The Prism from Two Sides – The comparison of Newton’s and Goethe’s prism experiments with the aid of photographic tools
Essay

I. The comparison of Newton’s and Goethe’s prism experiments with the aid of photographic apparatus

From the perspective of optics, there are essentially two things worth doing with a prism: to pass light through it and study the spectrum, or to look through the prism directly and contemplate the world. In the “passing through”, awareness and striving to avoid completely incalculable chance resonate. Although the sun’s rays frequently refract and separate into colours before our very eyes, and everyone has already seen a rainbow, in order to experiment with the refracted rays of light, the conditions have to be established artificially, as, e.g., Newton did.
To look through the prism is a much more self-evident, natural thing: lifting the prism to the path of the gaze can even be an instinctive movement. Even if we do it intentionally, just as, e.g., Goethe did, still we take the direction of personal experience and subjective experimentation.
Since the inception of colour photography, countless photos have been made of Newton’s experimental position, of the rainbow as natural phenomenon, and of other manifestations of the refraction of light. But Goethe’s experiments performed with prisms have not been recorded, or at least I am not familiar with photos taken through a prism. One reason for this is most probably that an image seen-taken through a prism cannot be perfect, either in its sharpness, or in its preservation of straight lines. Contrary to this, the recording of a perspective similar to Newton’s is an accomplishable technical challenge.
If we set about taking photos through a prism, what appears in the pictures is that which we have seen with our own eyes looking through the prism: the edges of objects break down into bands of colour. Everything is precisely as Goethe observed in his own time, and as he noted meticulously. If we were to experience phenomena in our photos that stood in opposition to Goethe’s observations, certainly it would be worth repeating Goethe’s experiments systematically, and photographically, and by all means, it would be important to investigate what caused the deviations. But there is no difference. Why, then, did I make photos through a prism? In part, I produced a series of photos, apparent “illustrations”, so that I could immerse myself in Goethe’s theory by studying the phenomena visible in my own images. And on the other hand, so that I could lift the lonely work of subjective observation out of its own internal world, and thus, the experience could be shared.
I had two prisms made: one from synthetic resin, and the other from optical glass. Synthetic resin is not a pure material, and it refracts the light so much that even the view to the naked eye disintegrates. A ray of light going through a prism made from it produces such a strong distortion that the image becomes a practically unrecognisable tracing, though with rich associations. These photos begin to live a life of their own. Nevertheless, I found these photos much too complicated for accomplishing basic observations. The prism made from optical glass, however, gave a very precise image, albeit not approaching perfection; the pictures, both in their sharpness and in the preservation of straight lines, leave much to be desired. The imperfection, however, rather inspires than disturbs me. Furthermore, this entire concern of professionalism versus dilettantism, which in our case might come into play from the angle of the quality of photographability, would indicate an exciting analogy to the Newton-Goethe debate from my point of view. Many accused Goethe of dilettantism – who for nearly 40 years, steadfastly struggled against Newton’s theory in connection with colour – due to his simple, home-made experiments. To this day, the subjective evaluation of his experiences is a thorn in the side of the natural scientists. Newton, on the other hand, beyond the shadow of a doubt, was an ingenious scientist, whose discoveries and laws have determined our relationship to the world and our scientific way of seeing up to the present day. The photographic approach of the experiments meant for me the interesting “mapping” of the Newton-Goethe polemic, thoroughly processed and with an extensive literature behind it.
Interpreting the differences along their visuality, the debate could be enriched with a new, visual dimension. And this rendered it even more exciting.
In my essay, I briefly expound on the experiments of Newton and Goethe. Since many have done the same, first and foremost from a perspective of the history of science, I would rather focus on the aspects of the divergences that can be analysed through visuality. I interpret Goethe’s assertions with the aid of my own photographs. The conceptual experiments proceeding from the spectacle lead to the origins of colour wheels, and to representations of prisms, about which I will speak on the basis of their visual outward forms.

In 1672, Newton wrote a letter to the Royal Society, which contained all his revolutionary observations attained through light directed through the prism. The yet unknown mathematician came out publicly, and in his letter described results that stood in diametrical opposition to the accepted views of the era, according to which colours (including the colours of the spectrum) were created by light and darkness, and the modifying interaction of the two.
In the second part of his letter, Newton focused on the colours of the spectrum. His aim with his examination of the colours of the prism was to “reveal” the mathematical law hidden behind them, and to finally repudiate the previous ideas based on modifying effect. With his critical experiment, his experimentum crucis, he would refute them, at the same time verifying his own views.

