What is the dispersion of light in physics. Dispersion of light

Encyclopedia plants 20.09.2019

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The world filled with millions of diverse shades. Thanks to the properties of light, each object and the object around us has a certain color perceived human vision. The study of light waves and their characteristics allowed people to look deeper on the nature of light and phenomena associated with it. Today we will talk about dispersion.

Nature of Light

From a physical point of view, the light is a combination electromagnetic waves from different values Length and frequencies. The person's eye perceives not any light, but only one, whose wavelength length ranges from 380 to 760 nm. The remaining varieties remain invisible for us. These, for example, include infrared and ultraviolet radiation. The famous scientist Isaac Newton represented the light as a directional flow of the most small particles. And only later it was proved that he is by its nature is a wave. However, Newton was still partly right. The fact is that light has not only wave, but also by corpuscular properties. This is confirmed by all famous phenomenon Photo effect. It turns out that the light stream has a two-way nature.

Color spectrum

White light, accessible to human vision, is a combination of several waves, any of which is characterized by a certain frequency and its own photon energy. In accordance with this, it can be decomposed on the waves different color. Each of them is called monochromatic, and a specific color corresponds to its range of length, frequency of waves and photon energy. In other words, the energy emitted by the substance (or absorbed) is distributed through the above indicators. This explains the existence of a light spectrum. For example, the green spectrum color corresponds to the frequency located in the range from 530 to 600 THz, and purple - from 680 to 790 THz.

Each of us has ever seen the rays on faceted products from glass or, for example, on diamonds. It is possible to observe this by such a phenomenon as a dispersion of light. This effect reflecting the dependence of the refractive index of the object (substance, medium) from the length (frequency) of the light wave, which passes through this subject. The consequence of such a dependence is the decomposition of the ray on the color spectrum, for example, when passing through the prism. The dispersion of light is expressed by the following equality:

where n is the refractive index, ƛ - frequency, and ƒ - the wavelength. The refractive index increases with increasing frequency and reducing the wavelength. Dispersion We are often observed in nature. Its most beautiful manifestation is a rainbow, which is formed due to the dissipation of sunlight when passing them through numerous raindrops.

First steps on the way to open dispersion

As mentioned above, the light stream when passing through the prism decomposes on the color spectrum, which Isaac Newton studied quite in detail in due time. The result of its research was the opening of the dispersion phenomenon in 1672. Scientific interest in the properties of light appeared before our era. The famous Aristotle has already noticed that sunlight can have different shades. The scientist argued that the nature of the color depends on the "amount of darkness" present in white light. If it is a lot, then there is purple, and if not enough, then red. The Great Thinker also said that the main color of the light rays is white.

Studies of Newton's predecessors

Aristotelian theory of interaction of darkness and light did not refuted the scientists of the 16th and 17th centuries. And the Czech researcher Marzi, and the English physicist Chariot independently carried out experiments with Prism and were firmly confident that the reason for the appearance of different shades of the spectrum is precisely mixing the light flow with darkness when it passes through the prism. At first glance, the findings of scientists could be called logical. But their experiments were sufficiently superficial, and they could not reinforce them with additional studies. So it was for the case not to take Isaac Newton.

Opening Newton

Thanks to the deliberate mind of this outstanding scientist, it was proved that the white light is not the main one, and that the remaining colors arise at all as a result of the interaction of light and darkness in different ratios. Newton denied these beliefs and showed that white light is composite in its structure, it is formed by all the colors of the light spectrum, called monochromatic. As a result of the passage of the light beam through the prism, the variety of colors is formed due to the decomposition of white light into the components of its wave flows. Such waves S. different frequency And the length is refracted in the medium in different ways, forming a certain color. Newton put experiments that are still used in physics. For example, experiments with crossed prism, using two prisms and mirrors, as well as light transmission through prism and perforated screen. Now we know that the decomposition of light on the color spectrum occurs due to different speeds of the wave different length and frequency through a transparent substance. As a result, some waves come out of the prism earlier, others - a little later, the third - even later and so on. So the light flow decomposition occurs.

Anomalous dispersion

In the future, scientists of the physicists of the year before lasting the next discovery relating to the dispersion. The Frenchman Lero discovered that in some media (in particular, in iodine pairs), the dependence expresses the dispersion phenomenon is violated. For the study of this issue, the physicist Kundt lived in Germany. For his research, he borrowed one of Newton's methods, namely, experience using two crossed prisms. The difference consisted only that instead of one of them, Kundt used a prismatic vessel with a solution of cyanine. It turned out that the refractive index during the passage of light through such prisms is increasing, and does not decrease, as happened in Newton's experiments with conventional prisms. The German scientist found out that this paradox is observed due to such a phenomenon as the absorption of light substance. In the described experiment, the Kunda absorbing medium performed a solution of cyanine, and the dispersion of light for such cases was named abnormal. IN modern physics Such a term is practically not used. To date, Newton's open Newton and later, anomalous dispersion is considered as two phenomena belonging to one teaching and having a common nature.

