36.1 Nineteenth–Twenty-First Century
Color affects us in profound ways. Some of our feelings and reactions to the colors can be attributed to culture and society, while others originate from our psychological constitutions. The field known as color theory contains our current knowledge about colors, which is still largely theoretical in nature. Most of the content of the current color theory was developed in the nineteenth and twentieth centuries. Therefore, as the reader will note, this chapter covers the lion’s share of the contributions, discoveries, and inventions represented in this book. Physicists, in particular, examined various visual phenomena and greatly contributed to our understanding of the underlying reasons for their occurrence, which helped advance color science. Coverage of the history of color science would not be complete without mentioning contributions from many of the individuals who are introduced in the present chapter. The coverage, however, is by no means inclusive of everybody who made notable contributions. With sufficient public interest, future potential editions may remedy such shortcomings.
The period covered in this chapter includes pioneers who were born after 1800 and starts with the German Gustav Fechner who was interested in the mind-body problem. His studies included the discovery of perceived colors from slowly flickering black-and-white patters (known as Fechner color effect) and of color afterimages. In 1850, Fechner determined that the magnitude of a perception experienced is proportional to the logarithm of the stimulus intensity, now termed Fechner’s Law. This laid the grounds for modern psychophysics.
In the same period, Helmholtz established his trichromatic theory of color vision based on the works of Newton, Young, and his own extensive experimental data. He also established the first detailed quantitative data for the relationship between color stimuli and percepts. Based on logic alone, Grassmann in 1853 noted that Helmholtz’s then arguments regarding the existence of only two fundamental color vision processes in the eye were likely in error. He therefore proposed ideas of color mixture laws, which are currently considered fundamental components of a trichromatic theory of color vision.
Another important center of scientific discovery was in Great Britain where the polymath James Maxwell was advancing the field of optics and the study of color vision. Maxwell examined color mixing principles and demonstrated that white light could be the result of a mixture of red, green, and blue lights. He was instrumental in laying the foundations for practical color photography in 1861.
Physicists throughout the world, including the USA, were actively engaged in specifying color. In 1879, Ogden Rood described three colorimetric parameters, hue, purity, and brightness and estimated the number of discernible colored lights to be about 400 million. His Modern Chromatics book included a discussion of complementary colors and effects of contrast, influencing many artists including Seurat and Pissarro and likely contributed to the pointillism movement.
At the same time, in England, Lovibond was running a brewing company and was interested in finding a method to determine the color of his products. His solution, in what became the forerunner of the commercial colorimetry, was his invention of the Tintometer, a visual color-matching device which employed subtractive primaries of adjustable density (e.g., a series of cyan, magenta, yellow, and neutral glass filters) to match the colors of his liquids.
Back in Germany, Ewald Hering, in 1878, developed an alternative, opponent, and color vision theory postulating three opponent pairs of fundamental (unique) hues, yellow–blue, red–green, and white–black. This was first met with skepticism as it was at odds with the trichromatic theory proposed earlier by Helmholtz. A series of exchanges ensued between Hering and Helmholtz and Hering’s model received some support. It was some hundred years later when Hering’s model formed the basis of the Swedish Natural Color System atlas.
In the same time period, in Munich, von Bezold was studying lightning, color mixture, and binocular vision. In 1873, he showed that the apparent hue of a light stimulus changes due to variations in luminance or lightness of the stimulus, in what later became known as the Bezold–Brücke Effect. He also observed that the appearance of small stimuli is affected by changes in the color of surrounding stimuli, the so-called Bezold spreading effect. In the 1860s, the Czech physicist Ernst Mach had also noted that when viewing band regions of differing illumination or tone the brain exaggerates the difference between the regions that are touching, resulting in the light areas as appearing lighter and the dark areas as darker. This became known as the Mach band effect. In Britain, Abney, who was studying photography, had developed an emulsion to capture the far-infrared solar spectrum in 1887. One of his observations led to what is now called Abney’s Law, “a compounded stimulus’s luminance is linearly and additively related to the luminances of its components.” In 1909, he also discovered that perceived hue changes with increasing luminance of the stimuli, which became known as the Abney effect. These phenomena espoused the complexity of deciphering the visual experience.
