Take a look at the image below.
Do you see the horizontal lines angled toward
each other? If so, you’re not alone. The
reality is that the vertical lines are completely parallel. Don’t
believe me? Then try this link where you
can hide the shorter lines and see for yourself. Then play around with the shorter lines to
adjust the angel and watch as the horizontal line seem to become more or less
tilted toward each other.
What Do You See?
The Zöllner illusion is a commonly demonstrated optical
illusion. Created in 1860 by an astrophysicist, Johann Karl Friedrich Zöllner,
this illusion presents a series of seemingly tilted long lines crossed with
overlapping shorter lines. The seemingly tilted long lines appear as if they
would intersect one another if they were extended. However, the lines are actually parallel to
each other.\
How Does It Work?
This optical illusion shows how an image’s background can
distort the perceived appearance of straight lines. Several explanations for the
Zöllner illusion have been offered. First, the angle of the short lines
compared to the long lines creates the perception of depth. One of the lines
appears to be closer to us and the other farther away. Another possible
explanation is that our brain tries to increase the angles between the long and
short lines. The result is a distortion resulting from our brain attempting to
bend the lines away and towards each other.
Most optical illusions result from the way that the images are
captured with the eyes and are reconstructed by the visual cortex. While we may believe that the information we
receive from our senses is accurate, this information doesn’t actually
correspond exactly to reality. With
vision, for example, the image that hits the retina contains considerably more
information than what the optic nerve conveys to the brain. The brain compensates for this enormous loss
of information to provide us with visual perceptions that possess contrast,
color, and movement. In order to do
this, the brain uses abstract boundaries that clarify, fill in or elaborate the
small segments of reality that are actually provided. The brain's tendency to
interpret visual information in this way sometimes results in impression of
coherence being created where none exist.
This is the case with an optical illusion. The brain uses well-rehearsed strategies to
fill in the blanks that are supplied by the image and the incomplete segments
of the image that are supplied. For
example, if the brain interprets an image as representing distance it will use
perspective related strategies to interpret the different segments. Parallel lines going away from us into the
distance (think railroad tracks) appear to converge as if they will eventually
intersect somewhere out of our line of sight. Of course, while we may perceive railroad
tracks as seemingly converging, we logically know they are not doing so and
therefore, ignore what our eyes are communicating to our brain and dismiss the
image as an optical illusion.
Yet
when we happen upon novel images that use specific features, in this case an
image of straight lines crossed by smaller, angled lines our brain automatically
corrects for the parts that aren't communicated based on it’s interpretation of distance. However, in this case we do not have any context
as we would with railroad tracks. We don’t
look at it (unless you are already familiar with the illusion) and say, “Oh,
yeah, that’s the Zollner Illusion that makes a bunch of parallel lines look
like they’re converging. Of course, I
know better.” So we become convinced our
visual perception is accurate and have a lot of trouble when someone tells us
that our perception is faulty, trying to change the way we see it, to no
avail. As with everything in life, the
context is all important.
An interesting effect occurs if the color of the lines and
background are changed. If you make the
color of the lines green and make the color of the background red, the effect
entirely disappears and the lines will appear to be parallel as they actually
are, as long as the two colors are equally bright.
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AND BACK TO A WITH ANOTHER ANNOUNCEMENTI HEREBY ANNOUNCE THAT I AM FINISHED WITH THE 2017 A TO Z BLOGPOST CHALLENGE!
I'd like to thank all of you out there who came along with me on this journey. At times it seemed like the longest month ever while at other times I had no idea where the days had gone and how I'd keep up the pace. But I'm glad I did it and it managed to call up some new ideas and even generate a few new full length articles. You never know what the next year will bring but as of now I'll say I look forward to repeating this challenge the next time April rolls around! I'll keep you posted. You do the same. Don't stop stoppin in though, now that the excitement is over. Hopefully, I'll keep posting things you find interesting, though not at the same pace as this month.
Ciou - SYOTB