Low-dispersed lenses

In photographic engineering, the dispersion of light is considered an undesirable phenomenon. It becomes the cause of the so-called chromatic aberration, in which the colors appear on the images. Shades of photos do not correspond to the shades of the object being removed. Especially unpleasant such an effect becomes for professionals photographers. Due to the dispersion on the photographs, there are not only distortion of colors, but also there is often blur of the edges or, on the contrary, the appearance of the too defined border. World manufacturers of photographic equipment cope with the consequences of such an optical phenomenon with the help of specially developed low-dispersed lenses. The glass, from which they are produced, has an excellent property equally refracting the waves with different lengths of length and frequency. Lens in which low-dispersed lenses are installed are called coarse.

Tasks lesson:

Educational:
- introduce the concepts of the spectrum, the dispersion of light;
- acquaint students with the history of the opening of this phenomenon.
- visually demonstrate the process decomposition of a narrow light beam into components of various color shades.
- to identify the differences in these elements of the beam of light.
- continue the formation of scientific worldview of students.
Developing:
- development of attention, shaped and logical thinking, memory when studying this topic.
- stimulating the cognitive motivation of students.
- development critical thinking.
Educational:
- upbringing interest in the subject;
- educating the feelings of the beautiful, beauty of the surrounding world.

Type of lesson:lesson studying and primary consolidation of new knowledge.

Teaching methods:conversation, story, explanation, experiment. (Information-developing)

Requirements to basic level Preparation:be able to describe and explain the dispersion phenomenon.

Equipment and materials:computer, Color Cards, Flat-Photo Parallel Plates

Lesson plan:

	Stages lesson	Time, Min.	Takes and methods
1.	Coloring	5 min. (Before the lesson, on change)	Select a color card that matches the mood, each students before a lesson on change.
2.	Motivation	2 minutes.	Teacher's story
3.	Orgmoment	3 min.	Reading verse student
4.	Studying a new material	19 min.	Teacher's story. Demonstration of experiments. Conversation on issues. Records in notebooks.
5.	Fixing Sincweight	12 min.	Consultation teacher. Observation. Student responses. Compilation of synkievine
6.	Summarizing. Coloring	3 min.	Generalization of the material studied. Collective Card Selection, Mood, Each Students at the end of the lesson
7.	Homework	1 min.	Recording on the board. Teacher's comment.

Before the start of the lesson, to change the diagnostics of the class "Class". Each student, entering the class, chooses a card with a certain color corresponding to his mood, a chart "Class" color in the beginning of the lesson is compiled.

Yellow color - good
Orange - very good
Red - joyful
Green - calm
Blue - sad
Brown - anxious
Black - bad
White - indifferent

Epigraph to the lesson:

In nature, it is impossible to be cluttered with a sloppy and half-way, it is always beautiful.

R. Emerson (American philosopher XIX century)

DURING THE CLASSES

1. Motivation

Sunlight has always been and remains for a person a symbol of joy, eternal youth, all the best, best that could be in life:

"Let always be the sun.
Let always be the sky ... ", -

Such words are in the famous song by the author of the words - Lev Oshanin.
Even a physicist. Accustomed to deal with facts, with accurate registration of phenomena, sometimes experienced a sense of awkwardness, saying that the light is electromagnetic waves of a certain wavelength and nothing more.
The length of the light wave is very small. Imagine middle sea wavewhich would increase so much that it took one entire Atlantic Ocean - from America to Lisbon in Europe. The length of the light wave with the same increasing only slightly exceeded the width of the book page.
Question:
- Where do these electromagnetic waves come from?
Answer:
- The source of them is the sun.
Together with visible radiation, the Sun sends us thermal radiation, infrared and ultraviolet. The high temperature of the Sun is the main reason for the birth of these electromagnetic waves.

2. Orgmoment

Formulation of the theme and lesson purposes.

The theme of our lesson is "dispersion of light." Today we need:

Introduce the concept of "spectrum", "Light dispersion";
Identify the features of this phenomenon - dispersion of light;
Get acquainted with the history of the opening of this phenomenon.

