1st Prize: Koukichi Sugihara's Impossible motion: magnet-like slopes (Meiji Institute for Advanced Study of Mathematical Sciences, Japan).
2nd Prize: Counter‐intuitive illusory contours, by Bart Anderson (University of Sydney, Australia).
Here are a couple of interesting little projects devised by mathematicians — and when I say “little”, there’s one project that illustrates a man’s life’s work. Anyway, these are two entries in a Scientific American magazine competition called “Illusion Of The Year”. Here are the winners, I found the first two quite intriguing; especially the second one, because nobody knows why it happens. You’ll have to use my link to go and play the videos to find out what they’re about. You can find out more about Koukichi Sugihara’s work at his website.
A Bad Guide 
I still can’t figure out how the “impossible motion” illusion works. The accompanying text contains a sentence that might have come out of the mouth of a politician. It seems to be explaining something, but is in fact only a restatement of what you already knew:
I take this to be saying that what is “actually happening” is that you are seeing an illusion.
The second illusion is graced by another useless string of sentences:
What missing information ? The fact that “”explanation”” is put in scare quotes is simply an admission that this explanation of “explanation” explains nothing.
By the way, what is the justification for calling the things illusory that I see in those clips ? After all, I see what I see, right ? In the first example, I think I am seeing something that, when regarded from a different angle, looks incompatible with what I first though I saw. But in the second example there is no different viewpoint to make me doubt what I first saw. I see an imaginary curve going through the four points, and the curve expands and contracts. I don’t have the impression that the line is really there. I see it, but I don’t, because I know it’s imaginary. What’s illusory about that ?
I don’t have the impression that the line is really there.
Well none of it is REALLY there, Grumb. It’s all just an illusion on your screen, the whole damn thing: empty, MMcM, Languagehat — even m-l — they’re just twinkling lights.
I know it’s imaginary. What’s illusory about that ?
You only believe it’s imaginary because everyone told you it is. And it has to be an illusion, it won second place in an illusion competition. Unless you’re saying it’s only pretending to be an illusion.
You’re right that the blurb is kind of lame. You don’t need great blurb-writing skills for this. If one picture is worth a thousand words imagine what you could get for a video.
I did not understand at first that there were videos you had to watch. I found the second one quite hypnotic but tiring to look at. For the first one, I guess that the eye perceives those four “branches” as being at right angles though seen in perspective, but actually the angles are different, hence the illusion.
In New Brunswick (in Eastern Canada) there is a place called “Magnetic Hill”: it is just a section of an ordinary country road up/down a slope, where for some reason the down slope looks like an up slope, so you can let you car roll down in neutral and it seems that you are going up the slope. It is touted as a tourist attraction (without the usual associated claptrap, thankfully). I must say it was not very convincing when I tried it (the slope is not very steep).
The whole problem with this and your place in New Brunswick is that once you’ve been told something exciting is going to happen you start looking for reasons why it won’t. I’d be surprised if it weren’t an instinctive human reaction. Maybe that’s what Grumbly is telling us.
Grumbly, can you give an example of something that you would call an illusion?
once you’ve been told something exciting is going to happen you start looking for reasons why it won’t.
Why put it all in the future? You can genuinely be looking forward to something exciting, and then be disappointed when it didn’t happen, without expecting disappointment beforehand.
I thought the second one was really cool. It seems to have a lot to do w/ the precise rates at which the two grey circles move. The most _useful_ illusion, though, is the face that’s enhanced by being upside down — this has obvious facebook / online dating applications.
It seems to have a lot to do w/ the precise rates at which the two grey circles move.
My wife says it looks best when you speed it up. I’m not sure how she managed to do it.
the face that’s enhanced by being upside down — this has obvious facebook / online dating applications.
If only as a warning never to go on a date with someone you’ve hitherto only seen upside down.
But I don’t like upside down. I could never get on with those Georg Baselitz images where he paints people upside down. I feel compelled to try & turn them around and it bothers me to have such a trivial impulse while I’m looking at an art work.
