Tatiana Osipova
Educational and research project "Microscope"

Informative– research project« Microscope»

Type project: short-term research

Duration: 4 weeks

Participants: teacher and students of the middle group "Flowers".

Target:

Explore possibilities microscope for objects of living and inanimate nature

Tasks:

1. Find out the history of creation microscope.

2. Find out what they are made of microscopes, and what they can be.

3. Conduct experiments with research elements.

Relevance project

Among preschoolers, it is very difficult to find those who are not interested in the structure of all life on Earth. Every day, children ask dozens of difficult questions to their moms and dads. Curious kids are definitely interested in All: what animals and plants are made of, how nettles sting, why some leaves are smooth and others are fluffy, how a grasshopper chirps, why a tomato is red and a cucumber is green. And exactly microscope will make it possible to find answers to many children's “whys”. It’s much more interesting not just to listen to my mother’s story about some cells, but to look at these cells with my own eyes. It's hard to even imagine how breathtaking the pictures can be seen through the eyepiece. microscope, what amazing discoveries your little naturalist will make.

Classes with microscope will help the child expand his knowledge about the world around him, create the necessary conditions for cognitive activity, experimentation, systematic observation of all kinds of living and non-living objects. The baby will develop curiosity and interest in the phenomena happening around him. He will pose questions and look for answers to them on his own. A little explorer will be able to look at the simplest things in a completely different way, to see their beauty and uniqueness. All this will become a strong basis for further development and learning.

The project is based on the example of a microscope show children the possibilities of using instruments to study objects and phenomena of the surrounding world, broaden their horizons, involve them in experimental and design activities using microscope.

Implementation mechanism project

Implementation project was carried out through the selection of materials and experiments.

Expected results

Increasing the level of environmental education of preschool children.

A desire to experiment with using microscope.

Gain practical knowledge of how to use microscope.

Main part

History of creation microscope.

Microscope(from Greek - small and looking)- an optical device for obtaining magnified images of objects invisible to the naked eye.

This is a fascinating activity - looking at something in microscope. But who came up with this miracle - microscope?

In the Dutch city of Middelburg there lived a spectacle master three hundred and fifty years ago. He patiently polished glass, made glasses and sold them to everyone who needed it. He had two children - two boys. They loved to climb into their father's workshop and play with his tools and glass, although this was forbidden to them. And then one day, when their father was away somewhere, the guys made their way to his workbench as usual - is there anything new that they can have fun with? On the table lay glasses prepared for glasses, and in the corner lay a short copper a tube: the master was going to cut out rings from it - frames for glasses. The guys squeezed spectacle glass into the ends of the tube. The older boy put the pipe to his eye and looked at the page of the open book that lay right there on the table. To his surprise, the letters became huge. The younger one looked into the phone and shouted, stricken: he saw a comma, but what a comma - it looked like a fat worm! The guys pointed the tube at the glass dust left after polishing the glass. And they saw not dust, but a bunch of glass grains. The tube was right magical: She greatly enlarged all objects. The boys told their father about their discovery. He didn't even scold their: He was so surprised by the extraordinary property of the pipe. He tried to make another tube with the same glasses, long and extendable. The new tube increased the magnification even better. This was the first microscope. It was accidentally invented in 1590 by the spectacle maker Zacharias Jansen, or rather, by his children.

Microscope can be called a device that reveals secrets. Microscopes they looked different in different years, but every year they became more and more complex, and they began to have many details.

Kinds microscopes.

There are many different types of magnifying devices. For example, magnifying glasses, telescopes, binoculars, microscopes. What kind are there? microscopes?

There are 3 types microscopes.

1. Optical microscope, which was invented back in the 16th century. It consists of 2 lenses, one of which is intended for the eye, the other for the object that you want to view.

2. Electronic microscope was invented at the beginning of the 20th century. The observed object is scanned by an electron laser, which analyzes the particles using a computer that recreates a three-dimensional image of the observed object.

3. Scanning tunnel microscope and atomic force microscope were invented later, with their help you can see infinitesimal particles.

