Neat optical illusion

Forty-Two · 13th June 2006, 06:00 PM

This was listed on FARK.com a few days ago as "The coolest trick you'll play on your brain today." It's a great optical illusion; I hope you enjoy it as much as I have.

http://www.johnsadowski.com/big_spanish_castle.html

(Note: It works best if you follow the directions; I swear it's not one of those "crazy, scary-looking image jumps out at you" tricks.)

tkingdoll · 13th June 2006, 06:04 PM

Whoa! That totally rocks!

It only stays in colour for a split second for me, even if I don't move my eyes. Or maybe I'm moving them without realising. Either way, that's ace.

Meffy · 13th June 2006, 06:08 PM

Pretty good, reminds me of the reverse-color US flag projection trick. :-)

Here's the most jawdropping animated GIF I've ever seen.

http://vygotsky.sfasu.edu/Courses/ps...te_circles.jpg

The amazing part is that it's not animated. Let your gaze wander around the pattern and see the "snakes" slowly turn while not moving at all. I can't resist seeing motion even while knowing perfectly well that it's static. Can you?

[edit] Here's the parent page: http://vygotsky.sfasu.edu/Courses/psy133/illusions.html

tkingdoll · 13th June 2006, 06:09 PM

Originally Posted by Meffy

Pretty good, reminds me of the reverse-color US flag projection trick. :-)

Here's the most jawdropping animated GIF I've ever seen.

http://vygotsky.sfasu.edu/Courses/ps...te_circles.jpg

The amazing part is that it's not animated. Let your gaze wander around the pattern and see the "snakes" slowly turn while not moving at all. I can't resist seeing motion even while knowing perfectly well that it's static. Can you?

[edit] Here's the parent page: http://vygotsky.sfasu.edu/Courses/psy133/illusions.html

I can get one to stay still if I focus on the dots, but the ones in my peripheral vision still spin. I love this sort of thing. Richard Wiseman did a great presentation of visual illusions at TAM4, totally worth seeing.

Meffy · 13th June 2006, 06:22 PM

For me, as long as I don't look at one place for more than a couple seconds, the wheels whirl. I can't figure how it does that. I think I understand how the trick in the OP works -- overlays an after-image (in reverse color, as they are) upon a grayscale image. Very clever, so dramatic!

Did Wiseman's presentation touch on the problems with eyewitness accounts? Tricks of motion and geometry that make Venus seem to dash around like an alien recon ship, that kind thing?

Floyt · 13th June 2006, 06:36 PM

wrrglll...

alfaniner · 13th June 2006, 07:00 PM

OK, whenever this subject comes up I always like to bring out this one. Look closely and note which side has the angry face.

Then, squint (or view at a distance) and see what happens!

First found on Ian Rowland's pages.
Ian Rowland illusion page

Taffer · 13th June 2006, 10:50 PM

Originally Posted by Forty-Two

This was listed on FARK.com a few days ago as "The coolest trick you'll play on your brain today." It's a great optical illusion; I hope you enjoy it as much as I have.

http://www.johnsadowski.com/big_spanish_castle.html

(Note: It works best if you follow the directions; I swear it's not one of those "crazy, scary-looking image jumps out at you" tricks.)

Very cool!

Zep · 13th June 2006, 11:28 PM

Love this stuff! Keep it up!

PS. We should post it on the homeopath forums, and see if they get freaked by it. You know - things appearing to be what they are not, and all that...

This Guy · 13th June 2006, 11:35 PM

Cool indeed!

I love this stuff

richardm · 14th June 2006, 01:31 AM

Hmm, I saw the castle one the other day and couldn't make it work. Perhaps the server was being hammered and I wasn't allowing time for the second image to load. It certainly works now

This is a pretty nice one (also from the link above, in fact)

Tirdun · 14th June 2006, 04:41 AM

Originally Posted by richardm

Hmm, I saw the castle one the other day and couldn't make it work. Perhaps the server was being hammered and I wasn't allowing time for the second image to load. It certainly works now

This is a pretty nice one (also from the link above, in fact)

Paul C. Anagnostopoulos · 14th June 2006, 05:02 AM

Originally Posted by Teek

It only stays in colour for a split second for me, even if I don't move my eyes. Or maybe I'm moving them without realising. Either way, that's ace.