You can genuinely be looking forward to something exciting, and then be disappointed when it didn’t happen, without expecting disappointment beforehand.
Of course. I didn’t mean it in an Eeyore sort of way. I phrased it badly, I’m thinking about the intellectual challenge of being fooled. The enjoyment of watching a magician’s performance lies in figuring out how you’re being tricked. You don’t watch the young lady being sawn in half and then dial the police.
“Magnetic Hill”: sounds like
http://en.wikipedia.org/wiki/Electric_Brae
Yes, it must be the same phenomenon.
Grumbly, can you give an example of something that you would call an illusion?
Depends on what you think an illusion is. As I indicated above, “illusion” is usually a name given to one experience that does not seem to accord with another experience in terms of the experiences that (can be imagined to) lead from one to the other. The passage of time is crucial. It does not make sense to speak of a “static illusion”. No comparison, no illusion.
Also, it is more or less up to you whether either of two experiences is worth being characterized as “an illusion”. It depends on their being presented or imagined in a particular way, as involving a transition or sequence of time-located experiences. Consider a camera set up in a fixed position in the desert. Suppose you are shown a picture from a hot day that shows a shimmering figure in the middle distance. Then you are shown a picture from the following day that was not so hot, in which no shimmering figure is visible. It would be perfectly reasonable to comment as follows on these pictures: “On the first day, there is a person in the distance seen through heat waves. On the next day, the person is not there”. There is no reason to postulate a “fata morgana”, because there is nothing to explain away.
The presentation in terms of “pictures on two different days” is not such as to suggest or impose a sense of the two pictures being incompatible with each other. It’s different when you’re shown not two transition-less pictures, but a film made by a person driving in pick-up truck towards the shimmering figure.
Here’s another example of how important presentation and expectation are in creating the illusion of seing incompatible realities (as Crown suggested above). Consider the section of the video of “impossible motion” that follows the initial part where the balls apparently roll up-hill. The balls are resting at the summit. As the camera rotates around the set-up, you experience a change in perspective so that the summit becomes a trough in which the balls are resting. Nothing new about that: we know it from Escher drawings and trompe-l’oeil paintings. When now the balls are shown rolling up-hill, the mint-julep-sipping viewer thinks “isn’t that cute”, while the innocent rube concludes that God exists after all.
You can choose to call something “an illusion” and puzzle over it in your garage laboratory. Or you can choose to call it a “visual effect” and make zillions of box-office dollars deploying it in blockbuster films. That’s why I say that illusions are illusory. They are only illusions until someone figures out a way to see them in a different way. Movie films are no longer regarded as illusions, but rather as entertainment. Meta-entertainment, even: the “impossible motion” clip is a “making-of” clip.
It’s somehow significant that the word “illusion” is usually applied primarily to optical experiences, not tactile, olfactory etc. ones. I think this is mainly due to image technology being more developed than smell technology – facile even, and rather ho-hum. If you briefly think you hear a sound that turns out not to have an assignable source, i.e. you can’t find a source, you say that you must have been imagining the sound. There are “imaginary pains” experienced by amputees, but these can’t currently be offered as relivable experiences.
Relivable experiences for which an entrance fee can be charged.
Thank you very much Grumbly for taking the trouble to explain. That makes a lot more sense to me now and it’s something I’ve never considered. I’d assumed that an illusion had to be visual. I’ll just check a dictionary … nope: “a false idea or belief”, “deceptive appearance”, “something likely to be wrongly perceived by the senses”, so you can have an auditory illusion.
The best-known use of the word in the visual arts is in the book that keeps coming up here, old Ernst Gombrich’s Art & Illusion. We might have a competition: “Allusion Of The Year”.
so you can have an auditory illusion
Of course. But to use “illusion” in connection with hearing is, I think, to attach a scientific-sounding adjective to what most of us would usually describe as “something you’re just imagining”.