Professions in which it is used microscope.

Chemists use microscope to study molecules. By seeing what is invisible to the naked eye, they can mix molecules and create new materials called plastics.

Doctors and biologists use microscope to understand the functioning of living organisms. With help microscope, doctors study various diseases and create medicines, as well as perform surgical operations that require special precision.

An agricultural engineer studies food molecules. This helps create new products from existing food types. Microscope It is also used to control food quality, which can prevent many diseases.

Criminologists investigate crimes using scientific methods. They use evidence microscope, left at the crime scene. Microscope helps collect and study fingerprints.

Microscope

In the laboratory of our kindergarten we will work with optical microscope, which runs on batteries. The main task of this microscope- show the object in an enlarged view.

I introduced the children to this microscope, told me what it consists of and how it works.

Children found out what items are included in his set This:

Transparent plates, with their help you can save samples that have been studied previously;

Tweezers and stirring stick;

Needle, scalpel and micro-cutting;

Petri dish.

Before conducting research, children learned the rules of working with microscope:

1. Put microscope on a flat surface.

2. Check the backlight. Place the sample on the stand and clamp the plate, turn the control to obtain 150x magnification.

3. Look through the eyepiece. Use the focus control to move the lens as close to the plate as possible without touching it. Then turn the knob in the opposite direction until the image becomes clear.

4. Using light filters, you can change the colors of the objects in question.

5. If the image is too dark, you can adjust the backlight brightness.

6. Select an object to study and focus.

Experiments with microscope.

Under microscope you can literally look at all this interesting and informative.

1. Plant composition

Everything, from seeds to leaves of trees and other plants, is alive. These items are made up of thousands of tiny cells that help plants grow, develop and reproduce. These are the ones that are visible in microscope like little bricks. Why were they called cells? This name was invented by the English botanist R. Hooke. Looking under microscope section of cork, he noticed that it consists of “many boxes.” He also called these “boxes” cameras etc. cells.

Microscope will help you learn that all living things are made up of cells. Under microscope you can see not only the cell, but also examine its structure.

Experiment 1. Leaf.

The leaves are the nose of the tree. They have 2 main ones functions: absorption of sunlight, carbon dioxide and oxygen. Let's take a good green maple leaf. Let's cut a small piece from it. Let's place this piece on the plate, fix it on a stand, and use direct lighting.

The leaf has a simple structure. It consists of a cutting that extends from a tree trunk or branch. The veins are the skeleton of the plant. Platinum sheet is the main fabric of the sheet. On each side of the leaf there are 2 types of cells that are responsible for both functions. On the outside there are chloroplasts, which are responsible for capturing sunlight. On the inside there are stomata that absorb carbon dioxide during the day and oxygen at night.

Why are the leaves green? Chlorophyll is the green pigment of leaves. It's something like "blood" leaf. In the fall, the leaf will turn red or yellow as the chlorophyll content decreases.

2. People and animals

Humans have many similarities with animals. They consist of identical cells. These cells allow them to live, think, move and reproduce. Let's conduct an experiment that will open the wonderful world of animal cells.

Experiment 2. Cells in the mouth

Saliva is made up of many animal cells. Surprisingly, they are almost no different from plant cells!

Using a clean cotton swab, collect some saliva from the inside of your cheek. Place a small amount of the resulting sample on the plate, spread it over it, cover it with another transparent plate and let it dry for a few minutes. We will carry out observations with a magnification of 400 times and using reflected light.

Saliva makes it easy to observe animal cells. Most of the cells in this sample died, but retained their structure, similar to the structure of plant cells - the nucleus, which is the vital center, which is immersed in the cytoplasm. Inside the cytoplasm there are nutrients that allow the cell to live, but, unfortunately, are not visible in microscope. The membrane protects the cell. A distinctive feature from plant cells is that animal cells do not have a regular shape and can be of different sizes.

What other cells live in your body? Your body is made up of a specific set of cells. For example, red blood cells are blood cells that do not have a nucleus, and the brain consists of cells called neurons.

