain about such a odd influence, and shockingly, we don't yet have a decent answer, but it is not so just because we don't try. 

Aristotle

, 

Leonardo da Vinci

, 

René Descartes

, 

Ptolemy 

 some of the finest minds in science, also have battled with all of this topic and struggled to produce a lasting. Among the first theories proposed was that the representation of the thing in the sky above the horizon is actually larger. Then maybe the environment of the Planet behaves as a giant magnifier.

One such description, however, does not really fix this. Because refraction done by the earth's atmosphere might make the moon look smaller whereas we are talking of its magnification so, it's actually not worthy to talk such an explanation . And as well as, it also doesn't vary anyway if you literally calculate that size of apparent moon at various locations. So then why, does it always seem bigger only at the horizon?  It must have been an visual illusion. But, actually why and how?  Let's explore it!

In Ebbinghaus illusion,  according to which two similar objects appear differently due to the size of the things they are surrounded with, may be a reason. Perhaps the moon appears bigger near the horizon as, in the view, it will then be relatively small trees, buildings, and hills. However when it is further up, the immense black of the night sky covers it and seems small by contrast.

The famed 

Ponzo illusion

 would be another option. According to this, while drawing a perspective, the lower objects which are near the horizon has to be drawn bigger than those up and at far distances.  Now  , looks like we've cracked the riddle of moon illusion around both the illusions, however, sadly, there are several specifics that create confusion. Over one thing, if it's just the Ebbinghaus effect, also for aircraft which is above cloud, one should consider the moon illusion to vanish because there would be no more relatively smaller things low on the horizon.To complicate things harder, if you can just lean over there to look at the moon between your legs, you may discover that the moon illusion vanishes. Now it's   becoming crazy! Convergence Micropsia is considered among the most popular theories nowadays.

Our minds, through the focus of our eyes, determine the distance from things and its observable dimensions.  If  you glance at the horizon, because your mind understands you are looking far away, our eyes focuses far out. A definite size of the moon is observed. Our mind thinks that it would be much far, though it is, therefore inevitably you infer that the moon has to be high. But nothing is there for your eyes to concentrate upon when staring up into the dark sky at night, thus eyes return to their resting concentration, and is only just few meters away. The mind now assumes that now the moon is far nearer than it actually is, and we clearly assume that moon isn't as large as you thought of it really was.

Convergence Microspia describes why and how the moon looks so small when it is above, instead of explaining why moon looks quite large low on the horizon. Not happy even now? Ah, actually, there are not many experts anyway, but the controversy about the illusion of the moon definitely will keep going.