Stare at the dot longer.

Hey Ian! This one's cool!

~~ Paul

tkingdoll · 14th June 2006, 05:17 AM

Originally Posted by Paul C. Anagnostopoulos

Stare at the dot longer.

Hey Ian! This one's cool!

~~ Paul

I fear for my already fragile eyesight

Talking of which, stare at my avatar for a few moments and you'll get a nice surprise!

CFLarsen · 14th June 2006, 05:42 AM

Very cool!

But, I still think Adelson's grey checkerboard is the most amazing optical illusion.

Hey, Ian! Do you still thing the two grey squares are not the same shade of grey?

tkingdoll · 14th June 2006, 05:56 AM

Originally Posted by CFLarsen

Very cool!

But, I still think Adelson's grey checkerboard is the most amazing optical illusion.

Hey, Ian! Do you still thing the two grey squares are not the same shade of grey?

Agreed, I really like that one. A proof can be found here: http://img69.imageshack.us/img69/8523/chess5vo.jpg - the B square has been cut out and moved next to the A square.

Ladewig · 14th June 2006, 06:01 AM

Good stuff.

richardm · 14th June 2006, 06:03 AM

Originally Posted by Paul C. Anagnostopoulos

Stare at the dot longer.

Also, if you've stared adequately long at the dot and then look at a different part of the image then the colours do disappear; but looking back at the dot makes the colours fade back in. It's very strange, I love it!

malaka · 14th June 2006, 06:14 AM

Originally Posted by CFLarsen

Very cool!

But, I still think Adelson's grey checkerboard is the most amazing optical illusion.

Agreed. And followed closely by the Dragon Illusion. I have one of these atop my cube entrance at work.

bmillsap · 14th June 2006, 06:21 AM

Originally Posted by CFLarsen

But, I still think Adelson's grey checkerboard is the most amazing optical illusion.

This has always been my favorite, the one I (and everyone else I show it to) consistently just can't believe is true, but there it is.

Meffy · 14th June 2006, 07:30 AM

Originally Posted by CFLarsen

Hey, Ian! Do you still thing the two grey squares are not the same shade of grey?

Did he deny it even after being shown the truth? Did he try chopping out a bit of square A in a graphics program and dragging it over B? :-D

I find the people who most vehemently defend indefensible positions are usually those least willing to try simple experiments for themselves -- experiments that would quickly demonstrate what's going on.

Hellbound · 14th June 2006, 07:52 AM

Meffy:

IIRC, his actual argument, after getting past the "I'm right because you're all idiots!" stage, was that color is, specifically, what the brain interprets, and not what is actually there.

Thus, to him, it really is a different shade until you move it.

tkingdoll · 14th June 2006, 08:18 AM

Originally Posted by Huntsman

Meffy:

IIRC, his actual argument, after getting past the "I'm right because you're all idiots!" stage, was that color is, specifically, what the brain interprets, and not what is actually there.

Thus, to him, it really is a different shade until you move it.

Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position?

tsg · 14th June 2006, 08:20 AM

Originally Posted by tkingdoll

Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position?

[heavy sarcasm]That doesn't sound like Ian.[/heavy sarcasm]

Hellbound · 14th June 2006, 08:23 AM

Originally Posted by tkingdoll

Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position?

Not Ian! HAven't you heard? He's the only person that never lies and is always right, so you obviously must be incorrect.

Mercutio · 14th June 2006, 08:33 AM

Originally Posted by tkingdoll

Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position?

Ian's argument was consistent with his position in other threads. Huntsman pretty much got it.

From a materialist perspective, the job of science is to understand the discrepancy between what is observed, which changes, and what is physically there (which we define as "real"). From Ian's idealist perspective, the job of science is to understand the discrepancy between what is observed (which we define as "real") and what is physically measured (which may differ for stimuli which are observed to be the same). It is a perfectly good philosophical position from which to explore the same questions as science does when approached from a materialist view. The job of connecting "out there" with "in here" is the same; the axiomatic assumptions of "what is real" are different.

