The light is in our eyes...

Discussion in 'Physics & Math' started by Quantum Quack, May 21, 2017.

  1. Quantum Quack Life's a tease... Valued Senior Member

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    How about you try a simple reasoning test...
    "If what we see is interpreted from light data entering our eyes and extrapolated externally by our brains is what we see "objective" or "subjective"?
     
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  3. Quantum Quack Life's a tease... Valued Senior Member

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    It might come as a surprise to you all but this thread is not about cognition.It is an issue more fundamental.

    It is about what we create "out there" to be cognizant of after it is created.
     
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  5. Write4U Valued Senior Member

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    But we always see what has been created before we see it. We always see things in the past.

    We do not create anything physical by merely observing it. It was there before we observed it, always.
    That would be called a Tulpa.
     
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  7. DaveC426913 Valued Senior Member

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    I'm amused to see that even the OP has lost interest in discussing the topic.
     
  8. Quantum Quack Life's a tease... Valued Senior Member

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    this is the sequence of events I see..
    1. light enters eyes from source
    2. brain interprets light info and builds a 3 dimensional field of view and the illusion of source with vacant space. ( no cognition has actually taken place yet)
    3. brain then processes that field of view as if it were directly observing it. ( reflexive cognition, latency of vision processing)
    4. Processing via volition. ( deliberate, including focus and concentration )

    make sense to you?
     
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  9. Quantum Quack Life's a tease... Valued Senior Member

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    pardon?

    Please Register or Log in to view the hidden image!

     
  10. danshawen Valued Senior Member

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    There is always much, much more information in an image that you ignore than you process, just as there is light emitted in every direction, from every point of every object in the room or setting which you are currently in, as well as places hidden from you, which you will NEVER see.

    Are you interested in knowing about this? Knowing what, exactly? Why do you believe are you interested or 'cognizant' of anything at all, or for that matter, why is it that you must ignore so much more than you are even capable of processing?

    Do you have enough air, hydration? Where is your next meal coming from? Is there an explosive device hidden from view behind the monitor you are using? The only things we bother to process have a survival characteristic about them, whether directly or indirectly.

    What else do you now understand? You might as well be blind as well as ignorant without the ability to process a tiny fraction of what you see, remaining ignorant to all the rest of the torrents of information accosting you every second of every minute you are still alive.
     
    Last edited: May 31, 2017
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  11. Write4U Valued Senior Member

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    I'll just take #2
    When we build a 3 D field of view of an empty space, is the space already there before we cognize it?
    If so, then our interpretation is NOT an illusion, but an approximation. Can we agree on that?

    Illusion:
    and
     
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  12. Quantum Quack Life's a tease... Valued Senior Member

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    As I mentioned earlier, quite a few times, the amount of time involved in step #2 would generate a significant and noticeable time lag and energy drain ( if at all possible to begin with).
    There appears no time lag and there are no empirical based studies using the scientific method dealing with this particular issue that I can find.

    Since posting this thread none have come to light either. ( excuse the pun)
     
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  13. Quantum Quack Life's a tease... Valued Senior Member

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    The reason for using the term illusion is that what we see according to mainstream science is in fact a deception because.....

    Most persons would intuitively believe they are seeing the actual source and not a relatively accurate reinterpretation, or representation, of it.

    The light effect models ( that involve 'c') force people to take on a counter intuitive belief that forces them to distrust what they see.

    Ask a rifleman using iron sights shooting at a target say 400 meters away just how accurate the illusion has to be.

    So it can only be called a deception therefore an illusion IMO.
    But if you want to call it an approximation and it makes you happy .. by all means... but it is far from being an approximation (with some minor exceptions of course)
     
    Last edited: Jun 1, 2017
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  14. Quantum Quack Life's a tease... Valued Senior Member

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    Excellent post and points ... Dan.. Thanks. Very relevant...
    There is indeed a hell of lot of info reconstructed that we would never be cognizant of..... This supports the notion of event #2 mentioned:
     
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  15. DaveC426913 Valued Senior Member

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    1.
    Eyes of higher animals have a fovea - a central, small area of the retina where we do our primary seeing. It feeds about half of all the nerves. Everything else we see with peripheral vision. You'll notice, if you try to use your peripheral vision to do anything other than catch movement, it is actually rather difficult, compared to seeing with your fovea.

    So, when looking at the stars, you indeed see (and process) only a very small area of them - the rest is in far less detail.

    Try looking directly at this word on the page, now try to read the rest of the sentence - or any other part of the page - without moving your eyes from that word. It takes a very noticeable length of time to get it. (See how fast you can read it out loud, and you'll get the idea.)

    2.
    While you're busy concentrating on everything in your fovea, your brain is helping you out, by retaining imagery that's in your peripheral vision. Try this tonight, looking out at the stars. As you move your fovea around, just slightly, you will detect that the stars in your peripheral vision will shift and wobble. They'll fade out, then jump back in. This is your brain updating the "helpful" image with new information as the slow peripheral detectors notice it. (It's also partly that your retinal detectors are getting "tired", and get less and less stimulated over time. This is why we have saccades, so our detectors get refreshed.)