“Illusion” sounds more objective than “imagining things”, i.e. it sounds more like something that can be the object of scientific study. It is precisely this objectification of illusion that I consider misleading, because it doesn’t take time into account – the passage of time that is necessary to obtain two or more experiences that can be compared with each other. Illusions are dynamic experiences, not static phenomena. They are inherently subject to (re)interpretation over time, because they are based on appearances over time.
Does Gombrich have anything to say about that ? Remember I don’t know what Art is.
By the way, I recently discovered that Descartes, your old buddy, considered in 1641 (publication of the Meditationes de prima philosophia whether people in the street might not actually be robots. The context is his riff on the perception of wax (ceram):
(Nisi iam forte respexissem ex fenestra homines in platea transeuntes, quos etiam ipsos non minus usitate quam ceram dico me videre. Quid autem video praeter pileos et vestes, sub quibus latere possunt automata …)
Didn’t Descartes think that animals were robots ? That might be because they don’t wear deceptive clothing. Sartor Resartus is a funny piece on the topic of humans as dressed-up animals.
Except that it was the clothes that interested Carlyle, not the animals.
Well Gombrich has a lot to say about the perception of things seen over time, but he’s thinking of historical time. I wouldn’t be surprised if he talks about movement as well, though. But what you’re describing is what analytical cubism is about: that we can see and perceive things from different angles over a short period of time and then reassemble them in our mind’s eye, that seeing itself is a dynamic experience. That came out of Cezanne’s way of drawing landscapes and interiors very stereoscopically* (as opposed to the loathsome one-eyed camera image). Artists were very preoccupied with movement at the turn of the century: Marcel Duchamp’s Nude Descending A Staircase and that little futurist dachshund by Balla are famous examples. They came out of Muybridge’s photos of moving things. I think you’d enjoy reading Art & Illusion; there’s a little bit about it here, that Studiolum wrote (and the New Yorker cartoon is a good summary of Gombrich).
* (The top and bottom lines of the painting that’s stacked against the wall don’t line up on either side when they go behind the statue. Which is exactly how you see it stereoscopically, but not with a camera.)
I haven’t read Sartor Resartus, I guess I should.
Paranoid as well as a psychopath, then.
“I haven’t read Sartor Resartus, I guess I should.” I found it unreadable. So I tried again, wearing old Tam’s smoking cap. Still unreadable.
I’m surprised dearieme doesn’t appreciate Carlyle’s sarkyness. He was a brilliant, anti-Enlightenment hole-poker. Even the way the work starts makes it a book for our times:
The futurist dachshund gave me a fit of the giggles. The de-escalating nude at your links gives one more to think about, but not as much as Nude Descending Turkey.
I see that Muybridge was the subject of an opera by Philip Glass, who put the twee in tweedle-dum.
Of Geology and Geognosy we know enough: what with the labors of our Werners and Huttons
From Wikipedia:
Abraham Gottlob Werner ( 1749 – 1817), was a German geologist who set out a now obsolete theory about the stratification of the Earth’s crust and coined the now obsolete word Neptunism (and geognosy*, AJP).
…His former student Robert Jameson, who later became Regius Professor at the University of Edinburgh, founded the Wernerian Natural History Society in 1808 honour of Werner, which, while debating many aspects of natural history, was a bastion of the Wenerian view of the earth. (That’s why Carlisle knew of him, perhaps. AJP.)
…The basic concept of Wernerian geology was the belief in an all encompassing ocean that gradually receded to its present location while precipitating or depositing virtually all the rocks and minerals in the Earth’s crust. The emphasis on this initially universal ocean spawned the term Neptunism that became applied to the concept and it became virtually synonymous with Wernerian teaching, although Jean-Étienne Guettard in France actually originated the view. A universal ocean led directly to the idea of universal formations, that Werner believed could be recognized on the basis of lithology and superposition. He coined the term geognosy (knowledge of the earth) to define a science based on the recognition of the order, position and relation of the layers forming the earth. Werner believed that geognosy represented fact and not theory. They resisted speculation, and as a result Wernerian geognosy and Neptunism became dogma and ceased to contribute to further understanding of the history of Earth.