Bob Klase · 14th June 2006, 08:56 AM

This has been my favorite for a long time:

http://dogfeathers.com/java/spirals.html

There's a downloadable version here:

http://www.grand-illusions.com/pinwheel.htm

Binary arts used to make a metal disk that you could spin on a table with this on it. Haven't seen it for 5-6 years though so guess they stopped.

There's also some good ones here that he's gathered from other sites:

http://illusionsetc.blogspot.com/200...c_archive.html

alfaniner · 14th June 2006, 09:16 AM

Originally Posted by malaka

Agreed. And followed closely by the Dragon Illusion. I have one of these atop my cube entrance at work.

YouTube had a very popular video of that illusion on its "Most Viewed" for some time. It might still be on the site if you search for it.

malaka · 14th June 2006, 10:53 AM

Originally Posted by alfaniner

YouTube had a very popular video of that illusion on its "Most Viewed" for some time. It might still be on the site if you search for it.

A video of the illusion is also included on the site, itself. Check http://www.grand-illusions.com/image...n_illusion.wmv

Overman · 14th June 2006, 11:17 AM

So cool.

Give me more!!!

Paul C. Anagnostopoulos · 14th June 2006, 11:31 AM

Originally Posted by Mercutio

From a materialist perspective, the job of science is to understand the discrepancy between what is observed, which changes, and what is physically there (which we define as "real"). From Ian's idealist perspective, the job of science is to understand the discrepancy between what is observed (which we define as "real") and what is physically measured (which may differ for stimuli which are observed to be the same). It is a perfectly good philosophical position from which to explore the same questions as science does when approached from a materialist view. The job of connecting "out there" with "in here" is the same; the axiomatic assumptions of "what is real" are different.

I basically agree, but things get sticky when "what is observed" changes as we vary the observing apparatus (senses), because it is not clear where the boundary between the observer and the observed lies.

For example, consider the "deepest" part of my visual mechanism, the part that is fooled by the checkerboard illusion. According to Ian, that deep mechanism is part of the observed, not the observer. But would you call it part of the stimuli of the illusion? Tricky, that.

~~ Paul

Meffy · 14th June 2006, 12:16 PM

Thanks to all for the clearing-up. Ian's world certainly is... erm... interesting.

Forty-Two · 14th June 2006, 01:24 PM

That dragon illusion is awesome. I printed out the PDF and made one of my own. Thanks for the link!

Mercutio · 14th June 2006, 01:37 PM

Originally Posted by Paul C. Anagnostopoulos

I basically agree, but things get sticky when "what is observed" changes as we vary the observing apparatus (senses), because it is not clear where the boundary between the observer and the observed lies.

For example, consider the "deepest" part of my visual mechanism, the part that is fooled by the checkerboard illusion. According to Ian, that deep mechanism is part of the observed, not the observer. But would you call it part of the stimuli of the illusion? Tricky, that.

~~ Paul

Actually, I think Ian has been quite consistent on that. The explanations for that illusion (as well as the Muller grid illusion) rely in part on the structure of perceptive fields in the retina, which (through a differential center/surround positive and negative feedback mechanism, which I can explain but which is not the point here) mechanically (close enough) makes edges more salient, makes colors dependent on their surrounding colors (where "color" is defined subjectively, not by wavelength), and can be modeled mechanically quite easily (probably already is being used in mechanical vision for robotic uses, but I don't know that--it is a tremendously useful little trick). Likewise, the spectral sensitivities of the alpha, beta, and gamma photopigments can also be modeled mechanically and used to describe how differing combinations of wavelengths can be associated with the exact same experienced color.

In both cases (receptive fields and trichromatic theory), the sensory apparatus mechanisms are part of the illusion (indeed, it would not happen without it); both are part of what Ian's ideal observer must experience. Both, to Ian, are part of the outside-of-observer, seemingly physical (although I think Ian would perhaps argue that we cannot assume they are physical, since the only evidence we have for them is experiential) world. Ian's observer is not dependent on such things, but on the experience itself.

