Whew! Christmas is a lot of work. I’m glad it’s over.
Come on. Somebody has to know this. It’s not just cyan and red. The same thing happens with red and blue. Why am I seeing black? If I look through the prism at the top center image in the direction of the red arrows, this is what I’m seeing. Why black? I can’t figure it out.
That would make sense. The blue and red separating in one direction but overlapping in the opposite creating the magenta. With your eye, you see green, blue, a light and dark magenta and then red. In the other direction, there’s a dark blue, light blue, green, black and then red. What’s the cause of the green? Do you know? Maybe because the blue refracts more than the green?
"A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies."
It’s not a spectral line of any sort, but nevertheless, your answer led me to the correct one. So, for that, I am grateful.
It’s caused by refraction and of course, our perspective—our subjective view (the reversed spectrum). Our subjective view causes the blue to be deflected towards the apex and the red towards the base.
The only thing that I can’t figure out, though, is this video. It’s not showing the reversed spectrum viewed through a prism but you can look for yourself. The spectrum is always reversed through a prism. Something is odd about the video, though. Take a look at the setup. Look at the angles. Here’s a superimposed image of the setup. It’s as if the perspectives are flipped horizontally. Do you see what I mean?
If I’m right, it’s odd, isn’t it? If I’m right, our subjective view literally changes the outcome of the results—of the colors that we see. Our perspective is what separates them or brings them together.
At least a little of my vertigo and disorientation when entering the thread has abated due to finally getting that there's [perhaps] an underlying background theme to this in terms of Goethe versus Newton, or art versus science. Goethe believing that color arose from yin/yang like interactions of light (white) and dark (black). Thus the focus on "colored fringes along boundaries".
Goethe was historically dismissed by physics, but others still consider his work relevant for one reason or another -- including his taking into account more complicated environmental effects and seemingly anticipating the contribution of human perception (the contingent circumstances and subjective elements of brain and optical system processing). However, it's possible that Newton may have actually addressed some things that Goethe missed or was unaware of. Cotterell Brian: "...As Newton noted the effect is the same if a white rectangle on a black background is viewed through a prism and also the colours that are visible when there is a black rectangle on a white background. Goethe discussed the identical problem [...] but whereas Newton gave a simple explanation of the phenomena, Goethe only wrote vaguely of 'the movement of the dark against the light.' he also remarked that 'an objective experiment with a dark object has hitherto scarcely been thought of.' Unless Goethe ignored much of what Newton wrote [...] he could not have read it very thoroughly." --Physics And Culture ... Page 270
"Goethe was aghast that Newton took the results of this experiment in particular and generalised it to all of nature. Yes light behaves like this, in that specific situation i.e. of a reasonably well defined beam of white light entering a highly specialised object (the prism). But to then extract from this the entire nature of colour and light seemed to Goethe an extraordinary conceit. It seems incredible that in all the years since it's Newton who has ridden the white horse of righteous knowledge, and Goethe has worn the dunce's cap, given this entirely practical and sensible objection.
For Newton again, white light comprises all of the colours of the rainbow. They are its components, which refraction through a prism reveals as the different wavelengths are (apparently) separated out. Of course there is much more to the Newtonian theory, which there isn't space for here, but this point is critical. For Goethe on the other hand it was all about the interaction of light and dark, with colour representing various degrees of darkening of light. This seems a bit weird at first, but if you read Goethe's section on coloured shadows you'll start to see where this is coming from. For example if you light a candle in twilight, and place a sheet of white paper on the opposite side of the candle to the setting sun, at a certain point in the setting of the sun the shadow the candle casts on the white paper will turn a breathtaking blue. https://doorsausage.blogspot.com/2009/06...oethe.html
[...] To begin, we need to consider the concept of boundary colors—these are colors that appear when you look through a prism (or a transmission diffraction grating) at contrasting colors. If you hold a prism up to your eyes and view the world around you, boundary colors appear at the edges of objects and exhibit a very particular structure and color order. For purposes of simplicity, this phenomenon is most often observed by looking at the boundaries between black and white shapes." https://www.refractionsblog.com/single-p...s-of-Color
One of the strangest and most fascinating of Goethe’s investigations involves what is known as the dark spectrum (also known as the inverted spectrum and the Goethe spectrum.) What at first sight might seem like an absurd and logical impossibility, the refraction of darkness has, it turns out, some interesting and curious things to say about our perception of color. The typical spectrum, as exemplified in the work of Isaac Newton, involves passing a beam of white light through a prism, and viewing the resultant array of colors that pass through the other side. Newton coined the term spectrum (from the Latin, meaning apparition) to describe this well-known phenomenon, and labeled the colors of the spectrum, red, orange, yellow, green, blue, indigo and violet. Goethe, on the other hand, felt that darkness was just as important as light, in the creation of color. In fact, he felt that all colors were an admixture of light and dark, an idea that went back to Aristotle. In his Theory of Colors (Zur Farbenlehre) of 1810, he proposed a series of experiments that he felt provided a more complete and comprehensive theory of color than Newton’s. One such experiment posited the idea of passing darkness, not light, through a prism, and noting the particular ‘spectrum’ that appeared on the other side. What Goethe found was a spectrum that was composed primarily of what we would today describe as cyan, magenta and yellow with intermediate colors of red and blue.