Activation of mental activity:

The student reads a poem

Sun fragrance

Sun odor? What kind of nonsense!
No, not nonsense.
In the sun sounds and dreams,
Fragrances and flowers,
Everyone merged into conscious choir,
All spurled into one pattern.
The sun smells herbs,
Fresh Kupavami
Awakening in spring
And Smolito pine,
Sleeperless lights
Landlocks drunk
What is victory blooming
In the acute smell of land.
The sun shines with the stons
Leaves green,
Breathe outwardly birds of birds
Breathes with laughter of young people.
So Molvi to all the blinders:
Will you!
Don't see the paradise gates to you
There is a fragrance in the sun,
Sweet only to us
Visible birds and flowers!
A. Balmont

3. Studying a new material

A bit of history

Speaking about these ideas, you should start with the theory of Aristotle colors (IV century BC). Aristotle argued that the difference in color is determined by the difference in the amount of darkness, "mixed" to the solar (white) light. Purple color, according to Aristotle, occurs with the greatest addition of darkness to the light, and the red - with the smallest. Thus, the colors of the rainbow are complex colors, and the main light is the main. Interestingly, the appearance of glass prisms and the first experiments on the observation of light decomposition by prisms did not give rise to doubts in the correctness of the aristotleous theory of colors. And Chariot, and Marzi remained followers of this theory. This should not be surprised, since at first glance the decomposition of light with prisms on different colors seemingly confirmed the ideas about the occurrence of color as a result of mixing light and darkness. The rainbow strip occurs just on the transition from the shadow strip to the illuminated, that is, on the boundary of the dark and white light. From the fact that the purple beam passes inside the prism is the greatest path compared to other color rays, it is not possible to conclude that the purple color occurs with the greatest loss of its white light when passing through the prism. In other words, the greatest damping of darkness to the white light occurs on the greatest path. The falsity of such conclusions was not difficult to prove, putting appropriate experiments with the same prisms. However, no one did before Newton.

Sunlight has a lot of secrets. One of them - dispersion phenomenon. The first of him discovered the Great English Physic Isaac Newton in 1666By improving the telescope.

Dispersion of light (Light decomposition) is a phenomenon due to addiction absolute indicator The refraction of the substance from the frequency (or wavelength) of the light (frequency dispersion), or, the same, the dependence of the phase rate of light in the substance from the wavelength (or frequency).

Experimentally dispersion of light was opened by I. Newton around 1672, although theoretically quite well explained significantly later.
One of the most visual examples Dispersions - decomposition of white light when it passes through the prism (Newton's experience). The essence of the dispersion phenomenon is the unequal speed of the spread of the light beams with different wavelengths in the transparent substance - the optical medium (while in vacuo the speed of light is always the same, regardless of the wavelength and therefore color). Usually, the greater the frequency of the wave, the greater the refractive index of the medium and the less of its speed of light in it:

red color is the maximum speed in the medium and the minimum degree of refraction,
purple color has a minimum light speed in the medium and the maximum degree of refraction.

The dispersion of light allowed for the first time it is quite convincingly to show the composite nature of white light.

White light decomposes on the spectrum and as a result of passing through the diffraction grid or reflection from it (this is not associated with the dispersion phenomenon, but is explained by nature diffraction).

Diffraction and prismatic spectra are somewhat different: the prismatic spectrum is compressed in the red part and stretched in purple, and is located in descending order of the wavelength: from red to purple; Normal (diffraction) spectrum is uniform in all areas and is located in ascending order of wavelengths: from violet to red.

Knowing that the white light has a complex structure, you can explain the amazing variety of paints in nature. If the subject, such as a sheet of paper, reflects all the rays falling on it of various colors, then it will seem white. Covering paper with a layer of red paint, we do not create the light of a new color, but we delay some part of the existing one on the sheet. Only red rays will be recorded now, the rest will absorb the layer of paint. The grass and the leaves of the trees seem to us green because of all the sunny rays falling on them they reflect only the green, absorbing the rest. If you look at the grass through the red glass, passing only the red rays, it will seem almost black.

The dispersion phenomenon opened by Newton is the first step towards understanding the nature of the color. The depth of understanding of the dispersion came after the color dependence on the frequency (or length) of the light wave was found.

Thomas Jung (1773-1829) in 1802 the first measured wavelengths of different colors.

After discovering the light dispersion, the main value that determines the color of the light has become the wavelength. Main color receiver - retina eye.

Color- There is a feeling that occurs in the mesh shell of the eye when it is excited by the light wave of a certain length. Knowing the wavelength of the emitted light and the conditions for its distribution, you can defier with a high degree of accuracy to say which color will see the eye.