It takes a great deal of effort to understand Ian, but I find it quite worth it. (I do not guarantee that my explanation is the same as his--some may be my interpretation of his view...also I am in a bit of a hurry right now, prepping for class.)

alfaniner · 14th June 2006, 01:55 PM

Originally Posted by Forty-Two

That dragon illusion is awesome. I printed out the PDF and made one of my own. Thanks for the link!

I'm working on doing one with an actual dog photo but need to get it just right.

Dark Jaguar · 14th June 2006, 03:06 PM

Neato supremo, but the dragon one doesn't really seem to have the effect it's going for. I can tell it's concave, and I think that's the problem. Another part of it is I was first exposed to this sort of illusion when I was like... 4 or something, so I think my brain adapted rather well.

The rest work great.

luchog · 14th June 2006, 03:15 PM

Originally Posted by alfaniner

OK, whenever this subject comes up I always like to bring out this one. Look closely and note which side has the angry face.

If i look at it without squinting, they both look angry to me. But i have really bad eyesight, and my glasses tend to distort things a little.

luchog · 14th June 2006, 03:31 PM

I recall reading somewhere that some types of schizophrenics are not able to be fooled by some sorts of optical illusions. Something about the way their brain fails to filter then normally; which may be linked to the mechanism responsible for paranoia as well. I can't seen to find the study in my links.

n11/n12 · 14th June 2006, 03:32 PM

Originally Posted by Dark Jaguar

Neato supremo, but the dragon one doesn't really seem to have the effect it's going for. I can tell it's concave, and I think that's the problem. Another part of it is I was first exposed to this sort of illusion when I was like... 4 or something, so I think my brain adapted rather well.

Try keeping one eye closed as you look at it.

Dark Jaguar · 14th June 2006, 05:18 PM

Considering it's a 2D image on my moniter... how exactly would that help?

I'm merely saying that though I know the illusion is based on depth perception, in looking at it on my moniter the only depth can be provided by my brain's interpretation and not two viewpoints, so I doubt that my being able to see the actual depth perception was what threw it off. I just think it's the nature of how when something moves back and forth like that it immediatly jumps out at me as "concave", because it doesn't look right to my brain.

13th June 2006, 06:00 PM	#1
Forty-Two The Answer Join Date: Oct 2004 Location: Carpinteria, CA Posts: 912	Neat optical illusion This was listed on FARK.com a few days ago as "The coolest trick you'll play on your brain today." It's a great optical illusion; I hope you enjoy it as much as I have. http://www.johnsadowski.com/big_spanish_castle.html (Note: It works best if you follow the directions; I swear it's not one of those "crazy, scary-looking image jumps out at you" tricks.)

13th June 2006, 06:04 PM	#2
tkingdoll AKA TEEK Join Date: Jul 2005 Location: Up Myself Posts: 12,471	Whoa! That totally rocks! It only stays in colour for a split second for me, even if I don't move my eyes. Or maybe I'm moving them without realising. Either way, that's ace.
	__________________ www.stormmovie.net Official website of Tim Minchin's Storm Movie

13th June 2006, 06:09 PM	#4
tkingdoll AKA TEEK Join Date: Jul 2005 Location: Up Myself Posts: 12,471	Originally Posted by Meffy Pretty good, reminds me of the reverse-color US flag projection trick. :-) Here's the most jawdropping animated GIF I've ever seen. http://vygotsky.sfasu.edu/Courses/ps...te_circles.jpg The amazing part is that it's not animated. Let your gaze wander around the pattern and see the "snakes" slowly turn while not moving at all. I can't resist seeing motion even while knowing perfectly well that it's static. Can you? [edit] Here's the parent page: http://vygotsky.sfasu.edu/Courses/psy133/illusions.html I can get one to stay still if I focus on the dots, but the ones in my peripheral vision still spin. I love this sort of thing. Richard Wiseman did a great presentation of visual illusions at TAM4, totally worth seeing.
	__________________ www.stormmovie.net Official website of Tim Minchin's Storm Movie

13th June 2006, 06:36 PM	#6
Floyt Chordate Join Date: Apr 2003 Location: Cape Town! Not mugged yet. Looking for chameleons. Posts: 1,426	wrrglll...
	__________________ They had no god; they had no gods; they had no faith. What they appear to have had is a working metaphor. - Ursula K. Le Guin, "Always Coming Home"

13th June 2006, 07:00 PM	#7
alfaniner Penultimate Amazing Join Date: Aug 2001 Location: Sorth Dakonsin Posts: 11,387	OK, whenever this subject comes up I always like to bring out this one. Look closely and note which side has the angry face. Then, squint (or view at a distance) and see what happens! First found on Ian Rowland's pages. Ian Rowland illusion page
	__________________ Science doesn't lie.