From the standpoint of color science, darkness is the absence of light, and so cannot be refracted. To be fair, Goethe did not believe that the visible colors of his, or Newton’s spectrum for that matter, were the result of differential refraction. Instead he believed that color was an admixture of dark and light, as mentioned previously, and occurred only at the boundaries or edges of light and dark. He maintained that what we see in the middle of each of the two spectra, green (Newton’s) and magenta (Goethe’s), resulted from the mixing of their borders. Goethe believed that these two spectra proved the polarity and complementary nature of light and dark, a theme picked up many of his followers and adherents. No doubt they do display a striking symmetry: one light, one dark, one composed primarily of the additive primaries (RGB) the other of the subtractive primaries (CMY), and both seemingly produced in similar ways. But the effect exhibited in the dark spectrum, is produced by the light that surrounds the dark shape, as it refracts differentially. Because the darkness is a ‘gap’ in the light passing through the prism, each refracted wavelength will contain its own corresponding ‘gap’ and will displace differently, according to its wavelength. By additively combining the remaining wavelengths found at such gaps, the resultant colors will appear, as can be seen in the following diagram." https://www.refractionsblog.com/single-p...n-of-color
[...] Goethe's scientific interest in color was inspired by the natural optical phenomena and the coloristic traditions of Renaissance painting that he encountered during his first journey to Italy (1786-88). Goethe's first publication on color theory, Contributions to Optics followed a few years later. The Contributions centered around a series of experiments in which Goethe viewed various painted images on paper through a prism. Like Newton before him, he observed colored fringes along boundaries. Unlike Newton, however, Goethe systematically varied the experimental conditions--the shape, size, color, and orientation of the images viewed; the refracting angle of the prism; and the distance of the prism from the figure--to determine how they influenced what he saw. https://physicstoday.scitation.org/doi/f.../1.1506750
The synthetic stage of Goethe’s investigation is illustrated by his experiments on the colored fringes that appear when gray and colored images on various backgrounds are viewed through a prism. Figure 3 shows how part of one of Goethe’s diagrams (see the cover of this issue), from Theory of Colors, looks through a prism with its refracting angle held downward. Experiments with squares in different shades of gray against white and black backgrounds showed that the intensity of the colored fringes increased with the lightness contrast at the boundary. More complex phenomena were seen using colored squares, which exhibited fringes with new colors not seen in the previous experiments. Goethe argued, quite plausibly, that those new colors were due to the mixing of the elementary fringe colors with the colors of the squares themselves. Goethe regarded that mixing as the true explanation of Newton’s observation that a red square, viewed through a prism against a black background, appears displaced slightly higher than a blue one, as seen in the upper right of figure 3. Whereas Newton had adduced this observation to prove that different colors of light have different refrangibilities—the first proposition of his Opticks—Goethe saw it as merely a special case of the more general law of colored fringes. https://physicstoday.scitation.org/doi/f.../1.1506750#
[...] Whereas Newton traced a beam of white light passing through a prism and fanning out into the colours of the rainbow as it was refracted, Goethe looked through a prism and was concerned with understanding what his eye subjectively saw. He created a sequence of experiments which produced what appeared to be anomalies in Newton's theory. What he was carefully illustrating concerns limitations accepted when following a scientifically objective approach. Newton was concerned with the description of ‘facts’ derived from the analysis of observations. Goethe was concerned with the synthesis of meaning. He then went on to describe subjective techniques for training ‘the mind's eye’ to work efficiently in the subjective world of the imagination. Derided as ‘not science’, what he was actually describing is the skill which is central to creative design. https://www.sciencedirect.com/science/ar...via%3Dihub
[...] Textbook accounts of the history of physics usually highlight discoveries involving simple systems, that is, those consisting of relatively few interacting elements. Such systems lend themselves to study by means of isolated experiments designed to demonstrate directly an underlying physical principle. Most of the celebrated experiments of physics, from Galileo's with balls on inclined planes to Robert Millikan's with oil drops, are of this type. The physicist studying a simple system deliberately removes complicating influences, like an intensely focused road builder cutting a straight road with little interest in the surrounding landscape.