Photography was also developing at a rapid pace and Jonas Lippmann, with no formal education beyond high school, developed a system of color photography in 1886 in France in what was certainly the first spectral imaging system. Lippmann’s work presaged modern photographic and holographic processes, and he received the 1908 Nobel Prize in Physics for this work.
The American mathematician and scientist, Christine Ladd-Franklin, who was among the first female graduate students at John Hopkins University, became interested in Helmholtz’s research when she investigated how points in space are dealt with by binocular vision. She had the opportunity to attend König’s lectures in Berlin. There, she developed an evolutionary theory of color vision, which was presented in 1892, involving three stages: the most primitive involving the black-and-white vision; the second stage adding yellow–blue, with the third adding red–green vision. This attracted considerable discussion in the following years.
Helmholtz trained a number of excellent students who continued to advance our understanding of the physiology of vision. These included Johannes von Kries, who was considered to be his greatest disciple. Von Kries proposed that individual components present in the organ of vision are completely independent of one another, and each is fatigued or adapted exclusively according to its own function, though he also recognized that this was likely too simplistic a view. His work became the foundation of chromatic adaptation models. Von Kries was also among the first proponents of the so-called zone theory of color vision that assumed trichromatic receptors (the cones) and opponent processing of the visual information, which was examined in greater detail in the following years. Another talented student of Helmholtz was Arthur König. An excellent physicist, König (together with C. Dieterici), in 1886, determined the spectral sensitivity functions of the three implied cone types and found that color normal individuals varied noticeably in their results. In 1892, he showed that dichromats only had two such functions. The data became known as the König fundamentals and were used for colorimetric calculations.
The technology of color printing owes a great deal to the work of Eugene Ives who, after leaving school at 12, became interested in the process. In 1875, he invented the halftone printing process for black-and-white photographs. Based on Maxwell’s trichromatic principles and through many additional inventions, in 1892, Ives obtained a patent for a trichromatic camera and later revolutionized color printing.
By the beginning of the twentieth century, activity pertaining to color order systems had once again become fervent. The American artist Albert Munsell felt that the best way to educating students about color was through a sound color order system. In 1900, he patented a balanced color sphere that, when spun rapidly, resulted in a gray appearance. Munsell coined the term Chroma to define a chromatic intensity scale and described a color order system in 1905 based on the three attributes value, chroma, and hue. The Atlas of the Munsell color system was published in 1907. In 1917, he formed the Munsell Color Company. Munsell’s system is perhaps the most important color atlas system yet developed. His efforts coincided with a similar body of activity by Wilhelm Ostwald, a Latvian of German descent, who was trained as a chemist and received the Nobel Prize for the discovery of chemical catalysis in 1909. He had considered color science to belong to the psychological domain. Nonetheless, he decided to develop a harmonious color order system, which he published in 1917/18. In 1918, he demonstrated the existence of metameric object colors and introduced the term metamerism. One of Ostwald’s students, Thomas Luther, was named assistant director and later a professor of physical chemistry at the Ostwald Institute at the University of Leipzig. However, Ostwald did not enjoy teaching and eventually resigned from his position and Luther was named director. This put him in a difficult position and thus he decided to move to the Technical University of Dresden where he launched his color research. He improved the chemistry of color photography. In 1927, Luther developed the secondary colorimetric functions for Hering’s four perceptually primary colors, yellow vs. blue and green vs. red, and trained a number of students, including Manfred Richter.
Meanwhile, the illumination industry was rapidly growing, and the need for lamps that accurately simulated various lighting conditions was becoming increasingly obvious in industrial and retail trade settings. The Canadian Norman Macbeth invented the illuminometer in 1915 to determine the spectral properties of light sources. He also developed and patented the use of high and low color temperature illuminants for testing metamerism. The question of how much light was necessary to provide adequate “seeing” had become relevant and important. The American Matthew Luckiesh developed many lamps including daylight simulating lamps while working at General Electric and examined the relations between lights and seeing. He noted how the level of illumination could have a physiological effect on people and recommended appropriate lights for different settings, including the White House in 1933, which gained him a reputation as “the father of the science of seeing.”