13th June 2006, 06:08 PM	#3
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	Pretty good, reminds me of the reverse-color US flag projection trick. :-) Here's the most jawdropping animated GIF I've ever seen. http://vygotsky.sfasu.edu/Courses/ps...te_circles.jpg The amazing part is that it's not animated. Let your gaze wander around the pattern and see the "snakes" slowly turn while not moving at all. I can't resist seeing motion even while knowing perfectly well that it's static. Can you? [edit] Here's the parent page: http://vygotsky.sfasu.edu/Courses/psy133/illusions.html

13th June 2006, 06:22 PM	#5
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	For me, as long as I don't look at one place for more than a couple seconds, the wheels whirl. I can't figure how it does that. I think I understand how the trick in the OP works -- overlays an after-image (in reverse color, as they are) upon a grayscale image. Very clever, so dramatic! Did Wiseman's presentation touch on the problems with eyewitness accounts? Tricks of motion and geometry that make Venus seem to dash around like an alien recon ship, that kind thing?

13th June 2006, 10:50 PM	#8
Taffer Shén Tōu Join Date: Jul 2004 Location: 台中 Posts: 4,531	Originally Posted by Forty-Two This was listed on FARK.com a few days ago as "The coolest trick you'll play on your brain today." It's a great optical illusion; I hope you enjoy it as much as I have. http://www.johnsadowski.com/big_spanish_castle.html (Note: It works best if you follow the directions; I swear it's not one of those "crazy, scary-looking image jumps out at you" tricks.) Very cool!
	__________________ Die Dulce Fruere "Whereof one cannot speak, Thereof one must be silent." BUILDS YOUR ROOFS OF DEAD WOOD. BUILDS YOUR WALLS OF DEAD STONE. BUILDS YOUR DREAMS OF DEAD THOUGHTS. COMES CRYING LAUGHING SINGING BACK TO LIFE, TAKES WHAT YOU STEAL, AND PULLS THE SKINS FROM YOUR DEAD BONES SHRIEKING. -- Clay tablet in an abandoned Trickster temple.

13th June 2006, 11:28 PM	#9
Zep Banned Join Date: Sep 2002 Posts: 26,985	Love this stuff! Keep it up! PS. We should post it on the homeopath forums, and see if they get freaked by it. You know - things appearing to be what they are not, and all that...
Zep Banned Join Date: Sep 2002 Posts: 26,985

13th June 2006, 11:35 PM	#10
This Guy Master Poster Join Date: Mar 2006 Location: On the corner of WALK and DON'T WALK Posts: 2,000	Cool indeed! I love this stuff
	__________________ I'm lost. I've gone to find me. If I should return before I get back, please ask me to wait!

14th June 2006, 01:31 AM	#11
richardm Philosopher Join Date: Aug 2001 Posts: 9,270	Hmm, I saw the castle one the other day and couldn't make it work. Perhaps the server was being hammered and I wasn't allowing time for the second image to load. It certainly works now This is a pretty nice one (also from the link above, in fact)
richardm Philosopher Join Date: Aug 2001 Posts: 9,270	__________________ Rimmer: Look at her! Magnificent woman! Very prim, very proper, almost austere. Some people took her for cold, thought she was aloof. Not a bit of it. She just despised fools. Quite tragic, really, because otherwise I think we'd have got on famously.

14th June 2006, 04:41 AM	#12
Tirdun Muse Join Date: Feb 2006 Location: Near DC, in an underground NWO bunker Posts: 637	Originally Posted by richardm Hmm, I saw the castle one the other day and couldn't make it work. Perhaps the server was being hammered and I wasn't allowing time for the second image to load. It certainly works now This is a pretty nice one (also from the link above, in fact)
	__________________ The rain has a such a lovely sound to those who're six feet underground The leaves will bury every year and no one knows I'm gone -Tom Waits May You Never Thirst, Slàinte!