Newton's investigations into optics were guided by the metaphysical belief that color was merely a subjective correlate of mechanical properties of light rays. He therefore abstracted from the complex world of normal visual perception, working in a dark chamber illuminated only by a single sunbeam. The system he studied was thus a simple one, comprising entities of a single kind--rays with diverse refrangibility--whose mutual interactions, such as color mixing, were purely superpositional. Newton's approach was entirely reasonable given his aim: His mathematization of light and color could best take flight from a few particular effects. But the price paid was that his experiments had only limited relevance to color as usually perceived.
Physicists studying complex systems that consist of numerous interacting elements face a task different in kind from that confronting Newton. They often start with a multitude of empirical findings whose interconnections and underlying principles are unclear. They must use experiments not so much to demonstrate propositions as to develop the concepts needed to make sense of multiplicity. The traditional isolated experiment is of little help here. Instead, the student of complexity must be an explorer, performing numerous laboratory or numerical experiments under different conditions, sufficiently "close" to one another that no important feature of the behavior is missed. Such a physicist is not so much a road builder as a mapmaker, whose principal interest is the physiognomy of a complex landscape.
The role of relative complexity in motivating the choice of experimental strategy is clearly illustrated by the contrast between Newton and the exploratory cases we have discussed. Goethe and Land were interested in color as an irreducible quality, not as an epiphenomenon. Recognizing that the human eye and the external world constitute a complex interactive system, both chose to explore it under diverse aspects, performing literally hundreds of experiments during their careers. The result was a deeper understanding of the complexity of the conditions under which colors appear in the world of everyday experience. Faraday also studied phenomena that exhibited a bewildering diversity and complexity in which many interacting factors played important roles: the shapes of wires; the strength of magnets; the speed and direction of the relative motion between them; and the strength, direction, and time-dependence of currents. Although the laws describing these phenomena may seem simple to us today, this simplicity was not evident to Faraday, who chose to follow an exploratory path. https://web.archive.org/web/200302190339...7/p43.html
(Dec 28, 2019 11:03 PM)C C Wrote: At least a little of my vertigo and disorientation when entering the thread has abated due to finally getting that there's [perhaps] an underlying background theme to this in terms of Goethe versus Newton, or art versus science. Goethe believing that color arose from yin/yang like interactions of light (white) and dark (black). Thus the focus on "colored fringes along boundaries".
I wish it was that easy. I think the problem is, is that everyone confuses the inverted (Goethe’s spectrum) with the reversed spectrum, which is an entirely different phenomenon.
From your link...
Quote:Goethe believed that these two spectra proved the polarity and complementary nature of light and dark, a theme picked up many of his followers and adherents. No doubt they do display a striking symmetry: one light, one dark, one composed primarily of the additive primaries (RGB) the other of the subtractive primaries (CMY), and both seemingly produced in similar ways. But the effect exhibited in the dark spectrum, is produced by the light that surrounds the dark shape, as it refracts differentially. Because the darkness is a ‘gap’ in the light passing through the prism, each refracted wavelength will contain its own corresponding ‘gap’ and will displace differently, according to its wavelength. By additively combining the remaining wavelengths found at such gaps, the resultant colors will appear, as can be seen in the following diagram.
It’s one thing to contemplate the boundary colors that are produced from the light that’s surrounding a dark shape, but when thinking about the darkness or the colors that are produced from refraction when looking through a prism is a little different and depends on the fact that the spectrum is reversed in order. That, in and of itself is what causes the red and blue to diffract in opposite directions. It’s what causes them to combine or separate when looking through the prism.
Newton was aware of it. He mentioned it in his notes (number 14). He said, "Prismalicall coulours appear in the eye in a contrary order in which they fall the paper." He doesn’t provide a reason, nor does he mention it again, but he touches on it in his response to Robert Hooke regarding thin film.
