That is cool!
When I first looked at it I only saw one black dot at a time.
However looking at it for a while I started to see more and more and after a few minutes about 7 were always visible in the in fixed positions plus two still jumping about.
Isn't it? What fascinates me about this illusion is how sharply defined the dots are when I can see them. And then, a moment later, that same dot may be completely invisible. 😱
It gives us a little peek behind the curtain - our brains, locked in perpetual darkness inside our skulls, are running complex algorithms to try and figure out what the outside world looks like.
The algorithms work pretty well if you're chasing a deer through the savannah with a spear in your hand. But they fail spectacularly with so many optical illusions!
-Gnobuddy
I can see people standing in front of me, but I can't see people standing behind my back! What an "illusion"! (how about using mirror?)
When I was a kid, I didn't understand about light wave refraction, I didn't understand about change of speed of light in different medium, yet I knew how to hunt fishes with spear (without anybody telling me how)...
And the major problems with deer hunting is not the visual. There are several well understood Physics involved. We know that there is time T second for a spear moving from our hand to the destination. And because the destination is moving, we must calculate the displacement of the destination within T second. We must predict or interpolate the future position of the deer...
My point is, what is the problem here?? It's just like almost anything else in life: we have to learn! May be the reason this is interesting is that because it's regarded as "illusion", a very deceptive thing. But the measure of deceptive level is very subjective!
An illusion may be deceptive for someone but not for someone else. What is more dangerous and deceptive is something that we don't know "anything" about. There are many things like this in life... Things beyond one's ability to comprehend...
This is a talk I've posted before (link skips the a couple minutes of introduction) The first three minutes or so describe an A-B test:
https://www.youtube.com/watch?v=BYTlN6wjcvQ&feature=youtu.be&t=3m19s
And there's actual aural demonstrations - sometimes it's a lot easier to hear what lyrics are when you can read them right in front of you.
https://www.youtube.com/watch?v=BYTlN6wjcvQ&feature=youtu.be&t=3m19s
And there's actual aural demonstrations - sometimes it's a lot easier to hear what lyrics are when you can read them right in front of you.
Many years ago I came a cross a pretty amazing visual illusion mentioned in a book.
It was something like this... there was a black and white pattern printed on the page that looked (as I recall) remarkably like todays Q codes. What you did was to place a mirror at 90 degrees to the edge of the pattern and then arrange yourself so that you stared with one eye at the page and have the other eye staring at the reflection. Tweak the mirror position so the two images overlay visually and just keep staring.
After a time, and that could be several minutes, your brain suddenly makes sense of it all and a 3D image suddenly appears. In the example I had it was like a tower of boxes, each smaller than the last positioned one on top of the other. The image you finally saw was vivid and lifelike and had a true 3D quality. Look away and then back again and the effect was lost as your brain has to recalculate what is happening.
Reverse the eye/mirror combination and the effect was the same but now the 3D effect was in the other direction, in other words the boxes were now disappearing downward but still with the 3D effect.
Apparently the brain needed to do millions upon millions of 'calculations' to make sense of what it was seeing. Come back to it all a day later and you could acquire the image much quicker.
I've never been able to search or find what this effect is and to find any examples on the web.
Edit... it was more of a staircase than boxes. It must be nearly 20 yrs ago that I first saw this.
It was something like this... there was a black and white pattern printed on the page that looked (as I recall) remarkably like todays Q codes. What you did was to place a mirror at 90 degrees to the edge of the pattern and then arrange yourself so that you stared with one eye at the page and have the other eye staring at the reflection. Tweak the mirror position so the two images overlay visually and just keep staring.
After a time, and that could be several minutes, your brain suddenly makes sense of it all and a 3D image suddenly appears. In the example I had it was like a tower of boxes, each smaller than the last positioned one on top of the other. The image you finally saw was vivid and lifelike and had a true 3D quality. Look away and then back again and the effect was lost as your brain has to recalculate what is happening.
Reverse the eye/mirror combination and the effect was the same but now the 3D effect was in the other direction, in other words the boxes were now disappearing downward but still with the 3D effect.
Apparently the brain needed to do millions upon millions of 'calculations' to make sense of what it was seeing. Come back to it all a day later and you could acquire the image much quicker.
I've never been able to search or find what this effect is and to find any examples on the web.
Edit... it was more of a staircase than boxes. It must be nearly 20 yrs ago that I first saw this.
Well if your brain would 'forget' how to do calculations you'd be dead very, very soon.
After all that is what a brain does: Take in outside stimulus, filter it according to inherited or learned algorithms (may be not the best word but the best I can come up with right now) and use the result as a basis for calculationswhich may or may not lead to actions.
If it does lead to an action many thousands of calculations follow in order to execute it.
