The Newton disk, also known as the disappearing color disk, is a well-known physics experiment with a rotating disk with segments in different colors (usually Newton's primary colors: red, orange, yellow, green, blue, indigo, and violet, commonly known by the abbreviation ROYGBIV) appearing as white (or off-white or grey) when it's spun rapidly about its axis.
This type of mix of light stimuli is called temporal optical mixing, a version of additive-averaging mixing. [1] The concept that human visual perception cannot distinguish details of high-speed movements is popularly known as persistence of vision.
The disk is named after Isaac Newton. Although he published a circular diagram with segments for the primary colors that he had discovered (i.e. a color wheel), it is unlikely that he ever used a spinning disk to demonstrate the principles of light. He referred to the mixture of colors painted on a spinning top as "dirty" and described several experiments supporting his theory.
Transparent variations for magic lantern projection have been produced. [2]
Around 165 CE, Ptolemy described in his book Optics a rotating potter's wheel with different colors on it. He noted how the different colors of sectors mixed into one color and how dots appeared as circles when the wheel spun very fast. When lines are drawn across the disk's axis, the whole surface appears to be of a uniform color. "The visual impression that is created in the first revolution is invariably followed by repeated instances that subsequently produce an identical impression. This also happens in the case of shooting stars, whose light seems distended on account of their speed of motion, all according to the amount of perceptible distance it passes along with the sensible impression that arises in the visual faculty." [3] [4]
Porphyry (c. 243 – c. 305) wrote in his commentary on Ptolemy's Harmonics how the senses are not stable but confused and inaccurate. Certain intervals between repeated impressions are not detected. A white or black spot on a spinning cone (or top) appears as a circle of that color and a line on the top makes the whole surface appear in that color. "Because of the swiftness of the movement we receive the impression of the line on every part of the cone as the line moves." [5]
In the 11th century Ibn al-Haytham, who was familiar with Ptolemy's writings, described how colored lines on a spinning top could not be discerned as different colors but appeared as one new color composed of all of the colors of the lines. He deduced that sight needs some time to discern a color. al-Haytam also noted that the top appeared motionless when spun extremely quickly "for none of its points remains fixed in the same spot for any perceptible time". [6]
After Ibn al-Haytham, Fakhr al-Din al-Razi (d. 1209) performed the spinning disk experiment, and like his predecessors, he concluded that it showed an optical illusion. However, the astronomer-mathematician Nasir al-Din al-Tusi described al-Razi's text and arrived at a very different conclusion. Tusi introduced a common sense organ that forwards color impressions to the soul. When colors change too fast, this organ can only pass on the mixed colors. One of Tusi's students was Qutb al-Din al-Shirazi (d.1311), and together with his student Kamal al-Din al-Farisi, he tried to explain the colors perceived in the experiment. [7]
On 16 February 1672 (6 February 1671 [old style]), Newton sent a paper to the Royal Society's journal Philosophical Transactions, about the experiments he had been conducting since 1666 with the refraction of light through glass prisms. He concluded that the different refracted rays of light – well parted from others – could not be changed by further refraction, nor by reflection or other means, except through a mixture with other rays. He thus found the seven primary colors red, orange, yellow, green, blue, "a violet-purple" and indigo. When mixing the colored rays from a prism, he found that "the most surprising and wonderful composition was that of whiteness" requiring all the primary colors "mixed in a due proportion". [8]
In reaction to Robert Hooke's criticism of the new theory of light, Newton published a letter in the Philosophical Transactions, with other experiments that proved how sunlight existed of rays with differentcolorss. He described how the cogs or teeth of a gyrating wheel behind a prism can block part of the light so that all the colors would be projected successively if the wheel turns rather slow, but how all the colors will be mixed into white light if the wheel turns very fast. He also pointed out that rays of light that were reflected from multi-colored bodies were weakened by the loss of many rays and that a mixture of those rays would not produce a pure white, but a grey or "dirty" color. This could be seen in dust, which on close inspection would reveal that it consists of many colored particles, or when mixing several colors of paint. He also referred to a child's top which would display a "dirty" color if it was painted in several colors and made to spin fast by whipping it. [9]
After presenting his conclusions about dividing sunlight into primary colors and mixing them back together into white light, Newton presented a color circle to illustrate the relations between these colors in his book Opticks (1704). [10]
Many modern sources state that Isaac Newton himself used a spinning disk with colored sectors to demonstrate how white light was the compound of the primary colors. [11] [12] [13] However, these do not reference any historical source.
According to Joseph Plateau, the first to describe how a spinning disk with Newton's seven primary colors would show an (imperfect)white color was Pieter van Musschenbroek in 1762. [14]
Ḥasan Ibn al-Haytham was a medieval mathematician, astronomer, and physicist of the Islamic Golden Age from present-day Iraq. Referred to as "the father of modern optics", he made significant contributions to the principles of optics and visual perception in particular. His most influential work is titled Kitāb al-Manāẓir, written during 1011–1021, which survived in a Latin edition. The works of Alhazen were frequently cited during the scientific revolution by Isaac Newton, Johannes Kepler, Christiaan Huygens, and Galileo Galilei.
Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz. The visible band sits adjacent to the infrared and the ultraviolet, called collectively optical radiation.
Persistence of vision is the optical illusion that occurs when the visual perception of an object does not cease for some time after the rays of light proceeding from it have ceased to enter the eye. The illusion has also been described as "retinal persistence", "persistence of impressions", simply "persistence" and other variations. A very commonly given example of the phenomenon is the apparent fiery trail of a glowing coal or burning stick while it is whirled around in the dark.
