Huhh, What....

 A little delightful visual entertainment today via Futility Closet:

https://www.futilitycloset.com/2021/12/15/keep-right/

…and another fun one by Sugihara (of many he’s done):

https://www.youtube.com/watch?v=oWfFco7K9v8

Wheel of Illusion

 Well, this is a lovely optical illusion:

https://twitter.com/SteveStuWill/status/1460013215593553920

Don't Believe Your Eyes

 A nice geometric illusion from Futility Closet:

https://www.futilitycloset.com/2021/10/07/a-geometric-illusion/

Just For Fun & Amazement (illusions)

This is old (…well around 5 years old), but Cliff Pickover retweeted one of my favorite static illusions yesterday, the “Scintillating Grid Illusion” by gamer Will Kerslake. The grid contains 12 black dots at intersections but you can’t see them all at the same time! Be befuddled:

Here’s one piece on it:

https://www.sciencealert.com/here-s-why-you-can-t-see-all-12-black-dots-in-this-crazy-optical-illusion

...shortly after preparing the above post yesterday, I then came across this Tweet introducing me to the Ames Window motion illusion, which was possibly new to me (and definitely worth checking out if you're unfamiliar with it):

https://twitter.com/gunsnrosesgirl3/status/1432793383760764938

And here is Veritasium's great take on it:

https://www.youtube.com/watch?v=dBap_Lp-0oc

Fooling the Eyes

       

For awhile now I’ve used the above wonderful static optical illusion (of non-existent black dots appearing-and disappearing at grid intersections) as a header for my Twitter account, always presuming it was an example of the “Hermann grid illusion,” but I just recently discovered it is actually a slight variation known as the “scintillating grid illusion.” You can read a tad more about it here:

https://psychology.wikia.org/wiki/Grid_illusion

https://www.newworldencyclopedia.org/entry/Grid_illusion

https://en.wikipedia.org/wiki/Grid_illusion

Whoooaaa

Here are a couple of wonderful recent optical motion illusions from @jagarikin on Twitter (there is NO motion; nothing is moving):

https://twitter.com/jagarikin/status/1228122662368448512

https://twitter.com/jagarikin/status/1233780266780389378

(....is it any wonder that eyewitness testimony is so unreliable!)

Sunday Illusion

OK, for your Sunday entertainment and perspicacious pondering I’ll pass along this optical illusion that seems to be making the rounds — it’s somewhat cool, and I didn’t recall seeing it before:

via GIPHY

It works better for some folks than for others, and there are actually multiple ways to make it work besides the “breathing” routine. Despite being passed around a lot right now, when I tried to learn more about it I found it went back to at least 2015, but still haven’t found the originator or precise explanation for how it works. In fact, for something that’s been out there for at least 4 years I’m surprised how little I could find about it on the Web. Maybe the best explanation (and still not all that incisive or neurologically revealing) is this comment placed on one site:

“The dots aren't moving. There are two sets of dots in alternating points around the circle, and they're flashing between the two sets. The illusion of movement comes from the suggestion to the viewer that the dots are moving, resulting in subconsciously following in the chosen direction.”

Anyway, if you know more about it feel free to elucidate in the comments below! ;)

Seeing Ain't Believing...

             "Somethin's happenin' here; what it is ain't exactly clear..."
                                                        -- Buffalo Springfield

At some point last week John Baez sent out this tweet and optical illusion and I found it quite remarkable:

https://twitter.com/johncarlosbaez/status/1050190866634092544

There are a great many such “motion” illusions. They are fascinating and a constant reminder of how easily manipulated human perception is.

Here’s another favorite of mine:

Some additional ones can be seen here (and there are many more):

https://www.buzzfeed.com/kellyoakes/captivating-optical-illusion-gifs-that-will-make-your-brain

Anyway, a day or two after John's post Mike Lawler (and others) tweeted out this “motion” illusion, remarking how amazing it was; some even calling it one of the strongest illusions they had ever seen! 

Yet I, and some other folks got little from this example.  The prior examples are those of motion that is mis-perceived, while this is one where motion that doesn’t even occur is perceived to take place. There are many examples of this genre of illusion, and I’ve probably seen at least 20+ I find more effective than this one — you can google “motion optical illusions” to find many; embiggen them for better effect (...FWIW, I also always had problems seeing the old “magic eye” pictures). For that matter, there are a multitude of static (motionless) optical illusions I find far more impressive than the above heralded illusion.

So I’m very curious what is going on with those of us who see little motion with this particular one? What divides the individuals who do and don’t “fall” for this illusion? Are there divisions along gender or age, left-handed vs. right-handed, Chinese-speaking vs. English, or other significant categories? Some explanations lean toward differences in depth perception... but then do those differences themselves fall along any category lines, or are they just randomly dispersed in the population?
We know from court cases, and psychology experiments for that matter, how weak eyewitness testimony can be even though people have great confidence in their visual conclusions. I wonder too, more generally, what differences may exist between people who seem to handle high-level abstraction (as in math) fairly easily, and those who have great difficulty dealing with concepts they can't "picture" in their head -- is there a difference in how these groups "see" certain optical illusions? So many questions???

I suspect the differences in responses to various illusions has been well-studied before, perhaps even some PhD. theses; it certainly seems fodder for analysis.

Meanwhile, not at all an illusion, but simply a mesmerizing visual delight, I'll close out with this deeeep zoom into the Mandelbrot Set... enjoy!:

Four Circles... Really!

An optical illusion for your entertainment and delectation!:

http://i.imgur.com/RYHtQ.jpg