Items in your house.

There are a lot of interesting items in your home. In the closet, in the refrigerator, in the living room there are many objects with which you can experiment.

Experience 3. Sugar in food.

All children love sweets, breakfast cereals or chocolate spread. All these products contain sugar

You will need to make two samples. Place sugar on the first and chocolate powder on the second. (cocoa). We will conduct the experiment at low magnification.

Under microscope Sugar particles can be discerned in cocoa powder. These are small transparent pieces against a background of chocolate granules. They make up almost 65% of cocoa powder. In fact, this is exactly the sugar that we add to tea and coffee. Chocolate powder is not the sweetest product. For example, there are 9 sugars in a bottle of soda. In addition, one cookie contains 1 piece of sugar, and candies consist almost entirely of it. Therefore, to stay healthy, you should not overuse these products.

What fruits are the sweetest? There are 7 pieces of sugar per 100g of dates. This is followed by grapes and banana. But strawberries, on the contrary, contain the least amount of sugar.

This is where our research ended. We took photographs of all the objects we examined under microscope.

Conclusion

Exploring different objects under microscope, Human discovers the nature of life itself. By doing this project, we learned the history of the creation of the first microscope, and which people now use in modern life.

Learned to use optical microscope– a device for obtaining magnified images of objects invisible to the naked eye. We learned what it consists of and how to work with it. We conducted several experiments to study enlarged objects. Indeed, it is a fascinating activity to look at something in microscope.

conclusions:

1. Met with an interesting history of invention microscope.

2. We found out what they are made of microscopes, and what they are.

3. We did some very interesting and educational experiences.

4. Microscope is an interesting thing!

A microscope is an optical device that allows you to obtain magnified images of small objects or their details that cannot be seen with the naked eye.

Literally, the word “microscope” means “to observe something small” (from the Greek “small” and “I look”).

The human eye, like any optical system, is characterized by a certain resolution. This is the smallest distance between two points or lines when they do not yet merge, but are perceived separately from each other. With normal vision at a distance of 250 mm, the resolution is 0.176 mm. Therefore, our eye is no longer able to distinguish all objects whose size is less than this value. We cannot see plant and animal cells, various microorganisms, etc. But this can be done with the help of special optical instruments - microscopes.

How does a microscope work?

A classic microscope consists of three main parts: optical, lighting and mechanical. The optical part consists of eyepieces and lenses, the lighting part includes light sources, a condenser and a diaphragm. The mechanical part usually includes all other elements: a tripod, a revolving device, a stage, a focusing system and much more. All together allows us to conduct research into the microworld.

What is a “microscope diaphragm”: let’s talk about the lighting system

For observing the microworld, good lighting is as important as the quality of the microscope's optics. LEDs, halogen lamps, mirror - different lighting sources can be used for a microscope. Each has its own pros and cons. The backlight can be top, bottom or combined. Its location affects which microscopic specimens can be studied using a microscope (transparent, translucent or opaque).

Under the stage on which the sample is placed for research, there is a microscope diaphragm. It can be disk or iris. The diaphragm is designed to adjust the intensity of illumination: it can be used to adjust the thickness of the light beam coming from the illuminator. A disk diaphragm is a small plate with holes of different diameters. It is usually installed on amateur microscopes. The iris diaphragm consists of many blades, with which you can smoothly change the diameter of the light transmitting hole. It is more common in professional-grade microscopes.

Optical part: eyepieces and lenses

Lenses and eyepieces are the most popular spare parts for a microscope. Although not all microscopes support changing these accessories. The optical system is responsible for forming an enlarged image. The better and more perfect it is, the clearer and more detailed the picture becomes. But the highest level of optical quality is needed only in professional microscopes. For amateur research, standard glass optics are sufficient, providing magnification up to 500-1000 times. But we recommend avoiding plastic lenses - the image quality in such microscopes is usually disappointing.

Mechanical elements

Any microscope contains elements that allow the researcher to control the focus, adjust the position of the sample under study, and adjust the working distance of the optical device. All this is part of the mechanics of the microscope: coaxial focusing mechanisms, drug driver and drug holder, sharpness adjustment knobs, stage and much more.