Scientific discoveries pertaining to the psychology of color perception were also evolving. The German physicist and psychologist David Katz examined the phenomenology of vision, including shape, structure, space, color, and movement, and defined three appearance modes of colors: film, surface, and volume. From 1907 to 1933, Katz and his students performed many experiments related to color appearance involving illumination changes, surround as well as light and dark adaptation to elucidate the role of external conditions on color vision. In 1923, the German Rudolf Kohlrausch investigated an observation by Helmholtz regarding the effect of hue on the perceived brightness of a stimulus. Kohlrausch observed that stimuli with luminance values identical to that of the achromatic surround often appear, to various degrees, lighter (more glowing) than the gray. This became known as the Helmholtz–Kohlrausch effect.
The need for an objective specification of color was increasingly felt in industrial and academic circles. Such specification, however, required the advent of accurate instrumentation to measure the spectral properties of the colored stimulus. Irwin Priest, who was working at the National Bureau of Standards in the USA, together with E. Lange, developed the Priest-Lange reflectometer in 1920 and invented a dispersion colorimetric photometer in 1924 for measuring light sources and an apparatus to measure dominant wavelength, purity, and brightness of color samples. This paved the way for further discoveries in the field.
The König fundamentals had provided a means of specifying color normal observers and with the advent of methodology to specify the spectral properties of light sources as well as the stimuli the ground was set to improve the mathematical definition of color. The Austrian physicist and Nobel laureate Erwin Schrödinger had become interested in color through the writings of the German philosopher Arthur Schopenhauer, who in turn was influenced by Goethe. Schrödinger used differential geometry to describe a color space and inferred the total color difference (in units of just-noticeable differences). In 1925, he also offered a mathematically detailed connection between the Young–Helmholtz trichromatic theory and Hering’s opponent-color theory.
The mathematical specification of the average normal observer, however, required additional experiments. In the late 1920s, two British scientists working independently, John Guild who worked at the National Physical Laboratory in England and David Wright, who was at the Imperial College, conducted a series of color-matching experiments for a total of 17 observers. This formed the basis of the international standard for measuring color, the CIE 1931 Standard Colorimetric Observer. Meanwhile, research by B. H. Crawford and W. S. Stiles in England in 1933 showed a reduction of brightness and the change of hue and saturation for stimuli entering the periphery of the iris compared to stimuli entering the center of the iris. This became known as the Stiles–Crawford effect.
From the 1920s to 1940s, the illumination industry was actively researching more efficient fluorescent lamps. Elliot Adams, at the General Electric Company, examined fluorescent and other gaseous discharge lamps, but he was also interested in the mathematical representation of the color. In 1942, he suggested two models “chromatic value” and “chromatic valence” for perceptually uniform color spaces. His models became the precursor of the modern CIELAB and CIELUV uniform color spaces. However, further observations showed that Adams Vy parameter did not sufficiently accurately represent a perceptually uniform lightness scale. American chemist, Isaac Godlove, in 1933, co-wrote an article on the neutral value scale which eventually resulted in the cube root version of the CIE L* lightness scale.
The specification of object color over this period was based on determination of CIEXYZ attributes. In 1923, Adams had advocated the use of opponent axes of red–green and yellow–blue which were considered to be easier to comprehend. Richard Hunter was a laboratory apprentice at the National Bureau of Standards under the energetic Chief Irwin Priest in 1927. There he designed a visual reflectometer. He later met with Deane Judd and was encouraged to build the first multipurpose reflectometer in 1938. Having conceived the “Lab” color scales in 1942, he designed and developed a number of instruments for the measurement of color and gloss. [In 1952, he formed, Hunter Associates Laboratory, Inc. (HunterLab), which is currently located in Virginia.]
In the same period, the American physicist Arthur Hardy was also pursuing the development of instrumental methods for measurement of color. In 1935, he filed a patent for the first recording spectrophotometer, which significantly contributed to the advancement of colorimetry in the following years.
With mass productions, the industrial reproduction of color required accurate predictive models of color admixture. Paul Kubelka, born in Czechoslovakia to Austrian parents, with Franz Munk, published a theory of light absorption and scattering by a layer of paint, in 1931, which became known as the Kubelka–Munk theory. In the following years and with the advent of computer technology, this model became the leading theory for colorant formulation. Several mathematicians examined, refined, and corrected the available mathematical models of the color of the time. The American physicist Deane Judd wrestled throughout his career with the relationship between color stimuli and color perception. This was an important period in the activities of the International Commission on Illumination (CIE). Judd developed a polynomial function to describe the relationship between Munsell value and luminance factor, which while accurate, was considered cumbersome and was not adopted. He conducted a large number of additional studies, some of which became the basis for the CIE u,v color diagram in 1960.