According to these: “The colours then… are not the mutations deriving from the refraction or reflection of light submitted to natural bodies, but the original and inseparable properties of light, which differ ray by ray.”
The rays of light of differing fragility are each of different colour. “One of the rays can display the colour red and only the colour red…” “A certain degree of light refraction always appertains to the same colour and it is always the same measure of refraction that gives the same colour.” “Those rays which submit to the smallest degree of refraction all produce the colour red. …The greatest degree of refraction is submitted by the rays capable of producing the colour violet. …Such correlation between the colours and the degree of refraction prevails above strictly and precisely.”
Newton thus declares that white light inherently contains all colours, and he is able to prove this with his experiments, measurements and calculations. Although at the time of its introduction, his letter confronted a view that was accepted until then – at first, with little success – by the time Goethe appeared on the scene, his theory had spread among a wide circle and infiltrated into public thinking, becoming a truth carved in stone. It seemed that the problem had been resolved once and for all.
With his experiments with the prism, then, Goethe re-examined a phenomenon that had already been presumed explained for one hundred years. Nevertheless, he found Newton’s theory flawed in its foundations, and inadequate for the explanation of certain simple, everyday colour phenomena (e.g., afterimage, colour shadows, etc.). He was incensed at the thought that white light, as Newton contended, would be sufficient in itself for the creation of colours. He returned to the previous, traditional modificational principles, while in his methods, he considered his own subjective observations based on his own experience valid and leading to results. Taking these foundations as his point of departure, he produced his far-reaching work, Theory of Colours.

Goethe attempted to reconstruct Newton’s experiment, and with aim, borrowed a glass prism. He anticipated that looking into it, he would see a cavalcade of colours. Based on Newton’s assertions, he reckoned that any meeting of the prism and light at all would lead to a spectacular orgy of colour. On the contrary, he disappointedly concluded that, “we experience not even the most trifling play of colours. Examining pure monochromatic or black or white surfaces, in so far as the prism is clear, we can barely see them just a bit darker than with the naked eye; in any case, similarly, we will not perceive any sort of chromatism on them.” When he examined surfaces that were not homogeneous, but those in which significant shifts in light-intensity or contrast appeared – such as, e.g., a dark window frame before a light sky, or along the contours of furniture – it was only there that he saw colours. But even there it was not the entire spectrum that appeared, but only rather thin bands, comprising just one or two colours. The colourful edge appeared only between the light and dark border zones. From this, Goethe reached the conclusion that, “for the creation of colours, a boundary line is necessary”. This observation, which Goethe believed opposed Newton’s colour theory, inspired him to investigate the formation of colours with the refraction of light. He thought that colours proceeded with the union of light and dark, and were not constituents of light itself, as Newton postulated.
Perhaps it is thanks to Goethe’s first disappointment that he finally carried out investigations of an entirely different type than those of his “rival” 100 years prior. It is even more probable, however, that it came to him at just the right moment, since he found the way to criticise Newton, and moreover in such a way that meanwhile, he could formulate new assertions. A reconstruction of the original experiment could not be seriously considered, because his intention was to contradict Newton, and not to put his shoulder to Newton’s wheel with an experiment that would have substantiated his assertions.

Undoubtedly the most obvious way of examining the colours of a prism is if we simply look through the prism; however, we should not forget that Newton’s and Goethe’s experiments were very different. Not only in terms of their methodologies (Newton’s were objective, while Goethe’s were subjective), but also their results predictably addressed different things. Just as, for instance, we obtain entirely different experiences if we submit wine to a chemical analysis, as opposed to drinking it.
Naturally, Newton also looked through a prism, and performed such experiments, but what he saw may not have especially aroused his interest. It is conceivable that he was already too deep into the other type of experimentation, and he felt that a new kind of vision would distract him from advancing toward his appointed aim. It is possible that even if the interesting view caught his attention, he rather wanted to mathematicise his experiences, and to measure them, and for reasons of methodology he eliminated experiments of looking into from among the things to accomplish with a prism. It might have also been the case that he simply did not feel that what he saw was of interest. Moreover, we might even imagine that he did not even notice it, as in fact, he did not see the spectrum, since in certain cases, the register of colours seen through the prism almost corresponds to the colours of the spectrum. If we do not know what it is we see, or if we believe what we see to be something else, then we might even perceive divergent things as being identical. Prior knowledge and expectations influence perception with extraordinary power: these are capable of throwing light on viewpoints of an object that would otherwise remain invisible, or to the contrary, can leave in obscurity aspects that are clear and unequivocal to another viewer.

