# What the heck am I seeing here? \[optical illusion\] **URL:** \ **Category:** Factual Questions\ **Created:** [June 29, 2013, 4:28pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210 "2013-06-29T16:28:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![randwill](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@randwill](https://boards.straightdope.com/u/randwill)\ **Post date:** [June 29, 2013, 4:28pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/1 "2013-06-29T16:28:51Z")
“25 of the most mind-blowing optical illusions ever posted on the Web” [http://now.msn.com/funny-optical-illusions](http://now.msn.com/funny-optical-illusions) All of these photos are fun to study and I can figure out what is weird and why it looks weird for all of them except one. What are we seeing in the second (of 25) picture which looks like a globe of grass? ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [June 29, 2013, 4:36pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/2 "2013-06-29T16:36:57Z")
It looks like a sidewalk chalk drawing. Some of them do amazing things with perspective. ---
**Author:** ![TreacherousCretin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/treacherouscretin/32/476_2.png) [@TreacherousCretin](https://boards.straightdope.com/u/TreacherousCretin)\ **Post date:** [June 29, 2013, 4:40pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/3 "2013-06-29T16:40:57Z")
A _very_ good sidewalk chalk drawing. From directly overhead, the “green globe” would be seen as a long green ellipse. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [June 29, 2013, 4:42pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/4 "2013-06-29T16:42:46Z")
Oh no, another [grid ball](http://boards.straightdope.com/sdmb/showthread.php?t=678744)! ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 29, 2013, 4:44pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/5 "2013-06-29T16:44:42Z")
I’m pretty sure that’s just man standing next to a faded oil spot. ETA: Sorry I looked and posted without reading the last sentence of the OP. I thought you were talking about the first picture. Yeah, that’s a chalk drawing. A very large chalk drawing. Well, maybe not that large now that I look at it some more. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [June 29, 2013, 4:45pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/6 "2013-06-29T16:45:39Z")
No, it’s actual dirt and grass. It’s just not the shape you think it is. [How A Parisian Artist Created This Stunning Optical Illusion](http://gizmodo.com/5818835/how-a-parisian-artist-created-this-stunning-optical-illusion) ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 29, 2013, 4:50pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/7 "2013-06-29T16:50:59Z")
Aha! See [here](http://www.pariscotejardin.fr/2011/06/l-anamorphose-du-jardin-ephemere-du-parvis-de-lhotel-de-ville-de-paris/). It’s a kind of park feature. ---
**Author:** ![randwill](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@randwill](https://boards.straightdope.com/u/randwill)\ **Post date:** [June 29, 2013, 4:57pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/8 "2013-06-29T16:57:50Z")
> [@WhyNot](#): > > No, it’s actual dirt and grass. It’s just not the shape you think it is. [http://gizmodo.com/5818835/how-a-parisian-artist-created-this-stunning-optical-illusion](http://gizmodo.com/5818835/how-a-parisian-artist-created-this-stunning-optical-illusion) Thanks for the video. It’s even more amazing when you see that it is not flat or even a mound, but an irregularly landscaped surface. ---
**Author:** ![randwill](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@randwill](https://boards.straightdope.com/u/randwill)\ **Post date:** [June 29, 2013, 5:16pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/9 "2013-06-29T17:16:04Z")
Okay, while we’re at it, I can figure out all but one of these: [http://now.msn.com/double-take-photo-gallery-makes-you-look-again](http://now.msn.com/double-take-photo-gallery-makes-you-look-again) The caption says that number 12 is _not_ a lake. So what is it? Very smooth dirt? Asphalt? Salt flats? ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 29, 2013, 5:21pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/10 "2013-06-29T17:21:16Z")
> [@randwill](#): > > The caption says that number 12 is _not_ a lake. So what is it? Very smooth dirt? Asphalt? Salt flats? It’s a wall. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [June 29, 2013, 5:22pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/11 "2013-06-29T17:22:48Z")
> [@randwill](#): > > Okay, while we’re at it, I can figure out all but one of these: > > [http://now.msn.com/double-take-photo-gallery-makes-you-look-again](http://now.msn.com/double-take-photo-gallery-makes-you-look-again) > > The caption says that number 12 is _not_ a lake. So what is it? Very smooth dirt? Asphalt? Salt flats? It’s a short wall. Flip it in your brain to vertical, not horizontal. The “flare” of the sun reflecting off the water is a bunch of yellowish dry grasses. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 29, 2013, 5:25pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/12 "2013-06-29T17:25:24Z")
Title edited to clarify subject. Colibri General Questions Moderator ---