14th June 2006, 05:02 AM	#13
Paul C. Anagnostopoulos Nap, interrupted. Join Date: Aug 2001 Location: a little toolshed Posts: 18,592	Originally Posted by Teek It only stays in colour for a split second for me, even if I don't move my eyes. Or maybe I'm moving them without realising. Either way, that's ace. Stare at the dot longer. Hey Ian! This one's cool! ~~ Paul
	__________________ Millions long for immortality who do not know what to do with themselves on a rainy Sunday afternoon. ---Susan Ertz RIP Mr. Skinny

14th June 2006, 05:17 AM	#14
tkingdoll AKA TEEK Join Date: Jul 2005 Location: Up Myself Posts: 12,471	Originally Posted by Paul C. Anagnostopoulos Stare at the dot longer. Hey Ian! This one's cool! ~~ Paul I fear for my already fragile eyesight Talking of which, stare at my avatar for a few moments and you'll get a nice surprise!
	__________________ www.stormmovie.net Official website of Tim Minchin's Storm Movie

14th June 2006, 05:42 AM	#15
CFLarsen Penultimate Amazing Join Date: Aug 2001 Posts: 42,804	Very cool! But, I still think Adelson's grey checkerboard is the most amazing optical illusion. Hey, Ian! Do you still thing the two grey squares are not the same shade of grey?
	__________________ SkepticReport.com

14th June 2006, 05:56 AM	#16
tkingdoll AKA TEEK Join Date: Jul 2005 Location: Up Myself Posts: 12,471	Originally Posted by CFLarsen Very cool! But, I still think Adelson's grey checkerboard is the most amazing optical illusion. Hey, Ian! Do you still thing the two grey squares are not the same shade of grey? Agreed, I really like that one. A proof can be found here: http://img69.imageshack.us/img69/8523/chess5vo.jpg - the B square has been cut out and moved next to the A square.
	__________________ www.stormmovie.net Official website of Tim Minchin's Storm Movie

14th June 2006, 06:01 AM	#17
Ladewig Hipster alien Join Date: Dec 2001 Location: not measurable Posts: 16,807	Good stuff.

14th June 2006, 06:03 AM	#18
richardm Philosopher Join Date: Aug 2001 Posts: 9,270	Originally Posted by Paul C. Anagnostopoulos Stare at the dot longer. Also, if you've stared adequately long at the dot and then look at a different part of the image then the colours do disappear; but looking back at the dot makes the colours fade back in. It's very strange, I love it!
richardm Philosopher Join Date: Aug 2001 Posts: 9,270	__________________ Rimmer: Look at her! Magnificent woman! Very prim, very proper, almost austere. Some people took her for cold, thought she was aloof. Not a bit of it. She just despised fools. Quite tragic, really, because otherwise I think we'd have got on famously.

14th June 2006, 06:14 AM	#19
malaka Graduate Poster Join Date: May 2002 Location: columbus Posts: 1,164	Originally Posted by CFLarsen Very cool! But, I still think Adelson's grey checkerboard is the most amazing optical illusion. Agreed. And followed closely by the Dragon Illusion. I have one of these atop my cube entrance at work.

14th June 2006, 06:21 AM	#20
bmillsap Scholar Join Date: Nov 2004 Posts: 79	Originally Posted by CFLarsen But, I still think Adelson's grey checkerboard is the most amazing optical illusion. This has always been my favorite, the one I (and everyone else I show it to) consistently just can't believe is true, but there it is.
bmillsap Scholar Join Date: Nov 2004 Posts: 79

14th June 2006, 07:30 AM	#21
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	Originally Posted by CFLarsen Hey, Ian! Do you still thing the two grey squares are not the same shade of grey? Did he deny it even after being shown the truth? Did he try chopping out a bit of square A in a graphics program and dragging it over B? :-D I find the people who most vehemently defend indefensible positions are usually those least willing to try simple experiments for themselves -- experiments that would quickly demonstrate what's going on.