Only one who has her/himself performed the experiments can verify the accuracy of Goethe’s assertions. Moreover, it is not enough “only” to perform the experiments and observe the visible, and become immersed in the vision. More than that is required. In order to interpret the view, cerebral activity that is simultaneously external and internal, contemporaneously visceral and cognitive, is necessary. The experiences of sensory vision must be amalgamated with inner vision, with the expectations of imagination. Goethe called this “the exact faculty of imagination of the sensory organs”. All of this demonstrates and precedes that which the science of psychology believes today about perception: that it is actually the complicated reciprocal effect of the processes acting from below upwards (in the case of vision, retinal stimuli) and from above downwards (interpretation).

If we look through the prism, a diffused spectacle decomposed into colours appears before our eyes. If at the same time, we want to examine the creation of the colours, then we are undertaking a task similar to those doctors who wanted to relate as precisely as possible the effect of consciousness-altering drugs as practiced on themselves. The visual cortex resists the simultaneous perception of the two things; i.e., either we immerse ourselves in the vision, or we analyse the colours. We either perceive the perceptual experience, or what is represented by it. The fact that there is correspondence between the two is in vain, if in our experiment we precisely take apart the visible to its basic elements, just as in Gestalt psychology, the elements of vision are examined, unspun down to their simplest parts, which, as a whole still do not produce a vision of comprehension. I think that the expression, “the exact faculty of imagination of the sensory organs” refers to this irresolvable duality, or more precisely, offers egress from this duality.
Goethe commenced his experimentation with complicated things, but with time, he became convinced that every phenomenon could be traced back to a simple basic event, the colour manifestation that appeared at the meeting of a black and a white surface, which could be observed with the greatest intensity in this simple contrast. He produced cards with the simplest graphic elements. I even photographed a few of these cards, but for my study of the phenomena, it was not primarily, and not exclusively Goethe’s cards that I wanted to reproduce photographically, but I rather sought situations in my natural and material environment that are high-contrast in nature.
The medium of photography plays an interesting and fundamental role at this point. So long as I observed the view looking through the prism, it was truly difficult to both see the image and to analyse its basic components. As soon as the view is represented to us by a photograph, and we are no longer participants in the actual observation, the analysis and description become easier. Bridging the rift between complex, experiential perception and analytical, segmented observation – an accomplishment of mental leaps – becomes simpler if an image that is stable and external to us is available, which is not so volatile or changeable as direct observation, due to its two-dimensionality. The two-dimensional picture is a transitional state, which simultaneously alludes to and reminds of both positions, and thus, the perceptional shift is more rapid and comprehensible.

Let us see what sort of regularities can be discovered in the photographed view, experienced through the prism. Supplementing Goethe’s method, we will carry out the analysis of photographs alongside subjective experience.
Through the prism, we see the objects elsewhere, with multi-coloured, blurred contours, though the form and colour of most objects remains recognisable. As stated earlier, homogeneous surfaces retain their colour, and the colours appear only along the contrasts; for this reason, when looking through the prism, most often we will not see the colours of the rainbow, but only coloured border zones. These border zones are composed either of cool or warm colours, quite visibly of two colours each, which are quite easily distinguishable. These are red and yellow, or blue and cyan bands, which appear to be of identical thickness. The red and the blue always appear on the darker side of the contrast, while the cyan and the yellow always border the light surface.

In the case of dilation of border bands, or a change of direction in a high-contrast form, the outermost colours merge, and from their amalgamation, the colours green and magenta are created. My only experience opposed to that of Goethe is that for me, this phenomenon is more vividly descriptive in less geometric figures of more complicated tracing. In a picture in which the phenomenon is observable in its own complexity, it becomes more comprehensible just what border bands are, and their dilation and amalgamation. From photographs, it is easier to make the following observations on the mixed colours that are to be born as a function of the dilation of border bands.

It is observable on the thin object on the dark ground that between the colours of the two border bands, at the bottom of the image, where the object is a bit wider, i.e., the colour bands do not meet, we see white, while higher up, where the bands of yellow and cyan meet, green forms from the mingling of the two. Due to the changing width of the object, we can see the dilation of border bands in process, as well as its consequences.

In the other case, the dark, thin object on a light ground, where the colour-pairs of the border bands meet, there the two inner colours, i.e., the red and the blue mingle with each other, and magenta is created. The red and the blue slide into each other so much that we can no longer see anything of them: they completely extinguish each other, swallow each other, and converge in a magenta-hued band, in-between the two outer border band colours, the yellow and the cyan. Blue and red only appear there where the object widens, so that the dilation of the colour bands is also wider. In this case, observing the transitions and shifts in their progression is also illuminating.