It may be that the retina's retina does not perceive one of the main colors or does not respond completely to it, then this person has a violating color. Such a lack of vision is called daltonism.

A good color is very important for a number of professions: sailors, pilots, railway workers, surgeons, artists. Created special devices - anomaloscopesto study violations of color vision.

The dispersion explains the fact of the appearance of the rainbow after the rain (more precisely the fact that the rainbow is multicolored, and not white).
First attempt to explain radugu As a natural phenomenon of nature was made in 1611 by Archbishop Antonio Dominis.

1637 year - The scientific explanation of the rainbow for the first time gave René Descartes. He explained Rainbow on the basis of refraction laws and reflection sunlight in drops of rain. The dispersion phenomenon has not yet been open, therefore the Rainbow of Descartes was white.

30 years later Isaac Newton complemented the theory of Descartes, explained how color rays were refracted in drops of rain.

"Decartes hung a rainbow in the right place in the sky, and Newton has bloomed it with all the colt paints"

American scientist A. Frazer

Rainbow - This is an optical phenomenon associated with the refraction of light rays on numerous rain droplets. However, not everyone knows how it is the refraction of light on the droplets of rain leads to the occurrence of a giant multicolor arc on the sky. Therefore, it is useful to dwell on the physical explanation of this spectacular optical phenomenon.

Rainbow eyes attentive observer. First of all, the rainbow can only be observed aside, opposite to the sun. If you get face to the rainbow, then the sun will be rear. Rainbow occurs when the sun illuminates the veins of the rain. As the rain subsides, and then stops, the rainbow fade and gradually disappears. The colors observed in the rainbow alternate in the same sequence as in the spectrum obtained by passing the beam of sun rays through the prism. In this case, the internal (facing the surface of the Earth) the extreme region of the rainbow is painted in purple color, and the external extreme area is in red. Often over the main rainbow, another (secondary) rainbow occurs - wider and blurred. Colors in the secondary rainbow alternate in the reverse order: from the red (extreme indoor area of \u200b\u200bthe arc) to purple (extreme external region).

For an observer located on a relatively smooth earth surface, the rainbow appears under the condition that the angular height of the sun above the horizon does not exceed about 42 °. The lower the sun, the greater the corner height of the summit of the rainbow and those, therefore, more observed section of the rainbow. The secondary rainbow can be observed if the height of the sun above the horizon does not exceed about 52.

The rainbow can be considered as a giant wheel, which is both on the axis, to the imaginary straight line passing through the sun and the observer.

The dispersion is the cause of chromatic aberrations - one of the aberration of optical systems, including photographic and video lenses.

Dispersion of light in nature and art

Due to the dispersion, you can observe different colors of light.
Rainbow, whose colors are due to dispersion, is one of the key images of culture and art.
Due to the dispersion of light, you can observe the color "light game" on the edges of the diamond and other transparent faceted objects or materials.
In one degree or another, the rainbow effects are found quite often when light passes through almost any transparent items. In art, they can specially intensify, emphasize.
Decomposition of light in the spectrum (due to the dispersion) in the refraction in the prize - a fairly common topic in fine art. For example, on the cover of the Album Dark Side of The Moon Pink Floyd group depicted the refraction of light in the prism with decomposition in the spectrum.

The discovery of the dispersion was very significant in the history of science. On the tombstone of the scientist there is an inscription with such words: "Sir Isaac Newton is resting here, nobleman, who ... The first with a torch of mathematics explained the movement of the planets, the path of comets and the arrivals of the oceans.

He explored the difference in light rays and the different properties of colors that have previously suspected. ... Let the mortals rejoice that there was such a decoration of human race. "

4. Fastening

Answer questions on the topic studied.
Rubric "Think ..."
Question: Why is Raduga Round?
Compilation of "Synkievina" on the topic "Dispersion"

5. Summing up the lesson

At the end of the lesson, it is again diagnosed with "Class" coloring. To find out what the mood was at the end of the lesson, on the basis of which the "Color Tricer" diagram is drawn up and the result is compared, which mood was at the disciples at the beginning of the lesson and at the end.

6. Homework:§66

Literature:

Myakyshev G.Ya., Bukhovtsev B.B. Physics: textbook for secondary secondary school. - M.: Education, 2006.
Rymkevich A.P. Collection of tasks in physics for 9-11 high school classes. - M.: Education, 2006.
Reader physics: Tutorial For students of 8-10 secondary schools / ed. B.I. Spassky. - M.: Enlightenment, 1987.
Journal "Physics in School" No. 1/1998

The world around the world is filled with millions of diverse shades. Thanks to the properties of light, each object and the object around us has a certain color perceived by human vision. The study of light waves and their characteristics allowed people to look deeper on the nature of light and phenomena associated with it. Today we will talk about dispersion.