After all that is what a brain does: Take in outside stimulus, filter it according to inherited or learned algorithms (may be not the best word but the best I can come up with right now) and use the result as a basis for calculationswhich may or may not lead to actions.
If it does lead to an action many thousands of calculations follow in order to execute it.
Many of so called "illusion" is only an illusion for those who are not aware of the Physics related. Once it is experienced or understood it is not deceptive anymore. Often, it is a simple Physics, that becomes part of our daily knowledge.
This statement: We can see people in front of us but we can't see people behind our back. Everybody know that, so it is not illusion, isn't it? Now how about the "12-dot illusion", is there anything against basic Physics there? None. It is no different than the fact that we cannot see people behind our back...
So my first point is: (1) Everything is an illusion for the unaware. Many of said illusions are deceptive only for those unaware of the facts. Often, once the Physics is understood, it is not deceptive anymore.
What makes the above "illusions" so meaningless for me is:
My second point: (2) In contrast to the above "illusions", there are many other "things" in life that are so deceiving that most people do not aware that it even exist.
Test equipment and test techniques have come a long way since that demo.
But testing is about measuring differences, it's not about what humans think of those differences.
The problem is that you - and I, and everyone else - is seeing something that isn't actually there.
If one person sees something that doesn't exist, we call him mad. If all of us see it, we call it an optical illusion. It's "normal" for our defective human brains.
Our brains and senses aren't perfect. We see things that aren't there. We hear things that aren't there. There is a vast body of documented evidence about these things.
And yet, audiophiles insist that the extremely subtle things they think they hear are real, even when they cannot be measured - using instruments known to be much more accurate, reliable, and sensitive than the human ear.
But we know our hearing is unreliable, just like our ears. Good enough to detect crude differences, sure.
You can learn to allow for the refraction of the water altering the apparent position of your spear. But you cannot learn to stop seeing optical illusions. Your brain (and mine, and everyone else's) fails to interpret correctly what is in front of your eyes; so you see things that don't exist, or fail to see things that do exist.
Show me a collection of people who do not see optical illusions, and I'll agree. Out of a population of 7.5 billion humans, surely it will be easy to find at least 7.5 million people like this, immune to optical illusions; that's only 0.1% of the population.
But nobody has ever found such a person!
Totally agree, but the performance of a simple audio reproduction chain is not one of them. It has been well studied by many geniuses, and was very well understood even fifty years ago.
-Gnobuddy
Gnobuddy, I think you're misunderstanding Jay.
You can never learn to see behind you, but you can learn to look around to see what's behind you. You can never learn to see all the black dots at once, but you can learn to see each one my looking right at it. If you leave the room and leave your baby in, to your baby you don't exist anymore, but over time your baby learns that you exist even when you're not there.
You can never learn to see behind you, but you can learn to look around to see what's behind you. You can never learn to see all the black dots at once, but you can learn to see each one my looking right at it. If you leave the room and leave your baby in, to your baby you don't exist anymore, but over time your baby learns that you exist even when you're not there.
Wrong .... nothing !
I have ran the A/B frontend (below 1). Same 20ppm as a full discrete design - same
perfect "sound". Lesser TL0xx's do not have the same low THD20K. OPA's were
the champs in all my IC designs.
Class A (below 2) .... same perfection. The OP stage reflected the quality of the
IC.
DC offset and thermal stability were better with IC designs. The only drawback was
the tweaks required with the current requirements associated with (different) IC's.
I HAVE heard(tested) the difference in "old' (TL0xx/LM353) versus the "OPA's" in these circuits.
Mostly HF definition.
This could be application dependant.
Yikes ... 80% of this thread is totally subjective 😱 .
OS
I have ran the A/B frontend (below 1). Same 20ppm as a full discrete design - same
perfect "sound". Lesser TL0xx's do not have the same low THD20K. OPA's were
the champs in all my IC designs.
Class A (below 2) .... same perfection. The OP stage reflected the quality of the
IC.
DC offset and thermal stability were better with IC designs. The only drawback was
the tweaks required with the current requirements associated with (different) IC's.
I HAVE heard(tested) the difference in "old' (TL0xx/LM353) versus the "OPA's" in these circuits.
Mostly HF definition.
This could be application dependant.
Yikes ... 80% of this thread is totally subjective 😱 .
OS
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Funny you should mention those two!
I once bought two electronic crossovers (BSS FDS360), one for left and one for the right channel, but I could never get the LR balance right and had to adjust it from song to song.
Was driving me nuts until I opened them up and realised that one was full of TL072s and the other one was populated with LM353.
Changed them all for OPA2134 and all has been well ever since with a steady stereo image.
Subjectively audibly better than before. ;-)
Kick the can down the road again...
could be great lyrics for a song.
Anyhow, IF you take a number of pieces of commercially designed and DIY gear circuits and sub in different opamps, what do you get? All the same sound? Or not.