The explanation for the reversed has been a contention between myself and this grumpy old curmudgeon. The whole story really does fit the Alice in Wonderland theme with the rabbit hole, behind the looking glass, etc. He’s always mad. So, I dubbed him the Madhatter. He posted the question on YouTube years ago and I answered it. This was my answer.
I was satisfied with my answer and every physicist seemed to agree with me, but he keeps pulling me back in. Not too long ago, he found another guy that used to work at Motorola aligning chroma panels. This guy has credentials, too. He agreed with him that the red is always deflected towards the base and the blue towards the apex and supposedly, they’re summiting this as a new law, but a law has to describe and explain the phenomenon. According to the grumpy guy, both of them believe that my answer is incorrect.
It’s rarely mentioned, and quite a few people are still unaware of it, but believe it or not, I was able to find it in an old children’s book.
It’s just a puzzle that I pick up from time to time. I was going to invite him here to debate the explanation but he’s not speaking to me at the moment. Go figure.
Do you think that my explanation for the reversed spectrum is correct, C C?
C CDec 31, 2019 06:37 AM (This post was last modified: Dec 31, 2019 06:46 AM by C C.)
(Dec 31, 2019 12:14 AM)Secular Sanity Wrote: . . . Do you think that my explanation for the reversed spectrum is correct, C C?
Remember, I said earlier that my vertigo and disorientation in this thread have only partially diminished, SS. I don't know what "reversed spectrum" is supposed to mean. And "inverted spectrum" still only registers officially for me as a philosophical thought experiment that Chalmers and others have kicked about for years, despite these "Goethe explainers" apparently recruiting the label as a synonym for G's "dark spectrum".
Does the RS outcome resemble something akin to a reversed and inverted image via camera obscura, but involving the order of spectral color components instead?
There's a distinction (which I'd like to maintain) between a psychological and ocular model of color that Goethe might have indeed apprehended something about (or at least his work is interesting, regardless), and what physics measures as "actually" outside the head/body. (I.e., the non-phenomenological version of color, also minus those extra imaginary additions introduced by biological processes and perspective.)
As the narrator in the video below says at one late point, "Science can explore colors without observing them". It'd probably be more accurate to say it strips away the personal experience of color and leaves behind or substitutes an abstract description (quantitative data and principles and wave/particle entities amenable to those) which it can tinker with on paper, chalkboard, text-screen.
(Dec 31, 2019 06:37 AM)C C Wrote: Does the RS outcome resemble something akin to a reversed and inverted image via camera obscura, but involving the order of spectral color components instead?
You’re asking the right questions, which indicates that you’re not as spun around as you might think.
It’s not akin to the camera obscura. The difference is, is that the prism creates a virtual image and the camera obscura creates a real image. You can think of it this way. A real image involves the actual light rays. A virtual image is created by us tracing the real rays that emerge from a lens, prism, mirror, etc., back to an apparent point of origin, not a real one. In other words, the light rays themselves are not creating the image. A virtual image cannot be displayed onto a screen or wall because it is us, who is tracing the rays back in a straight line.
The image created by the camera obscure is upside down because the actual rays cross over each other. The image created behind the prism is upright and not flipped like a mirror image because they don’t cross over and they’re not reflected back towards our eyes. The technical term for it is tranverse chromatic abberation. We trace the light rays back as indicated in the image below (courtesy of a member on physics forums).
Like I said earlier, what makes it even more confusing is that you, not only have to think about the reversed spectrum and the color being deflected in opposite directions, but you also have to remember that the background comes into play. The background light or lack of will obviously affect the outcome. Similar to the summary of the video that you just posted. Great find, BTW. I loved it!
I’ll show you a brief teaser of some unusual and interesting observations regarding the background color. I’ll post some more later but I’ll let you get reoriented first.
I agree that the blue and red appear to deflect in opposite directions but the only problem I have with the idea that the black line is caused due to the separation of the two having no light in between them is that I can see a very faint, deep, dark purple in the black area underneath where there is yellow in the white portion. If I gradually lighten the background, you can start to detect a faint yellow. As I darken it, the faint yellow gradually turns into a barely noticeable deep dark purple.
As you can see, when the red and blue are deflected towards each other with the red displaced towards the base and the blue towards the apex, the blue bleeds over into the red creating magenta, but…the white background is also displaced creating an invisible blue that bleeds over into the red area creating magenta.
Remember what I said about Nietzsche and your own biases? Well, this is why the subjective and objective prismatic experiments are so damn dizzying. You have to keep switching back and forth between the two. Sort of puts a whole new spin on the eye of providence, doesn’t it?