Nature of Light

From a physical point of view, light is a combination of electromagnetic waves with different values \u200b\u200bof length and frequency. The person's eye perceives not any light, but only one, whose wavelength length ranges from 380 to 760 nm. The remaining varieties remain invisible for us. These, for example, include infrared and ultraviolet radiation. The famous scientist Isaac Newton represented the light as a directional stream of the smallest particles. And only later it was proved that he is by its nature is a wave. However, Newton was still partly right. The fact is that light has not only wave, but also by corpuscular properties. This is confirmed by the well-known phenomenon of the photo effect. It turns out that the light stream has a two-way nature.

Color spectrum

White light, accessible to human vision, is a combination of several waves, any of which is characterized by a certain frequency and its own photon energy. In accordance with this, it can be decomposed on the waves of different colors. Each of them is called monochromatic, and a specific color corresponds to its range of length, frequency of waves and photon energy. In other words, the energy emitted by the substance (or absorbed) is distributed through the above indicators. This explains the existence of a light spectrum. For example, the green spectrum color corresponds to the frequency located in the range from 530 to 600 THz, and purple - from 680 to 790 THz.

First steps on the way to open dispersion

As mentioned above, the light stream when passing through the prism decomposes on the color spectrum, which Isaac Newton studied quite in detail in due time. The result of its research was the opening of the dispersion phenomenon in 1672. Scientific interest in the properties of light appeared before our era. The famous Aristotle has already noticed that sunlight can have different shades. The scientist argued that the nature of the color depends on the "amount of darkness" present in white light. If it is much, then the purple color occurs, and if there is little, then red. The Great Thinker also said that the main color of the light rays is white.

Studies of Newton's predecessors

Opening Newton

Thanks to the deliberate mind of this outstanding scientist, it was proved that the white light is not the main one, and that the remaining colors arise at all as a result of the interaction of light and darkness in different ratios. Newton denied these beliefs and showed that white light is composite in its structure, it is formed by all the colors of the light spectrum, called monochromatic. As a result of the passage of the light beam through the prism, the variety of colors is formed due to the decomposition of white light into the components of its wave flows. Such waves with different frequency and length are refracted in the medium in different ways, forming a certain color. Newton put experiments that are still used in physics. For example, experiments with crossed prism, using two prisms and mirrors, as well as light transmission through prism and perforated screen. Now we know that the decomposition of light on the color spectrum occurs due to the different speed of passing the waves with a different length and frequency through the transparent substance. As a result, some waves come out of the prism earlier, others - a little later, the third - even later and so on. So the light flow decomposition occurs.

Anomalous dispersion

In the future, scientists of the physicists of the year before lasting the next discovery relating to the dispersion. The Frenchman Lero discovered that in some media (in particular, in iodine pairs), the dependence expresses the dispersion phenomenon is violated. For the study of this issue, the physicist Kundt lived in Germany. For his research, he borrowed one of Newton's methods, namely, experience using two crossed prisms. The difference consisted only that instead of one of them, Kundt used a prismatic vessel with a solution of cyanine. It turned out that the refractive index during the passage of light through such prisms is increasing, and does not decrease, as happened in Newton's experiments with conventional prisms. The German scientist found out that this paradox is observed due to such a phenomenon as the absorption of light substance. In the described experiment, the Kunda absorbing medium performed a solution of cyanine, and the dispersion of light for such cases was named abnormal. In modern physics, such a term is practically not used. To date, Newton's open Newton and later, anomalous dispersion is considered as two phenomena belonging to one teaching and having a common nature.

Low-dispersed lenses

Nature of Light

From a physical point of view, light is a combination of electromagnetic waves with different values \u200b\u200bof length and frequency. The person's eye perceives not any light, but only one, whose wavelength length ranges from 380 to 760 nm. The remaining varieties remain invisible for us. These, for example, include infrared and ultraviolet radiation. The famous scientist Isaac Newton represented the light as a directional stream of the smallest particles. And only later it was proved that he is by its nature is a wave. However, Newton was still partly right. The fact is that the light has not only wave, but also corpuscular ...

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The decomposition of light in the spectrum due to the dispersion when passing through the prism (Newton's experience). This term also has other values, see Dispersion.

DISP RSIA (Light decomposition) is a phenomenon due to the dependence of the absolute refractive index of the substance from the frequency (or wavelength) of the light (frequency dispersion), or the same, the dependence of the phase light rate in the substance from the wavelength (or frequency) . It is experimentally opened by Newton around 1672, although theoretically quite well is explained significantly later.