II. The fruits of Newton’s and Goethe’s prism experiments, visual representations

We have seen that with Newton, to allow for the creation of colours, white light is sufficient, while according to Goethe’s thesis, the colours arise in the wake of the interplay of light and darkness. To illustrate their theories, they made drawings and diagrams, whose analysis offers a good surface for modulating from a visual point of view the diversity of their views, and for running through further experimentation with ideas.


Colour Wheels

Newton was the first to arrange into segments the colours of the spectrum. But why did he do it? The basis of his theory was the linearity of the spectrum, and the strict relationship between the breaches of various measure of the colours and the light rays. His colour wheel, which was nothing more than a spectrum connected at its two ends, was just like a knotted rope, but where the two ends meet at the knot, the continuity gives a jolt. The red and the violet wind up next to each other in the wheel like two strangers with nothing to do with each other; some sort of transition is palpably lacking between them. Most probably, Newton also saw the missing magenta colour when he combined the red and violet lights; for him, however, this new colour did not emerge as an absence. He distinguished between colours on the basis of the numerical values of refraction of light. The colour missing between the two endpoints of the spectrum has no independent spectral value. On the basis of the numerical value of the wavelength, there is truly no place for magenta in the series of identified colours. In so far as Newton was familiar with magenta, he might have thought of it as a sort of non-colour, as he believed that the spectrum “presents the complete series of colours.” Although he did not deal with the use of colour by artists or the mixing of pigments, with the arrangement of colours into a colour wheel, the possibility had been created for the study of colour correlations and relationships between them. Newton was also aware of the regularity of complementary colours in attaining white when combined together.
The segments of the colour wheel are not completely uniform. The five “original, or primary colours: red, yellow, green, blue and violet” are larger, while the two compound colours: orange and indigo are sections of smaller area. Newton did not consider it important to decide whether he saw 5 or 7 primary colours in the spectrum; I don’t know why he supplemented the 5 “original, or primary colours” with two from the “infinite series of intermediate colours”. All that is certain is that, according to the rules of analogy found in nature, he discovered correlations between the colours, as well as between the seven musical notes and the then known seven planets – so this may be why it became necessary for him to supplement the five primary colours with precisely two more.

In Goethe’s opinion, Newton’s colour wheel was far from complete. “…until now, the rainbow has been mistakenly comprehended as the example for the totality of colours – because the most important colour of all is missing from it,” namely, magenta.
In preparing his own colour wheel, it was not the linear spectrum that Goethe took into account, but rather continuous transitions that he strived to address.
We have seen that while looking through a prism, it is not the entire spectrum, but only two double colour-bands that appear. The colour-bands that appear on the light-dark boundary line are the blue-cyan and the yellow-red bands. These colours can be found at the two opposite sides of Goethe’s colour wheel (which are at the same time, the warm and cool opposing poles, too). Looking into the prism, when the colour-bands dilated more forcefully, he also observed their mixing. At the meeting of yellow and cyan colour-bands, green appears as the mixture of the two. When red and blue colour-bands meet, magenta is generated, and with this, the colour wheel is made complete.
In the interest of continuity of the transitions between the individual colours, Goethe supplemented his colour wheel to include 12 segments, in which the transitions between the already mentioned six colours also appear.

If we would like to produce the colour nuances missing from the spectrum, then we can only do it additively, i.e., through the additive mixing of lights. And Goethe truly constructed his entire system through the additive mixing of the previously mentioned 6 colours. On the other hand, when he had represented the colour wheel, he could only employ the subtractive method. But at the time from the moment that they wanted to reproduce exactly those colours, they came up against the difficulties of subtractive colour mixing, in the reproduction of colour that was less than with the additive method (today, the computer monitor and digital displays provide tools of an additive system that are accessible to everyone). But Goethe generated his colour wheel with the mixing of pigments not only out of necessity. He wanted to systematise the colours fundamentally for artistic use, with a wish to offer practical aid to painters, through the possibility to read a number of significant correlations on the harmony and contrast of colours, etc. With the subtractive method, pigment mixing, however, it is impossible to arrive at a precise result: magenta cannot be fabricated with colour mixing. Magenta paint, so long as it is not manufactured industrially, can only be imitated by mixing. Goethe, nevertheless, knew precisely the resembling colour to search for, and thus, he attained a result as close as possible to the colour wheels that are in use even today.
The segments of his colour wheels are of entirely uniform dimension. This is not surprising, as he thought in terms of conceptual pairs in a symmetrical-opposing relation, as based on polarity theory. Mechanically symmetrical representation renders it possible to read the opposites, contrasts and harmonies from the wheel.