The history of the telescope can be traced to before the invention of the earliest known telescope, which appeared in 1608 in the Netherlands, when a patent was submitted by Hans Lippershey, an eyeglass maker. Although Lippershey did not receive his patent, news of the invention soon spread across Europe. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo improved on this design the following year and applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens. By 1655, astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces.
Color theory, or more specifically traditional color theory, is the historical body of knowledge describing the behavior of colors, namely in color mixing, color contrast effects, color harmony, color schemes and color symbolism. Modern color theory is generally referred to as Color science. While there is no clear distinction in scope, traditional color theory tends to be more subjective and have artistic applications, while color science tends to be more objective and have functional applications, such as in chemistry, astronomy or color reproduction. Color theory dates back at least as far as Aristotle's treatise On Colors. A formalization of "color theory" began in the 18th century, initially within a partisan controversy over Isaac Newton's theory of color and the nature of primary colors. By the end of the 19th century, a schism had formed between traditional color theory and color science.
Opticks: or, A Treatise of the Reflexions, Refractions, Inflexions and Colours of Light is a collection of three books by Isaac Newton that was published in English in 1704. The treatise analyzes the fundamental nature of light by means of the refraction of light with prisms and lenses, the diffraction of light by closely spaced sheets of glass, and the behaviour of color mixtures with spectral lights or pigment powders. Opticks was Newton's second major work on physical science and it is considered one of the three major works on optics during the Scientific Revolution.
A color wheel or color circle is an abstract illustrative organization of color hues around a circle, which shows the relationships between primary colors, secondary colors, tertiary colors etc.
Kamal al-Din Hasan ibn Ali ibn Hasan al-Farisi or Abu Hasan Muhammad ibn Hasan ) was a Persian Muslim scientist. He made two major contributions to science, one on optics, the other on number theory. Farisi was a pupil of the astronomer and mathematician Qutb al-Din al-Shirazi, who in turn was a pupil of Nasir al-Din Tusi.
Theory of Colours is a book by Johann Wolfgang von Goethe about the poet's views on the nature of colours and how they are perceived by humans. It was published in German in 1810 and in English in 1840. The book contains detailed descriptions of phenomena such as coloured shadows, refraction, and chromatic aberration. The book is a successor to two short essays titled "Contributions to Optics".
Catoptrics deals with the phenomena of reflected light and image-forming optical systems using mirrors. A catoptric system is also called a catopter (catoptre).
Optics began with the development of lenses by the ancient Egyptians and Mesopotamians, followed by theories on light and vision developed by ancient Greek philosophers, and the development of geometrical optics in the Greco-Roman world. The word optics is derived from the Greek term τα ὀπτικά meaning 'appearance, look'. Optics was significantly reformed by the developments in the medieval Islamic world, such as the beginnings of physical and physiological optics, and then significantly advanced in early modern Europe, where diffractive optics began. These earlier studies on optics are now known as "classical optics". The term "modern optics" refers to areas of optical research that largely developed in the 20th century, such as wave optics and quantum optics.
In optics, the corpuscular theory of light states that light is made up of small discrete particles called "corpuscles" which travel in a straight line with a finite velocity and possess impetus. This notion was based on an alternate description of atomism of the time period.
A rainbow is an optical phenomenon caused by refraction, internal reflection and dispersion of light in water droplets resulting in a continuous spectrum of light appearing in the sky. The rainbow takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be caused by many forms of airborne water. These include not only rain, but also mist, spray, and airborne dew.
In optics, a dispersive prism is an optical prism that is used to disperse light, that is, to separate light into its spectral components. Different wavelengths (colors) of light will be deflected by the prism at different angles. This is a result of the prism material's index of refraction varying with wavelength (dispersion). Generally, longer wavelengths (red) undergo a smaller deviation than shorter wavelengths (blue). The dispersion of white light into colors by a prism led Sir Isaac Newton to conclude that white light consisted of a mixture of different colors.
The Book of Optics is a seven-volume treatise on optics and other fields of study composed by the medieval Arab scholar Ibn al-Haytham, known in the West as Alhazen or Alhacen.
On Vision and Colors is a treatise by Arthur Schopenhauer that was published in May 1816 when the author was 28 years old. Schopenhauer had extensive discussions with Johann Wolfgang von Goethe about the poet's Theory of Colours of 1810, in the months around the turn of the years 1813 and 1814, and initially shared Goethe's views. Their growing theoretical disagreements and Schopenhauer's criticisms made Goethe distance himself from his young collaborator. Although Schopenhauer considered his own theory superior, he would still continue to praise Goethe's work as an important introduction to his own.
The first reflecting telescope built by Sir Isaac Newton in 1668 is a landmark in the history of telescopes, being the first known successful reflecting telescope. It was the prototype for a design that later came to be called the Newtonian telescope. There were some early prototypes and also modern replicas of this design.
On Colors is a treatise attributed to Aristotle but sometimes ascribed to Theophrastus or Strato. The work outlines the theory that all colors are derived from mixtures of black and white. On colors had a pronounced impact on subsequent color theories and remained influential until Isaac Newton's experiments with light refraction.
Atmospheric optics is "the study of the optical characteristics of the atmosphere or products of atmospheric processes .... [including] temporal and spatial resolutions beyond those discernible with the naked eye". Meteorological optics is "that part of atmospheric optics concerned with the study of patterns observable with the naked eye". Nevertheless, the two terms are sometimes used interchangeably.
Quaestiones quaedam philosophicae is the name given to a set of notes that Isaac Newton kept for himself during his earlier years in Cambridge. They concern questions in the natural philosophy of the day that interested him. Apart from the light it throws on the formation of his own agenda for research, the major interest in these notes is the documentation of the unaided development of the scientific method in the mind of Newton, whereby every question is put to experimental test.