One of the most visual examples of the dispersion is the decomposition of white light when it passes through the prism (Newton's experience). The essence of the dispersion phenomenon is the unequal speed of the spread of the light beams with different wavelengths in the transparent substance - the optical medium (while in vacuo the speed of light is always the same, regardless of the wavelength and therefore color). Usually, the greater the frequency of the wave, the greater the refractive index ...

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Newton's experiments

The first experiments with the dispersion decomposition of the world did Newton. He sent the usual beam of sunlight on the prism and received that many today see daily - Prism laid out the light beam into a variety of multi-colored colors - from red to violet. After a series of other experiments with lenses and Prism, Newton concluded that the prism does not change the sunlight, but only decomposes it to the components. But how does it work?

The fact is that the light has a certain speed. As the experience showed, the light beam consists of a variety of colors, this is the speed just different. That is, each color of the spectrum has its own speed and its wavelength. The degree of refractive to the color rays was also different. Remember how it looks ...

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Chapter 1. Light waves - lesson 5. Dispersion of light
Back to the category
Lesson 5. Light Dispersion

The refractive index does not depend on the angle of falling the light beam, but it depends on its color. It was open Newton.

By improving telescopes. Newton drew attention to that. that the image given by the lens is painted along the edges. He became interested in this and the first "investigated a variety of light rays and flowing the features of flowers, which no one even suspected" (words from the inscription on the tombstone of Newton). The rainbow color of the image given by the lens was observed, of course, to it. It was also observed that the rainbow edges have objects considered through the prism. A bundle of light rays, passed through the prism, painted around the edges.

The main experience of Newton was ingenious simple. Newton guessed to direct the luminous bunch of a small cross section on the prism. The sunlight bundle passed into the darkened ...

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Gymnasium No. 26 Dispersion of Light Performed: Student 11 in the class of Sveleov Dmitry Head: Pyrukova L.V. Tomsk-2011 In the 17th century, an idea of \u200b\u200bthe wave nature of light is developing. The first discovery, indicating the wave nature of the world, was made by the Italian scientist Francesco Grimaldi. He noticed that if on the path of a very narrow beam of the light to put the subject, then the screen does not work with a sharp shadow. The edges of the shade are blurred, in addition, colored stripes appear along the shadow. The open phenomenon of Grimaldi called the diffraction, but did not manage to explain correctly. He understood that the phenomenon observed them is in contradiction with the corpuscular theory of light, but did not decide to completely abandon this theory. Proper explanation open phenomenon associated with the theory of color vision, the foundations of which were laid out by the wonderful English scientist Isaac Newton. Dispersion of light (light decomposition) is the phenomenon of the dependence of the absolute refractive index of the substance from the wavelength of the light ...

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DISP RSIA (Light decomposition) is the phenomenon of the absolute refractive index of the substance from the wavelength of light (frequency dispersion), as well as the coordinate (spatial dispersion), or that the same, the dependence of the phase speed of light in the substance from the length Waves (or frequencies). It is experimentally opened by Newton around 1672, although theoretically quite well is explained significantly later.

red color is the maximum speed in the medium and the minimum degree of refraction, ...

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Physics lesson "Dispersion of light"

Sections: Physics

Tasks lesson:

Educational: introduce the concepts of the spectrum, the dispersion of light; Acquaint students with the history of the opening of this phenomenon. Visually demonstrate the process decomposition of a narrow light beam into components of various color shades. To identify the differences in these elements of the beam of light. Continue the formation of scientific worldview of students. Developing: Development of attention, figurative and logical thinkingMemory when studying this topic. Stimulating the cognitive motivation of students. Development of critical thinking. Educational: Education of interest in the subject; Educating the feelings of the beautiful, beauty of the surrounding world.

Type of lesson: learn lesson and primary consolidation of new knowledge.

Training Methods: Conversation, Story, Explanation, Experiment. (Information-developing)

Requirements to...

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Ministry of Science and Education of Ukraine

Ukrainian Engineering and Pedagogical Academy

Report on the topic:

Dispersion of light

Performed student c. Dre-C5-1.

Fesenko A.V.

Kharkov 2006.

Dispersion phenomenon

Dispersion of light. In a bright sunny day, close the window in the room with a dense curtain, in which we will make a small hole. Through this machine will penetrate a narrow solar beam to the room forming opposite wall Light spot. If you put on the way

glass prism, the spot on the wall will turn into a varicolored gloss, in which all the colors of the RA arcs will be presented - from purple to red (Fig. 1, F-violet, C - Blue, G - Blue, 3 - Green, J River , O-stunned, k - red).