    3.
    Your eyes are constantly moving, even when you are staring directly at something. These movements are called saccades. They take only about 60th of a second or so, but your brain is completely oblivious to them. They occur faster than the brain's processing power.

    4.
    You blink all the time - more than you think you do. These blinks are also quite short - on the order of a 60th of a second. They also fall below the brain's threshold of processing.

    These are all signs that you do take a non-zero time to process information. Some quite fast, some quite slow. Your brain takes a large fraction of milliseconds to process things, and that's still faster than many of the things your vision-brain does together.

    This delay does not normally interfere with your vision in daily life - and one of the primary reasons for that is that your brain is going to a lot of effort for you to not see any lag.

    But you can "hack" your vision. You can try various experiments (such as the ones above) to show, beyond any doubt, that
    a] your eyes take time to register things (persistence of vision, about 1/10th of a second)
    b] your brain can look at (and process) only so much information at a time
    c] there is a detectable delay between capturing an image and processing it, and finally, that
    d] a large part of the your brain's processing is devoted to making you think you are seeing an accurate rendition of reality (both in static images and over time).

    There are many, many books on the subject.
     
    Last edited: Jun 1, 2017
  16. Quantum Quack Life's a tease... Valued Senior Member

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    yes many ... about what I referred to as step 3...and 4
     
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  17. DaveC426913 Valued Senior Member

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    As for seeing distance, you cannot see distance directly.

    There are many, many hints that we use to determine distance. They fall into three categories:
    1] Stereoscopic vision. Having two eyes gives us parallax. The brain uses the information of how our two eyes are angled with respect to each other to judge distance.
    2] Visual familiarity. We know how big trees should be.
    3] Distance clues. I can see that object is sitting on a field of grass whose distance I an estimate. I can see that it is hazy and low-contrast in the distance. I see it is moving slowly across my vision, hinting that it may be far away.

    It is notoriously difficult to determine the distance of things such as UFOs in the sky. All three of these techniques fail when looking at an object that is too far away for parallax, of unknown makeup, and is not proximal to any known objects.
     
  18. Quantum Quack Life's a tease... Valued Senior Member

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    so how is the object visually there to be seen to begin with?
     
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  19. DaveC426913 Valued Senior Member

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    Photons from the object follow relatively straight lines in all directions. Some of them enter our eye. Where they intersect our retina, they form a 2 dimensional image, including every other thing around it (such as blue sky and buildings on the horizon). This image is transferred to our brain, where it is our perception of our field of view.
     
  20. DaveC426913 Valued Senior Member

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    This is all correct.

    We have no experience of what is actually out there. And this is why our vision can be hacked, with something as simple as a prism. A prism will put an image of an object into our field of view despite that object being somewhere completely different. Our eyes cannot tell the difference (except by clues, such as seeing the prism itself, and being smart enough to know what a prism does).

    When I refer to "tracing the ray back", I don't mean literally; I mean our brain sees the object at point X in its field of view and assumes the object is actually there at that point in our field of view. If a virtual object is projected between two other real objects, our brain will think all three are side-by-side. Our brains have learned this is trustworthy, but we can fool it.

    As to whether we are actually seeing the source - that is a mater of semantics. For 99.9% of our daily lives, objects are where we see them to be - and we can call that seeing the source. But an optical physicist - or anyone with a prism and a mischievous bent - know that the other .1% of the time our vision is imperfect.
     
    Last edited: Jun 1, 2017
  21. Write4U Valued Senior Member

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    I am happy that you can accept the term "approximation" as an alternative to "illusion".

    IMO, the brain is a bio-chemical computer that tries its best to make *sense* of incoming data.
    And I gladly accept that sometimes the brain is fooled by an "optical illusion", especially when it processes previously unknown data and has only limited comparative experience.

    We usually know the size of an object by comparing it to a known object. Even at a distance we can tell the approximate height of a tree, when we see a person stand beside it. We know the average height of a person to be about 6', so if the tree appears to be 3x times the height of the person, our brain can extrapolate that the tree must be about 18' high.

    However if we create a false horizon, it can interfere with the brain's ability to make accurate comparative measurements.

    And as Dan mentioned, we see things selectively. A perfect example of that:
    https://www.bing.com/videos/search?q=invisible monkey optical illusion&view=detail&mid=647089DAF1C2565C4679647089DAF1C2565C4679&FORM=VIRE
     
    Last edited: Jun 1, 2017
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  22. Seattle Valued Senior Member

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    When I was a kid on vacation we went into a "Fun House" where water flowed uphill and where it was hard to stay on the floor and other such effects.

    The interior of the house was actually build at an angle and sometimes you were walking on the floor when it appeared you were walking on the walls, etc.

    If the visual cues are just right it's easy to fool our eyes/brain.

    If you're not very smart it's easy to do this all of the time.
     
    Last edited: Jun 1, 2017
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  23. danshawen Valued Senior Member

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    Persistence of vision or memory. It's that Dalvador Dali painting with the large melted stopwatch draped over a tree branch. Wow. That image persisted a long time, didn't it?

    You should paint a picture of what it is you see, QQ. Do you know how much that painting is worth?
     

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