Industrial quality control of products necessitated the development of defined light sources for visual assessment. The Munsell color system had also become the most widely used system for the specification of the color of products. The American Dorothy Nickerson studied and improved the Munsell system and its definition in the CIE colorimetric system. In 1936, Nickerson published the first color difference formula for industrial use, based on the addition of increments of Munsell hue, chroma, and lightness scale values.
Another domain where the color science front was advancing was the neurophysiological examination of color perception. In Britain, William Rushton laid the groundwork for the establishment of the modern theory of nervous excitation and propagation in 1935 and developed the principle of univariance. He noted, “the output of a receptor depends upon its quantum catch, but not upon which quanta are caught.” Several of the laws of color mixing are a direct consequence of this principle.
During the Second World War, vision research focused on night vision, camouflage, aerial and flicker vision, among other things. In America, Arthur Hardy who was chair of Massachusetts Institute of Technology’s physics department created the Visibility Laboratory with Seibert Duntley in 1939. He applied optics to such problems as camouflage, misdirection of aerial bombardment, target location, and visibility of submerged objects at sea. Meanwhile, the Deutsches Institut für Normung (DIN, German institute for industrial standards) had decided to develop a national standard color system and atlas. Manfred Richter was asked to take charge of this activity in 1941. Taking the Ostwald system as reference the resultant perceptually uniform DIN6164 space contained hue, saturation, and darkness as its three attributes and became the German industrial standard system.
In England, the temporary blinding effects of gunfire flashes during the war inspired B. H. Crawford to study vision under such conditions. “Crawford Masking” as it became known, referred to perception of a bright stimulus prior to a later less bright stimulus. Crawford also determined the average spectral response of the human eye under low levels, scotopic, and illumination conditions. This led to the international standard for spectral luminous efficiency for scotopic vision (the V’(λ) function). In America, Edwin Land’s company was commissioned to develop new kinds of night vision goggles and a system that could reveal enemies in camouflage uniforms. In the years after the War, Land continued to cooperate with the US government and was involved in the development of the U2 spy plane.
Meanwhile, Ralph Evans, who was leading color quality research at Eastman Kodak’s Color Technology Division, was convinced that a better understanding of color perception would result in improved color photography and printing. Leo Hurvich and Dorothea Jameson conducted research on distance perception at Harvard University and were among those that joined Kodak in 1947. Evans was interested in the appearance of color stimuli under specific conditions. He concluded that certain test colored stimuli exhibit a grayish appearance against a white surround of a certain luminance that diminishes steadily as its luminance increases, up to a point where the apparent grayness disappears and eventually the test appears fluorent. He developed the G0 function that showed zero-grayness to vary across the spectrum as a function of dominant wavelength and used the term ‘brilliance’ to describe this perceptual parameter. He concluded that chromatic stimuli have five independent variables: hue, saturation, lightness, brilliance, and brightness. The work indicated the complexity of color appearance. Dorothea Jameson and Leo Hurvich married in 1948 and continued to investigate the perceptual aspects of hue, saturation, and brightness of colors in an academic setting. They supported the opponent-color vision theory. Using hue cancellation method, they identified the locations of unique hue stimuli as approximately 475 nm for blue, 500 nm for green, 580 nm for yellow, with red located near the high end of the spectrum. However, it has since become evident that the human visual system has a more complex neurological basis.
Meanwhile, the US government and several industrial sectors had become interested in determining the relationship between color and its psychological effect on safety, employee morale, productivity and sales in the 1940s. The American Faber Birren, who came from an artistic background, examined the relationship between color, perception, and emotions. His recommendations included the functional use of color, especially in hospitals and schools such as changing wall and interior colors to reduce visual fatigue and using bright colors on machinery to reduce accidents. These recommendations were adopted by the Occupational Safety and Health Administration and are still in use today.
In the mid-1940s David MacAdam, who was trained under Hardy at MIT, established Hardy’s reflectance spectrophotometer as a reliable industrial measuring instrument and invented a tristimulus integrator as an accessory. In 1942 and assuming that the basis of color difference perception was the statistical error in matching the appearance of a given color stimulus, he conducted an extensive experiment with one observer, the result of which was expressed in the CIE chromaticity diagram in the form of statistically derived ellipses.