14th June 2006, 07:52 AM	#22
Hellbound Abiogenic Spongiform Join Date: Sep 2002 Location: In a handbasket Posts: 8,924	Meffy: IIRC, his actual argument, after getting past the "I'm right because you're all idiots!" stage, was that color is, specifically, what the brain interprets, and not what is actually there. Thus, to him, it really is a different shade until you move it.

14th June 2006, 08:18 AM	#23
tkingdoll AKA TEEK Join Date: Jul 2005 Location: Up Myself Posts: 12,471	Originally Posted by Huntsman Meffy: IIRC, his actual argument, after getting past the "I'm right because you're all idiots!" stage, was that color is, specifically, what the brain interprets, and not what is actually there. Thus, to him, it really is a different shade until you move it. Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position?
	__________________ www.stormmovie.net Official website of Tim Minchin's Storm Movie

14th June 2006, 08:20 AM	#24
tsg Philosopher Join Date: Sep 2005 Location: Location: Location: Posts: 6,771	Originally Posted by tkingdoll Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position? [heavy sarcasm]That doesn't sound like Ian.[/heavy sarcasm]
	__________________ Being offended by someone questioning your beliefs is a sign that you should be questioning them. In the beginning there was nothing. And the Lord said "Let There Be Light!" And still there was nothing, but at least now you could see it.

14th June 2006, 08:23 AM	#25
Hellbound Abiogenic Spongiform Join Date: Sep 2002 Location: In a handbasket Posts: 8,924	Originally Posted by tkingdoll Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position? Not Ian! HAven't you heard? He's the only person that never lies and is always right, so you obviously must be incorrect.

14th June 2006, 08:33 AM	#26
Mercutio Shakespeare's Sock Puppet Join Date: Mar 2003 Location: Live Free Or Die Posts: 16,325	Originally Posted by tkingdoll Or, he couldn't believe it was different, tried it in Photoshop, realised he was wrong, but had gone too far to back down so invented a ridiculous argument to try and support his ailing position? Ian's argument was consistent with his position in other threads. Huntsman pretty much got it. From a materialist perspective, the job of science is to understand the discrepancy between what is observed, which changes, and what is physically there (which we define as "real"). From Ian's idealist perspective, the job of science is to understand the discrepancy between what is observed (which we define as "real") and what is physically measured (which may differ for stimuli which are observed to be the same). It is a perfectly good philosophical position from which to explore the same questions as science does when approached from a materialist view. The job of connecting "out there" with "in here" is the same; the axiomatic assumptions of "what is real" are different.
	__________________ "But to see her was to love her Love but her, and love forever."

14th June 2006, 08:56 AM	#27
Bob Klase Master Poster Join Date: Mar 2002 Location: Largo, FL Posts: 2,833	This has been my favorite for a long time: http://dogfeathers.com/java/spirals.html There's a downloadable version here: http://www.grand-illusions.com/pinwheel.htm Binary arts used to make a metal disk that you could spin on a table with this on it. Haven't seen it for 5-6 years though so guess they stopped. There's also some good ones here that he's gathered from other sites: http://illusionsetc.blogspot.com/200...c_archive.html

14th June 2006, 09:16 AM	#28
alfaniner Penultimate Amazing Join Date: Aug 2001 Location: Sorth Dakonsin Posts: 11,387	Originally Posted by malaka Agreed. And followed closely by the Dragon Illusion. I have one of these atop my cube entrance at work. YouTube had a very popular video of that illusion on its "Most Viewed" for some time. It might still be on the site if you search for it.
	__________________ Science doesn't lie.

14th June 2006, 10:53 AM	#29
malaka Graduate Poster Join Date: May 2002 Location: columbus Posts: 1,164	Originally Posted by alfaniner YouTube had a very popular video of that illusion on its "Most Viewed" for some time. It might still be on the site if you search for it. A video of the illusion is also included on the site, itself. Check http://www.grand-illusions.com/image...n_illusion.wmv

14th June 2006, 11:17 AM	#30
Overman Master Poster Join Date: Feb 2006 Location: Chicagoland Posts: 2,630	So cool. Give me more!!!
	__________________ Our new album 'The Future is Gonna be Great' on iTunes!!! Our old 'The Evolution EP' still on iTunes