Prism representations

Prism representations taking the Newtonian experiments as their basis concentrate on the division of the spectrum, and the refraction of light and the appearance of the colours of the spectrum occur within the beam of light. For the one who would like to become acquainted with and understand this experiment, it is only a question of external representation as to whether it is a real prism and a light passing through it, i.e., a real experimental situation, that s/he sees, or just a depiction of this, be it on film or through photography, or even in graphic form, perhaps as a completely reduced logo.

The objective experiment and its visual representation overlap. Vision itself, in part, is also a constructive, framing process. From the outset, only a visual extract of information fits into the visual field. When we pay attention to something, by way of the selection, we further narrow and sharpen the image falling into the visual field. Newton’s configuration directs attention to itself automatically, demarcating and framing. This is similar to a number of forms of visual representation, such as a photo, which appears as a section of reality contained within a frame, and which likewise can be viewed by more people at once than can the experiment itself. The Newtonian prism representation proved also to lend itself to becoming a symbol of science.

Goethe’s prism representation is of an entirely different nature. The illustrations show how colours originate at the light-dark juncture and in the course of mixing the colours of the border bands. The diagrams are as simple as possible: it is not possible to submit them to further abstraction without a loss of sense and meaning. And yet they seem rather complicated. First of all, there are two: one for the case of a dark object on a light ground, and the other for a light object on a dark ground. Goethe’s theory is clearly expounded, yet the representation is faulty. From this representation, it cannot be read that position depicted in them exists, in fact, only for the recipient who holds the prism exactly before her/his eye and looks directly through it. It moulds the view into a framing type of construction, which is in reality the result of an almost tactile personal experience. It presents something from the side view, turned inside-out, which, with lengthy work, already convinced us that it was visible only when viewed head-on. Here, abstraction does not mean the visual compression that the graphic designer executes when preparing a logo, but rather the unfolding of a spatial formula, a technical drawing of one of the three views: the delineation of the side-view. The side-view, however, means that it truly becomes commensurate with Newton’s prism representation. In this way, an interesting competition situation comes about, as if we should decide which representation is correct.

If we compare vision with perception through the other sensory organs, we find a significant disparity in the connection between the subject and the object. Touch, hearing, smell and taste are linked with a subjective relationship between the subject and object. In the case of touch and taste, direct physical contact is also necessary to obtain perceptive data. Contrary to this, vision requires physical distance between the subject and object. The separation of these may be the basis for the myth of objective vision, and the fact that what we see, we accept as truth.
With Goethe’s prism experiments, however, the physical distance between the subject and object is dissolved. Albeit it is not the prism itself that is the object under examination, nevertheless, we must lift it to our eye, and the closer we hold it to our eye, the better its modifying effect distends to the entire field of vision. The outsiderness of the observer is terminated, as s/he is immersed into the experience until the horizon.

The representation of Newton’s prism experiments is simple and clear because the position of the viewer is identical with that of the illustrator, and we observe the experiment from outside, from quasi-“side-view”. In such a configuration, we see just what they want to show us. Newton perceived the view (the spectrum), then defined what he saw. He showed us what we should see, and he also described in detail how we should interpret it.
As opposed to this, Goethe created the view that he observed, and then interpreted it. He did not consider the picture unfolding before him as a final outcome, but he rather wanted to persuade us to obtain our own experiences following from his guidance. He was interested in the nature of vision, and the process of perception.
His original intention was to counteract the Newtonian arguments, but with time, he fell into his own trap. He strived with incredible vehemence for his theories to be brought to an equal platform with Newton’s ideas, to be commensurate with them. He was successful in this, but was losing the battle for quite some time. Up till the present day, Goethe has remained a thorn in the side of the academic natural sciences. His scientific rehabilitation could only get underway with caution, first of all with the collaboration of scientific historians. And for this, an insight and acceptance are necessary of the fact that his approach springs from different roots than Newton’s, and this is why it is not even worth comparing them.
By now, as the foundations of cognitive psychology have been laid, it is easier to marvel that Goethe was, in fact, the harbinger of this modern science. Today, not only from philosophy, but also from the natural sciences (neurology), this viewpoint is familiar, which says that reality is a part of the observer – which is not a constant entity, but a product of the mind and the psyche. And that the constancy and order of the environment belong much more to the observer than to the thing that is observed.
From here it is just one more step for us to see not only the things by way of perception, but rather to render perception itself an object of examination.

Translated by Adele Eisenstein