In the field of psychology, the German Gestalt movement was gaining momentum in the USA. The American Harry Helson, who was a proponent of the approach, examined visual perception and postulated his adaptation-level theory in 1947. He noted that an individual’s basis of judgment of a stimulus is based on their prior subjective experiences as well as their recollections of how they perceived similar stimuli in the past and in different situations. This view was debated in the following years.
A mathematical description of color stimuli that occupied a field of view larger than 2º necessitated a re-examination of the color-matching functions of observers. The Englishman Stanley Stiles, in the late 1950s, spent much time and effort in constructing a visual colorimeter to redetermine the color-matching functions of the normal observer. This provided the major basis for what became the CIE 1964 supplementary standard colorimetric observer for a field size of 10º.
In the meantime, Land at the behest of his three-year-old daughter had developed the Polaroid instant camera in 1947. He conducted a series of color reproduction experiments with projectors and in 1959 concluded, “The rays are not in themselves color-making. Rather they are bearers of information that the eye uses to assign appropriate colors to various objects in an image.” In 1964, Land proposed the “retinex” (derived from retina and cortex) model, a mathematical model to predict the influence of surrounding color fields on the appearance of a test field which in the following years received some criticism from other researchers.
The psychology of color perception was further advanced with the findings of Stanley Stevens who examined brightness perception as a function of adaptation. In a publication in 1961, Stevens summarized psychophysical scaling data for perceptual stimuli and illustrated that all perceptual data could not possibly follow the logarithmic relationship as predicted by Fechner. Stevens proposed power functions with various exponents depending on the perception being scaled. This is now known as the Stevens Power Law. In an intriguing experiment, Stevens also demonstrated that as the level of lighting increases, dark colors look darker and light colors appear lighter. This is known as the Stevens Effect and was used in mathematically modeling color appearance.
The need to facilitate the formulation of colorants to match a given stimulus resulted in a collaboration between H. R. Davidson and H. Hemmendinger in America. Around 1954, Hugh Davidson developed the first automatic tristimulus integrator and attached it to the GE-Hardy spectrophotometer. This provided a quick way of obtaining tristimulus values. In 1958, Henry Hemmendinger, together with Davidson, developed Colorant Mixture Computer (COMIC). This was an analog computer for matching reflectance functions of dyed or painted samples with related colorants. This technology replaced centuries-old color matching by trial and error. They also quantified performance errors in colorimetry, incurred by photometric equipment and by human observers and examined the breakdown in a color match incurred by changing either the illuminant or the observer. The process was significantly enhanced when Eugene Allen developed a set of basic mathematical equations for color matching, using matrix algebra and the Kubelka–Munk equations in 1966. The methodology became an important basis for the widespread industrial use of digitally based computer colorant formulation. Allen proposed matching algorithms for both one- and two-constant Kubelka–Munk data, the former for dyes and the latter for pigments.
Over this period Gunter Wyszecki introduced the mathematical concept of “metameric blacks,” psychophysical definitions of blacks with tristimulus values 0, 0, 0 that, within limits, can be added to a spectral reflectance to form the various possible metamers having an identical set of tristimulus values under a given light in 1958. With Stanley Stiles, he developed mathematical methods to calculate the number of possible metamers for given chromaticities.
After Macbeth Sr. passed away, his son Norman Macbeth Jr. took over the affairs of the Macbeth Company, which merged with Kollmorgen Corp. in the mid-1960s. In 1967, Macbeth Jr. invited Bartleson to join Macbeth Corporation. In the same year, Bartleson with Ed Breneman on the effect of light and dark surrounds on apparent contrast, which later became known as the Bartleson–Breneman effect. Among the products developed by GretagMacbeth Company was the Macbeth ColorChecker Color Rendition Chart, by McCamy, Marcus, and Davidson in 1976.
Calvin McCamy also invented an annular illuminator that would ensure azimuthally uniform illumination in a 45/0 spectrophotometer which made measurements more reproducible. Meanwhile, in 1970, Ralph Stanziola co-founded Applied Color Systems, Inc. (later Datacolor) and developed the first colorant-dispenser system driven by computer color matching in 1979 and patented a Maxwell-disk-based color simulator in 1980.