Some here think there is nil sonic difference between the 5534 and others, such as the AD797, the National or TI/Burr-Brown ultra low distortion devices.
Raise ur hands if you think that, or you hear that based on your experience?
That seems to be what is being said by many.
Personally, I don't care much if they DID all sound the same. It would make things so much simpler and easier. They don't. If you don't hear it, then your life is that much easier and simpler. More time listening and less time not liking what you are hearing.
Anyone who wants to stop over is welcome (contact me first, of course) and we can swap opamps. (we can swap out just one, if you like) It will be single blind, only you won't know what is what. I will. I won't let on. We can dim the lights if that will help you.
IF there are dynamic & transient artifacts that are causing the "difference" that (so far) everyone who has been here to try this HAS heard, I've not identified them. Should they exist, that would be great, and they can be eliminated.
If you want to send me a board/circuit that is essentially a buffer or <x10gain to try out, to swap opamps and get listeners (victims) to listen to (that way YOU will be sure that IF the sound changes it won't be the faulty layout/design/engineering here causing the problem), contact me.
I'll be 100% forthright and truthful - if no differences are heard, then I'm more than pleased to say it.
I've got no dog in the fight - just gimme some truth!
_-_-bear
could be great lyrics for a song.
Anyhow, IF you take a number of pieces of commercially designed and DIY gear circuits and sub in different opamps, what do you get? All the same sound? Or not.
Some here think there is nil sonic difference between the 5534 and others, such as the AD797, the National or TI/Burr-Brown ultra low distortion devices.
Raise ur hands if you think that, or you hear that based on your experience?
That seems to be what is being said by many.
Personally, I don't care much if they DID all sound the same. It would make things so much simpler and easier. They don't. If you don't hear it, then your life is that much easier and simpler. More time listening and less time not liking what you are hearing.
Anyone who wants to stop over is welcome (contact me first, of course) and we can swap opamps. (we can swap out just one, if you like) It will be single blind, only you won't know what is what. I will. I won't let on. We can dim the lights if that will help you.
IF there are dynamic & transient artifacts that are causing the "difference" that (so far) everyone who has been here to try this HAS heard, I've not identified them. Should they exist, that would be great, and they can be eliminated.
If you want to send me a board/circuit that is essentially a buffer or <x10gain to try out, to swap opamps and get listeners (victims) to listen to (that way YOU will be sure that IF the sound changes it won't be the faulty layout/design/engineering here causing the problem), contact me.
I'll be 100% forthright and truthful - if no differences are heard, then I'm more than pleased to say it.
I've got no dog in the fight - just gimme some truth!
_-_-bear
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Of course our brains have limitations. Obviously. But why do you call it "defective"...
Even worse than illusion is hallucination. Have you ever heard about Schizophrenia? Alzheimers? Dementia? Parkinson's Disease?
Define extremely subtle things! And I don't think that anyone ever said that such subtle things cannot be measured. Ime (where I have never met anyone with better ears), everything I heard can be measured.
Problem is (1) we don't have agreement on the thresholds. I can obviously heard -54dB on the klippel test, easily. So that is not the threshold for me. (2) People don't know what to measure. Usually, you cannot make 2 amps (for example) to have the same set of measurements, NEVER. This is important as you don't know which measurement causes the audibility.
Yes, our hearing is unreliable. Our brain too!
As long as we can see or understand that there is an "illusion" so that we wont be deceived then it's fine.
Our brain can interpret it correctly as an "illusion".
The point is that we can understand that an illusion is an illusion.
That "12-dot illusion", let's see the extreme cases. Case #1: Make the distance between the left-most dot and the right-most dot 5 km apart. Can you see the dot? (this is the analogy like putting the dots behind your back). Case #2: Make the distance between the left-most dot and the right-most dot 5 cm apart. Can you see the dot? (What is so new about focal point? Anybody know how to implement this knowledge for quick reading?)
I was talking about the "real illusion" that people do not see as illusion. I was not talking about audio measurement as something beyond one's ability to comprehend. I was talking about something like logical fallacies or any other psychological things, where most people may not be aware of the fallacy for the rest of their lives.
BTW, here is a simple illusion (picture attached), making use of facts regarding gradual color change (called gradient) and contrast. If this illusion is new for you then ask yourself "is it possible that square A and square B has the same color?"
Now, the harder question: "Can you visually see that square A and square B has the same color?". I can 🙂
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Shaddows and things in the shadow is also crucial to this illusion, critical to how we see things.
Without printing it and folding it most if not all perceive them as different shades, are you saying you see them as the same shade of grey without doing that! Dubious.
Without printing it and folding it most if not all perceive them as different shades, are you saying you see them as the same shade of grey without doing that! Dubious.
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