History of the creation of the microscope

It is not known exactly when the first microscope appeared. The simplest magnifying devices - biconvex optical lenses, were found during excavations on the territory of Ancient Babylon.

It is believed that the first microscope was created in 1590 by the Dutch optician Hans Jansen and his son Zachary Jansen. Since lenses in those days were polished by hand, they had various defects: scratches, unevenness. Defects on the lenses were looked for using another lens - a magnifying glass. It turned out that if you look at an object using two lenses, it is magnified many times over. By mounting 2 convex lenses inside one tube, Zachary Jansen received a device that resembled a spyglass. At one end of this tube there was a lens that served as an objective lens, and at the other there was an eyepiece lens. But unlike a telescope, Jansen’s device did not bring objects closer, but magnified them.

In 1609, Italian scientist Galileo Galilei developed a compound microscope with convex and concave lenses. He called it "occhiolino" - small eye.

10 years later, in 1619, the Dutch inventor Cornelius Jacobson Drebbel designed a compound microscope with two convex lenses.

Few people know that the microscope received its name only in 1625. The term “microscope” was proposed by Galileo Galilei’s friend, the German doctor and botanist Giovanni Faber.

All microscopes created at that time were quite primitive. Thus, Galileo's microscope could magnify only 9 times. Having improved Galileo's optical system, the English scientist Robert Hooke in 1665 created his own microscope, which already had a 30-fold magnification.

In 1674, the Dutch naturalist Antonie van Leeuwenhoek created a simple microscope that used only one lens. It must be said that creating lenses was one of the scientist’s hobbies. And thanks to his high skill in grinding, all the lenses he made were of very high quality. Leeuwenhoek called them “microscopy”. They were small, about the size of a fingernail, but could magnify 100 or even 300 times.

Leeuwenhoek's microscope was a metal plate with a lens in the center. The observer looked through it at the sample fixed on the other side. And although working with such a microscope was not entirely convenient, Leeuwenhoek was able to make important discoveries with the help of his microscopes.

At that time, little was known about the structure of human organs. With the help of his lenses, Leeuwenhoek discovered that blood consists of many tiny particles - red blood cells, and muscle tissue - from the finest fibers. In the solutions, he saw tiny creatures of different shapes that moved, collided and scattered. Now we know that these are bacteria: cocci, bacilli, etc. But before Leeuwenhoek this was not known.

In total, scientists made more than 25 microscopes. 9 of them have survived to this day. They are capable of magnifying images 275 times.

Leeuwenhoek's microscope was the first microscope that was brought to Russia on the orders of Peter I.

Gradually the microscope was improved and acquired a form close to the modern one. Russian scientists also made a huge contribution to this process. At the beginning of the 18th century in St. Petersburg, improved designs of microscopes were created in the workshop of the Academy of Sciences. Russian inventor I.P. Kulibin built his first microscope without any knowledge of how it was done abroad. He created the production of glass for lenses and invented devices for grinding them.

The great Russian scientist Mikhail Vasilyevich Lomonosov was the first Russian scientist to use a microscope in his scientific research.

There is probably no clear answer to the question “Who invented the microscope?” The best scientists and inventors of different eras contributed to the development of microscopy.

The article talks about what a microscope is, what it is needed for, what types there are and the history of its creation.

Ancient times

In the history of mankind, there have always been those who were not satisfied with the biblical description of the structure of the world, who wanted to understand for themselves the nature of things and their essence. Or who was not seduced by the fate of an ordinary peasant or fisherman, like the same Lomonosov.

Various disciplines became most widespread during the Renaissance, when people began to realize the importance of studying the world around them and other things. Various optical devices, such as telescopes and microscopes, especially helped them in this. So what is a microscope? Who created it and where is this device used in our time?