During this time, a need for academic and industrial training in color technology had become evident. Rensselaer Polytechnic Institute established a new research laboratory to run the undergraduate and graduate program in color science. Fred W. Billmeyer and Max Saltzman co-authored a popular textbook, Principles of Color Technology, which went through two editions during this period (1966 and 1981). Fred Billmeyer also initiated the journal Color Research and Application and was the founding editor until 1986.
Meanwhile, the American psychologist Jozef Cohen had gotten involved in the psychophysics of color between 1946 and 1949 and, after an intermission, again later in the mid-late 1960s. In the 1980s, together with W. E. Kappauf, he examined a concept that he named fundamental color metamers. Using principal component analysis, he decomposed a reflectance or a spectral power function into two components: the fundamental function and a metameric black function, a concept that was introduced by G. Wyszecki in 1953. Cohen named the resulting space the fundamental color space. It gained wider traction after publication in 1988, and his findings provided much new insight into the nature of color stimuli.
The neurophysiological processes involved in color vision were continued to be examined during this period. In 1972, Boynton, together with his colleague D. I. A. MacLeod, proposed a Luther-inspired chromaticity diagram based on normalized cone response functions. This psychophysical colorimetric system was widely used in scientific efforts.
Japan had also become an important center of color research after the Second World War. Indow Tarow had a fascination with the mathematics of psychological findings. He examined the implicit global structures of the visual space relating to its geometry, taking into account the various conditions of viewing, surround and illumination. He also examined the Munsell space using the method of multidimensional scaling in 1988. Meanwhile, Yoshinobu Nayatani was interested in color vision and modeled chromatic adaptation, color appearance, and observer metamerism. For Nayatani, gray had a special role as a central color in the opponent-color order system. He discussed how the two opponent axes change from red–green to red–gray and gray–green and from yellow–blue to yellow–gray, and gray–blue. Several other scientists in Japan have examined and advanced the psychology of color perception, color imaging, and color reproduction techniques.
Further advances in establishing relationships between neurobiological activities related to vision in the brain and the corresponding visual experiences in consciousness continued with the works of David Hubel and Torsten Wiesel in America. Hubel and Wiesel’s electrophysiological measurements of signals in cells of the lateral geniculate nucleus of cats earned them the Nobel Prize in medicine or physiology in 1981. This pioneering work enabled an entirely new path of research concerning the neurobiology of the mammalian visual system. In the USA, the De Valois’ were also interested in the question of the representation of spatial vision in the brain. In 1993, Russell and Karen De Valois developed a multistage color vision model and realized that the responses of opponent-color cells in the lateral geniculate nuclei were not in agreement with implicit perceptual performance and developed a more complicated four-stage model in general agreement with then current neurophysiological findings. More than 20 years later, it appears that the activities in the brain related to color perception are even more complex than assumed and a broadly supported model is yet to be developed.
The history of advances in the study of color from an artistic perspective requires a separate volume but it is important to include some of the key individuals in the twentieth century who had a significant impact in the field. The Swiss Johannes Itten and the German Josef Albers were influential artists and educators in this period. Itten largely excluded scientific developments from the mid-nineteenth century onwards and supported the idea of subjective harmony while regarding color expression as involving objective rules. He presented a dictionary of color and color combinations in which complementary colors were expected to have opposite meanings, secondary colors were expected to combine the meanings of the primaries they “contained,” and meanings could be modified by contrast effects with surrounding colors. Josef Albers, on the other hand, was interested in the perception of color as conditioned by changing light, shape, and placement and spent many years examining the topic. His “Homage to the Square” attracted praise and criticism. In his Interaction of Color book, published in 1963, he stated, “every perception of color is an illusion … we do not see colors as they really are. In our perception they alter one another.” These general claims about the color experience and the system of perceptual education had wide traction in the artistic community but may have been somewhat misleading, likely due to a misconception of the aesthetic appreciation of color, simultaneous contrast, and the underlying psychological effects.
Due to the multi-disciplinary nature of color science domain, there are likely several individuals, with important and significant contributions to the field, who have not been included in this volume. Nonetheless, the hope was to include as many of the leading pioneers as possible to provide the reader with a historical perspective of advances in this field. Many of these pioneers spent their lifetimes in the pursuit of their discoveries. In the busy and overwhelming information technology age, it is easy to forget that behind each discovery and invention lies a heap of trials and tribulations, with all the glories and despairs over a journey that we call life.
We stand on the shoulders of giants…