The light dispersion is the dependence of the refractive index N substance from the frequency f (wavelength) of light or dependence ...

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Slide 1.
The word "dispersion" comes from the Latin word DisPersio, which in the literal translation means "scattering, dispelling". Dispersion of light work performed a student 11 "E" class Adelshina Ilvira

Slide 2.
Opening History Determination of Newton's Experience The feature of the passage of the light beam through the prism Basic properties Corollary Conditions Conditions of Rainbow Questions Conclusions Content

Slide 3.
The light flow during passage through the prism decomposes on the color spectrum, which Isaac Newton studied quite in detail in its time. The result of its research was the opening of the dispersion phenomenon in 1672. First steps on the way to open dispersion

Slide 4.
About 300 years ago Isaac Newton missed sun rays through the prism. No wonder on his gravestone monument, furnished in 1731 and decorated with the figures of the young men who keep his emblem in the hands the main discoveries, one figure holds a prism, and in the inscription on the monument there are words: "He ...

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Study of the dispersion of light in the 11th grade

Tishkova Svetlana Anatolyevna, teacher physics

The article is assigned to the section: Teaching Physics

This lesson is carried out at the end of the study of the "Wave Properties of Light" theme in the classes of a physico-mathematical profile.

A. Students must learn:

A bunch of white light, when passing through a substance having a refractive angle, decomposes on bundles of various chromaticities. This phenomenon is called a dispersion of light.

When falling on the border of the section of two environments, light bundles of different color are refracted differently: red - less, and purple - more.

The objective characteristic of the chroma is the frequency of the electromagnetic wave.

B. Students must learn:

Create the concept of "Light Dispersion".

Recognize light dispersion among other phenomena.

Play the dispersion of light in a specific situation.

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Light dispersion is considered as a result of the interaction of electromagnetic waves with charged particles that are part of the substances. Particles of substances make forced oscillations in an alternating electromagnetic field of the wave.

Light dispersion - the dependence of the absolute refractive index of the substance N from the frequency ...

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Laboratory Laboratory Dispersion Phenomenon Observation
In physics, the dispersion of light is the dependence of the refractive index of the substance from the length of the light wave. The most clearly demonstrates the phenomenon of the dispersion of light its decomposition under the action of any prism.

1.3. The first experiments with prisms. Presentations on the ranks of the emergence of flowers to Newton.
1.4. Newton's experiments with prisms. Newtonian theory of colors
1.5. Opening an abnormal dispersion of light. Experiments of Kundt.
Chapter II. Dispersion in nature
2.1. Rainbow
Chapter III. Experimental installation for monitoring colors
3.1. Installation Description
3.2. Device experimental installation
Conclusion
Literature
Introduction
Dispersion of light. We are always faced with this phenomenon in life, but we do not always notice this. But if you are attentive, the dispersion phenomenon always surrounds us. One of these phenomena is the usual rainbow. Probably there is no man who is not ...

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MOU " high school №28 named after G. F. KirDishcheva "

Petropavlovsk-Kamchatka urban district

Dispersion of light and color bodies

Summary of the lesson of physics in the 11th grade

Lesson studying new material, consolidation and control

Teacher Physics Maou "Secondary School No. 28 named after G. F. Kirdishchev" Yuryeva O. L.

Sergey Yesenin

I do not regret, do not call, do not cry,
Everything will pass as with white apple trees smoke.
Fading gold embraced
I will not be more young.

You will not be so fight now,
Heart touched by chill
And country of birch sitz
Do not lure a barefoot.

Spirighter spirit! You are less and less
Moving a flame of mouth
Oh, my lost freshness,
Blue eye and flood feelings!

I now became a storm in the worst,
My life, Ile you dreamed me?
As if I am a spring bunker
Specked on a pink horse.

All of us, all of us in this world are damaged,
Quietly pour ...

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What waves are called coherent?

waves having the same frequency

waves having the same amplitude

waves having the same frequency and constant phase difference

Polarization of light proves that light -
flow of neutral particles
cross wave
longitudinal waves

What is called diffraction of light?
white light decomposition in spectrum with a glass prism
strengthening or weakening light when overlaying two coherent waves
envelope with light obstacles

Spectrum colors (red - k, orange - o, blue - with, yellow - f, blue - g, green - s, purple - f) in order loss of wavelengths correctly listed in the answer:
1.F, s, g, s, g, oh, to
k, oh, z, s, g, s, f
f, g, s, s, g, oh, to

Rainbow painting of thin films of petroleum products in puddles is caused by phenomenon
diffraction
dispersion
interference

Enlightenment lenses is due to ...