Definition

First, let's look at the official definition itself. According to him, a microscope is a device for obtaining magnified images or their structure. It differs from the same telescope in that it is needed to study small and nearby objects, and not distant cosmic distances. The name of the author of this invention is not known for certain, but history contains references to several people who were the first to use and design it. According to them, in 1590, a certain Dutchman named John Lippershey presented his invention to the general public. Its authorship is also attributed to Zachary Jansen. And in 1624, the well-known Galileo Galilei also designed a similar device.

We figured out what a microscope is, but how did it influence science? Almost the same as its “relative” telescope. Although primitive, this device made it possible to overcome the imperfections of the human eye and look into the microworld. With its help, many discoveries were later made in the fields of biology, entomology, botany and other sciences.

What is a microscope is now clear, but where else are they used?

The science

Biology, physics, chemistry - all these areas of science sometimes require a look into the very essence of things that our eye or a simple magnifying glass cannot see. It is difficult to imagine modern medicine without these devices: with their help, discoveries are made, types of diseases and infections are determined, and recently it was even possible to “photograph” a chain of human DNA.

In physics, everything is somewhat different, especially in those areas that work on the study of elementary particles and other small objects. There, the laboratory microscope is somewhat different from the usual ones, and the usual ones help little; they have long been replaced by electronic and the latest probing ones. The latter allow not only to obtain an impressive magnification, but even to register individual atoms and molecules.

This also includes forensic science, which needs these devices to identify evidence, make detailed comparisons of fingerprints, and so on.

Researchers of the ancient world, such as paleontologists and archaeologists, also cannot do without microscopes. They need them for a detailed study of the remains of plants, bones of animals and people, and man-made products of past eras. And by the way, a powerful laboratory microscope can be freely purchased for your own use. True, not everyone can afford them. Let's look at the types of these devices in more detail.

Kinds

The first, main and most ancient is optical light. Similar devices are still available in any school biology class. It consists of a set of lenses with adjustable distance and a mirror to illuminate the object. Sometimes it is replaced by an independent light source. The essence of such a microscope is to change the wavelength of the visible optical spectrum.

The second one is electronic. It is much more complicated. In simple terms, the wavelength of visible light is 390 to 750 nm. And if the object, for example, is a smaller cell of a virus or another living organism, then the light will simply bend around it and will not be able to reflect normally. And such a device bypasses such limitations: using a magnetic field, it makes light waves “thinner,” which is why the tiniest objects can be seen. This is especially true in a science such as biology. This kind of microscope is much superior to optical light microscopes.

And the third is the probing type. To put it simply, this is a device in which the surface of a particular sample is “probed” by a probe and, based on its movements and vibrations, a three-dimensional or raster image is compiled.

The human eye is designed in such a way that it is not able to clearly see an object and its details if its dimensions are less than 0.1 mm. But in nature there are various microorganisms, cells of both plant and animal tissues and many other objects, the sizes of which are much smaller. To see, observe and study such objects, a person uses a special optical device called microscope, which allows you to magnify the image of objects invisible to the human eye many hundreds of times. The very name of the device, consisting of two Greek words: small and I look, speaks of its purpose. Thus, an optical microscope is capable of magnifying the image of an object 2000 times. If the object being studied, for example a virus, is too small and an optical microscope is not enough to magnify it, modern science uses an electron microscope, which allows you to magnify the observed object by 20,000-40,000 times.

The invention of the microscope is primarily associated with the development of optics. The magnifying power of curved surfaces was known as early as 300 BC. e. Euclid and Ptolemy (127-151), however, these optical properties were not used at that time. It was not until 1285 that the first glasses were invented by the Italian Salvinio degli Arleati. There is information that the first microscope-type device was created in the Netherlands by Z. Jansen around 1590. Taking two convex lenses, he mounted them inside one tube, using a retractable tube to achieve focusing on the object being studied. The device provided a tenfold magnification of the object, which was a real achievement in the field of microscopy. Jansen made several of these microscopes, significantly improving each subsequent device.

In 1646, an essay by A. Kircher was published, in which he described the invention of the century - a simple microscope, called “flea glass”. The magnifying glass was inserted into a copper base on which the stage was mounted. The object being studied was placed on a table, under which there was a concave or flat mirror that reflected the sun's rays onto the object and illuminated it from below. The magnifying glass was moved with a screw until the image of the object became clear.