**Author:** ![randwill](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@randwill](https://boards.straightdope.com/u/randwill)\ **Post date:** [June 29, 2013, 5:29pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/13 "2013-06-29T17:29:37Z")
> [@WhyNot](#): > > It’s a short wall. Flip it in your brain to vertical, not horizontal. The “flare” of the sun reflecting off the water is a bunch of yellowish dry grasses. I don’t use the young people’s internet jargon very often, but when I finally “saw” this, I was LOL. Thanks! ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [June 29, 2013, 5:50pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/14 "2013-06-29T17:50:31Z")
Still the most amazing visual illusion I’ve ever seen: the [chessboard](http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html). Even when you know the trick, it still works. The most amazing audio illusion I’ve ever seen is the [McGurk effect](http://www.youtube.com/watch?v=G-lN8vWm3m0). Again, even when you know what’s happening, you still see the illusion. ---
**Author:** ![Rachellelogram](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rachellelogram/32/8689_2.png) [@Rachellelogram](https://boards.straightdope.com/u/Rachellelogram)\ **Post date:** [June 29, 2013, 9:47pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/15 "2013-06-29T21:47:17Z")
> [@Little\_Nemo](#): > > The most amazing audio illusion I’ve ever seen is the [McGurk effect](http://www.youtube.com/watch?v=G-lN8vWm3m0). Again, even when you know what’s happening, you still see the illusion. This is the first time I’ve encountered this “illusion.” I put that in quotes because it doesn’t seem to work on me. I hear bah regardless of what his mouth appears to be doing. But I’m also a highly verbal person, and my visual/spatial intelligence is pretty poor. Nothing wrong with my eyesight, but I’m not a visual learner. I rely on my ears far more than my eyes… wonder if that makes a difference. ---
**Author:** ![Bumbershoot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bumbershoot/32/3428_2.png) [@Bumbershoot](https://boards.straightdope.com/u/Bumbershoot)\ **Post date:** [June 29, 2013, 10:07pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/16 "2013-06-29T22:07:01Z")
> [@randwill](#): > > Okay, while we’re at it, I can figure out all but one of these: > > [http://now.msn.com/double-take-photo-gallery-makes-you-look-again](http://now.msn.com/double-take-photo-gallery-makes-you-look-again) > > The caption says that number 12 is _not_ a lake. So what is it? Very smooth dirt? Asphalt? Salt flats? #20 (the rabbit) reminded me of [this James Thurber cartoon](http://www.koikadit.net/JThurber/gull.html). ---
**Author:** ![runningdude](https://avatars.discourse-cdn.com/v4/letter/r/e9c0ed/32.png) [@runningdude](https://boards.straightdope.com/u/runningdude)\ **Post date:** [June 29, 2013, 10:58pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/17 "2013-06-29T22:58:24Z")
> [@randwill](#): > > “25 of the most mind-blowing optical illusions ever posted on the Web” > > [http://now.msn.com/funny-optical-illusions](http://now.msn.com/funny-optical-illusions) > > All of these photos are fun to study and I can figure out what is weird and why it looks weird for all of them except one. What are we seeing in the second (of 25) picture which looks like a globe of grass? I’ve seen a photo of this from a different angle. It is a lawn with oblong curbs going through it. From any any other angle, it looks quite distorted. I think it is in Paris, IIRC. ---
**Author:** ![fachverwirrt](https://avatars.discourse-cdn.com/v4/letter/f/94ad74/32.png) [@fachverwirrt](https://boards.straightdope.com/u/fachverwirrt)\ **Post date:** [June 29, 2013, 10:59pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/18 "2013-06-29T22:59:56Z")
> [@randwill](#): > > Okay, while we’re at it, I can figure out all but one of these: > > [http://now.msn.com/double-take-photo-gallery-makes-you-look-again](http://now.msn.com/double-take-photo-gallery-makes-you-look-again) > > The caption says that number 12 is _not_ a lake. So what is it? Very smooth dirt? Asphalt? Salt flats? What I like about that one is that the mouseover text for #14 says “woman appears to have biceps”. I wasn’t aware that that was an unusual condition. ---
**Author:** ![TreacherousCretin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/treacherouscretin/32/476_2.png) [@TreacherousCretin](https://boards.straightdope.com/u/TreacherousCretin)\ **Post date:** [June 29, 2013, 11:33pm UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/19 "2013-06-29T23:33:55Z")
> [@WhyNot](#): > > No, it’s actual dirt and grass. It’s just not the shape you think it is. [http://gizmodo.com/5818835/how-a-parisian-artist-created-this-stunning-optical-illusion](http://gizmodo.com/5818835/how-a-parisian-artist-created-this-stunning-optical-illusion) Better yet. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [June 30, 2013, 4:49am UTC](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210/20 "2013-06-30T04:49:47Z")
This effect is called [(perspectival) anamorphosis](http://en.wikipedia.org/wiki/Anamorphosis), most famously seen in Holbein the Younger’s [_The Ambassadors_](http://en.wikipedia.org/wiki/The_Ambassadors_%28Holbein%29) and earliest in da Vinci’s, [_Leonardo’s Eye_](https://www.google.com/search?q=Leonardo%27s%20Eye&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=MbjPUe-vHJfI4APru4HoAQ&biw=1024&bih=604&sei=NrjPUfeaEtHh4AOymYCwCA#facrc=0%3Bleonardo%27s%20eye%20anamorphosis&imgrc=_). CMC fnord! [Next page](https://boards.straightdope.com/t/what-the-heck-am-i-seeing-here-optical-illusion/662210.md?page=2)