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Essay: Theme of the lesson: "The light is a flow of particles"
Teacher Pyrukova L.V., MOU Gymnasium № 26

Theme of the lesson: "The light is a flow of particles"

Type of lesson: Modified debate

The organization of "modified" debates admits some changes to the rules, you can increase or reduce the number of players in the teams; Audience questions are permissible, support groups are organized to which teams can contact during the game, the group of experts performs the functions of refereeing, develops a compromise solution when it is necessary to implement educational purposes. The main stages of the organization of the educational process based on the use of the debate techniques are: orientation (select the topic); preparation for conducting; carrying out debates; Discussion of the game.

^ Objectives of the lesson:

Generalization and systematization of knowledge

Light dispersion (decomposition of light) is the phenomenon of the dependence of the absolute refractive index of the substance from the light wavelength (frequency dispersion), and also, from the coordinate (spatial dispersion), or that the same, the dependence of the phase light rate in the substance from the wavelength ( or frequency). It is experimentally opened by Newton around 1672, although theoretically quite well is explained significantly later.

Usually, the greater the frequency of the wave, the greater the refractive index of the medium and the less of its speed of light in it:

Red color Maximum speed in the medium and minimum degree of refraction,

Violet color Minimum light speed in the medium and the maximum degree of refraction.

Anomalous dispersion - View of the dispersion of light, in which the refractive index of the medium decreases with increasing frequency of light oscillations.

where is the refractive index of the medium,

- The frequency of the wave.

According to modern ideas And normal, and abnormal dispersions are the phenomena of a single nature. This view is based on the electromagnetic theory of light, on the one hand, and on the electronic theory of the substance, on the other. The term "anomalous dispersion" retains today only historical meaningSince the "normal dispersion" is the dispersion of the wavelengths at which the light absorb is absorbed by this substance, and "anomalous dispersion" is a dispersion in the region of the light absorption bands.

The difference between the anomalous dispersion from the normal is that in some substances (for example in a vapor) during the decomposition of light during the passage of the prism, the blue rays are refracted less than the red, and the other rays are absorbed by the substance and escape the observation. In normal dispersion, on the contrary, the red light is refracted by an angle, smaller than the one on which purple is refracted. (See the topic "Dispersion").

The dispersion of light allowed for the first time it is quite convincingly to show the composite nature of white light. White light decomposes on the spectrum and as a result of passing through the diffraction grid or reflection from it (this is not associated with the dispersion phenomenon, but is explained by nature diffraction). The diffraction and prismatic spectra are somewhat different: the prismatic spectrum is compressed in the red part and stretched in purple and is located in descending order of the wavelength: from red to violet; Normal (diffraction) spectrum is uniform in all areas and is located in ascending order of wavelengths: from violet to red.

The absorption of light is the phenomenon of the weakening of the brightness of the light when it passes through the substance or when reflected from the surface. The absorption of light occurs due to the transformation of the energy of the light wave in internal energy Substances or in the energy of secondary radiation having a different spectral composition and other direction of distribution.

Law of Bugger - Lambert - Bera - physical Lawdetermining the weakening of the parallel monochromatic beam of light when it is propagated in the absorbing medium.

The law is expressed by the following formula:

where I0 is the intensity of the incoming beam, L is the thickness of the substance layer through which the light passes, Kλ is the absorption indicator.

The absorption indicator is the coefficient characterizing the properties of the substance and depending on the wavelength λ of the absorbed light. This dependence is called the absorption spectrum of the substance.

The color is a high-quality subjective characteristic of the electromagnetic radiation of the optical range, determined on the basis of an emerging physiological visual sensation, and depending on a number of physical, physiological and psychological factors. Individual color perception is determined by its spectral composition, as well as a color and bright-like contrast with surrounding light sources, as well as non-leaving objects. Such phenomena as metamery are very important; Features of the human eye, and psyche.

The absorption spectrum is the dependence of the intensity of the radiation absorbed by the substance (both electromagnetic and acoustic) from the frequency. It is associated with energy transitions in the substance. The absorption spectrum is characterized by the so-called absorption coefficient that depends on the frequency and is defined as the reverse value by the distance on which the intensity of the transmitted radiation flux is reduced in e times. For different materials The absorption coefficient and its dependence on the wavelength are different ..

From today's positions normal dispersion - this is dispersion away from the wavelengths in which absorption occurs sveta this substance, whereas anomalous dispersion - this is dispersion In the area of \u200b\u200babsorption bands sveta substance.