Complex microscopes, created from two lenses, appeared in the early 17th century. Many facts indicate that the inventor of the complex microscope was the Dutchman K. Drebel, who was in the service of King James I of England. Drebel's microscope had two glasses, one (lens) facing the object being studied, the other (eyepiece) facing the observer's eye. In 1633, the English physicist R. Hooke improved the Drebel microscope, adding a third lens, called the collective. This microscope became very popular; most microscopes of the late 17th and early 18th centuries were made according to its design. By examining thin sections of animal and plant tissue under a microscope, Hooke discovered the cellular structure of organisms.

And in 1673-1677, the Dutch naturalist A. Leeuwenhoek, using a microscope, discovered a previously unknown huge world of microorganisms. Over the years, Leeuwenhoek made about 400 simple microscopes, which were small biconvex lenses, some of them less than 1 mm in diameter, made from a glass ball. The ball itself was ground on a simple grinding machine. One of these microscopes, giving 300x magnification, is kept in Utrecht in the university museum. Exploring everything that caught his eye, Leeuwenhoek made great discoveries one after another. By the way, the creator of the telescope, Galileo, while improving the telescope he created, discovered in 1610 that when extended, it significantly magnified small objects. By changing the distance between the eyepiece and the lens, Galileo used the tube as a kind of microscope. Today it is impossible to imagine human scientific activity without the use of a microscope. The microscope has found wide application in biological, medical, geological and materials science laboratories.

MICROSCOPE
an optical instrument with one or more lenses for producing magnified images of objects not visible to the naked eye. Microscopes can be simple or complex. A simple microscope is a single lens system. A simple microscope can be considered an ordinary magnifying glass - a plano-convex lens. A compound microscope (often called simply a microscope) is a combination of two simple ones. A compound microscope provides greater magnification than a simple one and has greater resolution. Resolution is the ability to distinguish details of a sample. An enlarged image with no details visible provides little useful information. A complex microscope has a two-stage design. One system of lenses, called an objective, is brought close to the sample; it creates a magnified and resolved image of the object. The image is further magnified by another lens system called an eyepiece, which is placed closer to the viewer's eye. These two lens systems are located at opposite ends of the tube.

Working with a microscope. The illustration shows a typical biological microscope.
The tripod stand is made in the form of a heavy casting, usually horseshoe-shaped. A tube holder is attached to it on a hinge, carrying all the other parts of the microscope. The tube in which the lens systems are mounted allows them to be moved relative to the sample for focusing. The lens is located at the lower end of the tube. Typically, a microscope is equipped with several objectives of different magnifications on a turret, which allows them to be installed in a working position on the optical axis. The operator, examining a sample, usually starts with the lens that has the lowest magnification and the widest field of view, finds the details that interest him, and then examines them using a lens with higher magnification. The eyepiece is mounted on the end of a retractable holder (which allows you to change the length of the tube when necessary). The entire tube with objective and eyepiece can be moved up and down to focus the microscope. The sample is usually taken as a very thin transparent layer or section; it is placed on a rectangular glass plate, called a slide, and covered on top with a thinner, smaller glass plate, called a coverslip. The sample is often stained with chemicals to increase contrast. The glass slide is placed on the stage so that the sample is located above the central hole of the stage. The stage is usually equipped with a mechanism for smoothly and accurately moving the sample across the field of view. Under the object stage there is a holder for the third lens system - a condenser, which concentrates the light on the sample. There can be several condensers, and an iris diaphragm is located here to adjust the aperture. Even lower is a lighting mirror installed in a universal joint, which reflects the light of the lamp onto the sample, due to which the entire optical system of the microscope creates a visible image. The eyepiece can be replaced with a photo attachment, and then the image will be formed on photographic film. Many research microscopes are equipped with a special illuminator, so that an illumination mirror is not necessary. The magnification of a microscope is equal to the product of the objective magnification and the eyepiece magnification. For a typical research microscope, the magnification of the eyepiece is 10, and the magnification of the objectives is 10, 45 and 100. Therefore, the magnification of such a microscope ranges from 100 to 1000. The magnification of some microscopes reaches 2000. Increasing the magnification even more does not make sense, since the resolving power not improving; on the contrary, the image quality deteriorates.
Theory. A consistent theory of the microscope was given by the German physicist Ernst Abbe at the end of the 19th century. Abbe found that resolution (the minimum possible distance between two points that are separately visible) is given by