* That’s geognosie in German, not “geognossenschaft“, as I was kind of hoping.
Geognosy: Is it pronounced jog-nosey, geo-ger-nossy or geog-nossy?
It’s a long time ago, but not the mid-nineteenth century, but I believe I was taught something like this Neptunism, at school (primary school).
Geo-gno-SY.
Or rather ZY – the zzzz sound, not English “s”.
— I’m really wondering about the English pronunciation.
By one of those weird coincidences that occurred often in London, Werner was born in a house, now in western Poland, that had a picture of him in relief on the wall outside and a written prediction of his life.
Isn’t ventriloquism an auditory illusion?
Geognosy: Is it pronounced jog-nosey, geo-ger-nossy or geog-nossy?
OED says jee-OGG-nossy.
It’s a visual illusion, unless you buy the idea that a ventriloquist — en buktaler, in Norwegian — throws his voice. I think he just says “a gottle a geer” without moving his lips.
jee-OGG-nossy it is, then. Thanks.
Almost done reading a Russian novel called “Goat Song” from 1927 (not thrilled with it, seems pretty self-indulgently “experimental,” but I may just not be in the mood), and I thought I’d share this passage:
“Marya Petrovna, with a goat clasped in her arms, would run with the goat across the courtyard toward the place where Teptyolkin sat, and her husband, leaving behind his sublime experiences and the dissolving in nature, the absorption in the cosmos, would come out of the little garden and, after tossing two or three words back and forth with Marya Petrovna, go out past the gateway into the street.
“After such a state, Teptyolkin would feel the world’s sweetest charm. He would think even the sun was shining more brightly and, what was more, that everything in the world was bright, and besides, that he himself was a sublime person, worthy in all regards. Then he was seized with compassion for living creatures, and he would forgive all other people for their shortcomings.”
Thus we see the good effects of goats on humans.
The passage sounds to me more like mild sarcasm. Judging from that, I suspect Teptyolkin is a gushing old goat.
Thank you, Language. I do appreciate these reflections on goats from all over.
Grumbly, you just can’t believe it because you don’t know goats. Being around them will nearly always change your mood for the better — sometimes markedly.
I have nothing against goats, nor do I doubt their soul-healing powers. All I wrote was that the passage quoted by Hat seems mildly sarcastic to me. Do you disagree ?
It sounds like a description of a man who knows the convention of soul-healing goathood, and is rather preciously freshening up his self-image with it. Note “self-image”: the goats are not to blame.
Criticism similar to mine here was applied in the 17th century to the French dévots who preened themselves on conspicuous piety, aka holier-than-thou-ness. There was even a parti des dévots. Tartuffe, for example, was a faux dévot. The play – Tartuffe, or The Imposter – is intended to get the goat of religious hypocrites. Here again I think the goats themselves are above reproach.
My impression wasn’t of sarcasm. That was my point, I took it literally: being in the presence of goats can make me feel the world’s sweetest charm. For better or worse any cynicism I’m feeling disappears when I’m around them, it’s not relevant to the occasion. I don’t know whether goats heal the soul, though I’m sure they would never claim it themselves. But this is like a description of good food or the adjectives they use to describe wine (“blackcurrant with a hint of burnt plastic”), the only way to understand is to try it oneself.
I admit I’m prejudiced against French devout Roman Catholics of the seventeenth century — though I do try to keep it under control — so I’ll look into Tartuffe.
I’m quite keen on St Vincent de Paul, though, Grumbly.
“French devout Roman Catholics”: the only time in France that we’ve been asked to pay for a hotel room before occupying it was in that centre of devotion, Lisieux.
Fair’s fair, dearie. None of us has proof of your existence. If you paid me money, I’d be more inclined to believe in you. J’ai de l’argent, donc je suis, or something like that.
I clink, therefore I am.
Palpable hit, lh.
Although it might just be an auditory illusion.
With all due respect, Hat, the variant occurs to me: “I chink, therefore I am”.