With single ink, green gets absorbed by the applicable substance and reflects red and blue to get merged into an imaginary color by our optical system.
So now that maybe prisms, Goethe, the interference stuff and whatever else is no longer distracting me to wonder what sign I badly misread back at a forked road, I finally get that you're offering a remedy to how the rays would meet to combine as magenta (etc)? And your opposite directions fits the bill for making that happen. (If there are alternatives then the fysicks world needs to speak up about them clearly for a change instead of mumbling and waving hands in the background.)
Is that what that is -- his name on YouTube, or something else? At any rate, great work, ace investigator D__st_r ..... Er, SS -- at yanking the chain of The Great and Amazing Poradin and exposing his hopefully less than sinister aims and legerdemain, with a solution!
As for black lines... I've been taking everybody at their word that they're seeing black lines (in a different context than the absorption lines of spectroscopy).
Maybe it's analogous to Rorschach blots.
One person says: "I see Standing Buddha in that pattern."
I say: "Okay."
If several others also perceive Standing Buddha, then I'm even more okay with going along with it.
I mean, I'm the one who can't even see the colors that are supposed to be generated in both B&W animated and static optical illusions, so if there are black lines and/or lines that change with perspective, I'm game with it.
(Jan 2, 2020 11:15 AM)C C Wrote: With single ink, green gets absorbed by the applicable substance and reflects red and blue to get merged into an imaginary color by our optical system.
So now that maybe prisms, Goethe, the interference stuff and whatever else is no longer distracting me to wonder what sign I badly misread back at a forked road, I finally get that you're offering a remedy to how the rays would meet to combine as magenta (etc)? And your opposite directions fits the bill for making that happen. (If there are alternatives then the fysicks world needs to speak up about them clearly for a change instead of mumbling and waving hands in the background.)
Is that what that is -- his name on YouTube, or something else? At any rate, great work, ace investigator D__st_r ..... Er, SS -- at yanking the chain of The Great and Amazing Poradin and exposing his hopefully less than sinister aims and legerdemain, with a solution!
As for black lines... I've been taking everybody at their word that they're seeing black lines (in a different context than the absorption lines of spectroscopy).
Maybe it's analogous to Rorschach blots.
One person says: "I see Standing Buddha in that pattern."
I say: "Okay."
If several others also perceive Standing Buddha, then I'm even more okay with going along with it.
I mean, I'm the one who can't even see the colors that are supposed to be generated in both B&W animated and static optical illusions, so if there are black lines and/or lines that change with perspective, I'm game with it.
OMG! I just reread that old thread. How embarrassing. I was forum virgin. I’d never even spoke to a stranger online before. Yeah, I was bored as hell. Went back to work but I didn’t really need the money. So, I wanted to do something fun. I worked at a winery, but my girlfriend that I helped with her daughter’s wedding, she ended up buying that ranch. We’re doing events now.
As for the the black line, it’s the black separation line between the red and blue but it’s not due to the background being black. Like I said earlier, it even does it with the red and cyan.
There’s more to the story, though, C C, a lot more. He has a blog, a new one. At first, I thought he was just a crank and that I’d toss him a bone, but over the years, he’s posted a few good rebuttals. Unfortunately, it’s been a struggle for me to keep a lid on my sarcasm. Imagine that.
At one point, he exclaimed "Checkmate". I told him to print out the word, place the prism over the top, move his eye downward and watch his little "Checkmate" disappear. Total internal reflection; I thought it was funny and clever but whoo-wee…he was pissed.
His name is Remus and he lives in Australia. He used to resort to ad hominem attacks but he stopped doing that a few years ago. His modus operandi now is to ignore me until I grovel but there’s a slight chance that he could have been affected by the fires. I’ll hit him up again and invite him to join because it is his story after all. Who knows? Maybe he’ll change his mind. He’s stubborn, though.
I know the cause of the black line now and I’m fairly confident that I can prove and explain it ...with and without mathematics. If I’m wrong, I’d be the catch of the decade. Ha-ha, fish, as my son would say, but if I’m right, that would make him one hell of a storyteller (in a good way).
I have to finish moving my son. I’ll be returning on the 14th. I’ll show you some interesting photos when I return, and hopefully, I’ll hear from Mr. Poradin by then.
Dec 26, 2019 04:39 PM
(This post was last modified: Dec 26, 2019 04:40 PM by Secular Sanity.)
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