where R is the resolution in micrometers (10-6 m), l is the wavelength of light (created by the illuminator), μm, n is the refractive index of the medium between the sample and the lens, and a is half of the input angle of the lens (the angle between the outer rays of the conical light beam , included in the lens). Abbe called the quantity numerical aperture (it is denoted by the symbol NA). From the above formula it is clear that the greater the NA and the shorter the wavelength, the smaller the resolved details of the object under study. The numerical aperture not only determines the resolution of the system, but also characterizes the lens aperture: the light intensity per unit image area is approximately equal to the square of NA. For a good lens, the NA value is approximately 0.95. The microscope is usually designed so that its total magnification is approx. 1000 NA.
Lenses. There are three main types of lenses, differing in the degree of correction of optical distortions - chromatic and spherical aberrations. Chromatic aberration occurs when light waves of different wavelengths are focused at different points on the optical axis. As a result, the image appears colored. Spherical aberrations are caused by the fact that light passing through the center of the lens and light passing through its peripheral part are focused at different points on the axis. As a result, the image appears unclear. Achromatic lenses are currently the most common. In them, chromatic aberrations are suppressed through the use of glass elements with different dispersions, ensuring the convergence of the extreme rays of the visible spectrum - blue and red - into one focus. A slight coloration of the image remains and sometimes appears as faint green stripes around the object. Spherical aberration can only be corrected for one color. Fluorite lenses use glass additives to improve color correction to the point that coloration is almost completely eliminated from the image. Apochromatic lenses are the lenses with the most complex color correction. They not only almost completely eliminate chromatic aberrations, but also correct spherical aberrations for not one, but two colors. The magnification of apochromats for blue is slightly greater than for red, and therefore they require special “compensating” eyepieces. Most lenses are "dry", i.e. they are designed to work in conditions where the gap between the lens and the sample is filled with air; the NA value for such lenses does not exceed 0.95. If a liquid (oil or, more rarely, water) is introduced between the objective and the sample, an “immersion” objective is obtained with an NA value as high as 1.4 and a corresponding improvement in resolution. Currently, the industry produces various kinds of special lenses. These include flat-field lenses for microphotography, stress-free (relaxed) lenses for working in polarized light, and lenses for examining opaque metallurgical samples illuminated from above.
Condensers. The condenser forms a cone of light directed at the sample. Typically, a microscope is equipped with an iris diaphragm to match the aperture of the light cone with the aperture of the objective, thereby providing maximum resolution and maximum image contrast. (Contrast is as important in microscopy as it is in television technology.) The simplest condenser, quite suitable for most general-purpose microscopes, is the two-lens Abbe condenser. Larger aperture lenses, especially oil immersion lenses, require more complex corrected condensers. Maximum aperture oil objectives require a special condenser that has oil immersion contact with the bottom surface of the slide on which the sample rests.
Specialized microscopes. Due to the various requirements of science and technology, many special types of microscopes have been developed. A stereoscopic binocular microscope, designed to obtain a three-dimensional image of an object, consists of two separate microscopic systems. The device is designed for small magnification (up to 100). Typically used for assembly of miniature electronic components, technical inspection, surgical operations. A polarizing microscope is designed to study the interaction of samples with polarized light. Polarized light often makes it possible to reveal the structure of objects that lies beyond the limits of conventional optical resolution. A reflective microscope is equipped with mirrors instead of lenses that form an image. Since it is difficult to make a mirror lens, there are very few fully reflective microscopes, and mirrors are currently used mainly only in attachments, for example, for microsurgery of individual cells. Fluorescent microscope - illuminating the sample with ultraviolet or blue light. The sample, absorbing this radiation, emits visible luminescence light. Microscopes of this type are used in biology, as well as in medicine - for diagnostics (especially cancer). The dark-field microscope circumvents the difficulties associated with the fact that living materials are transparent. The sample is viewed under such “oblique” lighting that direct light cannot enter the lens. The image is formed by light diffracted by an object, causing the object to appear very light against a dark background (with very high contrast). A phase contrast microscope is used to examine transparent objects, especially living cells. Thanks to special devices, part of the light passing through the microscope turns out to be phase-shifted by half the wavelength relative to the other part, which determines the contrast in the image. An interference microscope is a further development of the phase contrast microscope. It involves interference between two light beams, one of which passes through the sample and the other is reflected. This method produces colored images that provide very valuable information when studying living material. see also
ELECTRON MICROSCOPE;
OPTICAL INSTRUMENTS;
OPTICS.
LITERATURE
Microscopes. L., 1969 Design of optical systems. M., 1983 Ivanova T.A., Kirillovsky V.K. Design and control of microscope optics. M., 1984 Kulagin S.V., Gomenyuk A.S. and others. Optical-mechanical devices. M., 1984