14th June 2006, 11:31 AM	#31
Paul C. Anagnostopoulos Nap, interrupted. Join Date: Aug 2001 Location: a little toolshed Posts: 18,592	Originally Posted by Mercutio From a materialist perspective, the job of science is to understand the discrepancy between what is observed, which changes, and what is physically there (which we define as "real"). From Ian's idealist perspective, the job of science is to understand the discrepancy between what is observed (which we define as "real") and what is physically measured (which may differ for stimuli which are observed to be the same). It is a perfectly good philosophical position from which to explore the same questions as science does when approached from a materialist view. The job of connecting "out there" with "in here" is the same; the axiomatic assumptions of "what is real" are different. I basically agree, but things get sticky when "what is observed" changes as we vary the observing apparatus (senses), because it is not clear where the boundary between the observer and the observed lies. For example, consider the "deepest" part of my visual mechanism, the part that is fooled by the checkerboard illusion. According to Ian, that deep mechanism is part of the observed, not the observer. But would you call it part of the stimuli of the illusion? Tricky, that. ~~ Paul
	__________________ Millions long for immortality who do not know what to do with themselves on a rainy Sunday afternoon. ---Susan Ertz RIP Mr. Skinny

14th June 2006, 12:16 PM	#32
Meffy Anthropomorphic Skunk Join Date: Feb 2004 Location: Unincorporated Territory of Croatan Posts: 4,232	Thanks to all for the clearing-up. Ian's world certainly is... erm... interesting.

14th June 2006, 01:24 PM	#33
Forty-Two The Answer Join Date: Oct 2004 Location: Carpinteria, CA Posts: 912	That dragon illusion is awesome. I printed out the PDF and made one of my own. Thanks for the link!

14th June 2006, 01:37 PM	#34
Mercutio Shakespeare's Sock Puppet Join Date: Mar 2003 Location: Live Free Or Die Posts: 16,325	Originally Posted by Paul C. Anagnostopoulos I basically agree, but things get sticky when "what is observed" changes as we vary the observing apparatus (senses), because it is not clear where the boundary between the observer and the observed lies. For example, consider the "deepest" part of my visual mechanism, the part that is fooled by the checkerboard illusion. According to Ian, that deep mechanism is part of the observed, not the observer. But would you call it part of the stimuli of the illusion? Tricky, that. ~~ Paul Actually, I think Ian has been quite consistent on that. The explanations for that illusion (as well as the Muller grid illusion) rely in part on the structure of perceptive fields in the retina, which (through a differential center/surround positive and negative feedback mechanism, which I can explain but which is not the point here) mechanically (close enough) makes edges more salient, makes colors dependent on their surrounding colors (where "color" is defined subjectively, not by wavelength), and can be modeled mechanically quite easily (probably already is being used in mechanical vision for robotic uses, but I don't know that--it is a tremendously useful little trick). Likewise, the spectral sensitivities of the alpha, beta, and gamma photopigments can also be modeled mechanically and used to describe how differing combinations of wavelengths can be associated with the exact same experienced color. In both cases (receptive fields and trichromatic theory), the sensory apparatus mechanisms are part of the illusion (indeed, it would not happen without it); both are part of what Ian's ideal observer must experience. Both, to Ian, are part of the outside-of-observer, seemingly physical (although I think Ian would perhaps argue that we cannot assume they are physical, since the only evidence we have for them is experiential) world. Ian's observer is not dependent on such things, but on the experience itself. It takes a great deal of effort to understand Ian, but I find it quite worth it. (I do not guarantee that my explanation is the same as his--some may be my interpretation of his view...also I am in a bit of a hurry right now, prepping for class.)
	__________________ "But to see her was to love her Love but her, and love forever."

14th June 2006, 01:55 PM	#35
alfaniner Penultimate Amazing Join Date: Aug 2001 Location: Sorth Dakonsin Posts: 11,387	Originally Posted by Forty-Two That dragon illusion is awesome. I printed out the PDF and made one of my own. Thanks for the link! I'm working on doing one with an actual dog photo but need to get it just right.
	__________________ Science doesn't lie.