Collier's Encyclopedia. - Open Society. 2000 .

See what "MICROSCOPE" is in other dictionaries:

Microscope... Spelling dictionary-reference book

MICROSCOPE- (from the Greek mikros small and skopeo I look), an optical instrument for studying small objects that are not directly visible to the naked eye. There are simple microscopes, or magnifying glasses, and complex microscopes, or microscopes in the proper sense. Magnifying glass... ... Great Medical Encyclopedia

microscope- a, m. microscope m.gr. mikros small + skopeo I look. An optical device with a system of highly magnifying glasses for viewing objects or parts of them that are not visible to the naked eye. BAS 1. Microscope, fine vision. 1790. Kurg. // Maltseva 54.… … Historical Dictionary of Gallicisms of the Russian Language

MICROSCOPE (Microscopus), a small constellation in the southern sky. Its brightest star has a magnitude of 4.7. MICROSCOPE, an optical device that allows you to obtain a magnified image of small objects. The first microscope was created in 1668... ... Scientific and technical encyclopedic dictionary

- (Greek, from mikros small, and skopeo I look). A physical apparatus for examining the smallest objects, which, through it, appear in an enlarged form. Dictionary of foreign words included in the Russian language. Chudinov A.N.,... ... Dictionary of foreign words of the Russian language

- (from micro... and...scope) an instrument that allows you to obtain an enlarged image of small objects and their details that are not visible to the naked eye. The magnification of the microscope, reaching 1500-2000, is limited by diffraction phenomena. Unarmed... ... Big Encyclopedic Dictionary

Microtextiles, orthoscope Dictionary of Russian synonyms. microscope noun, number of synonyms: 11 biomicroscope (1) ... Synonym dictionary

MICROSCOPE, huh, husband. A magnifying device for examining objects that are indistinguishable to the naked eye. Optical m. Electronic m. (giving an enlarged image using electron beams). Under a microscope (in a microscope) examine what n. |… … Ozhegov's Explanatory Dictionary

- (from the Greek mikros small and skopeo I look), optical. a device for obtaining highly magnified images of objects (or details of their structure) invisible to the naked eye. Various types of M. are intended for the detection and study of bacteria,... ... Physical encyclopedia

MICROSCOPE, microscope, man. (from the Greek mikros small and skopeo I look) (physical). An optical device with a system of highly magnifying glasses for viewing objects that cannot be seen with the naked eye. Ushakov's Explanatory Dictionary.... ... Ushakov's Explanatory Dictionary

An optical device for obtaining magnified images of objects that are not visible to the naked eye. In microbiol. light and electronic microscopy are used. One of the main indicators of microscopy is resolution - the ability to distinguish between two neighboring objects... ... Dictionary of microbiology