People have long tried to understand how the world around them works. Conducted research, looked inside living beings and drew conclusions. This is how theoretical material was accumulated, which became the basis for many sciences.
The methods they used were mostly observation and experiment. However, it quickly became obvious that the treasury of knowledge would remain only half full, unless some more complex, technically advanced devices were invented. Those that will allow you to look inside, reveal the deep mechanisms and consider the features of the device of various objects and living beings.
Methods of study in biology
The main ones include the following:
- Historical method.
- Description.
- Observation.
- Comparison.
- Experiment.
Most of them require the intervention of new technical devices that would make it possible to obtain a picture in a multiply enlarged size. That is, to put it simply, one should use differentmagnifying devices. That is why the need to construct them was obvious.
After all, this is the only way people could understand how the life processes of such tiny creatures as protozoa and bacteria, microscopic fungi, lichens and other living organisms take place.
Modern varieties of appliances
Among the variety of technical designs, magnifying devices occupy a special place. After all, it is difficult to reach the truth and prove this or that theory without them, especially when it comes to the microworld.
Modern technologies offer the following types of such devices:
1. Loupes. The structure of magnifying devices of this type is quite simple, so they were the first among analog ones in action.
2. Microscopes. Today there are several varieties:
- optical or light;
- electronic;
- laser;
- X-ray;
- scanning probe;
- differential interferon-contrast.
Each is widely used not only in the biological sciences, but also in chemistry, physics, space exploration, genetic engineering, molecular genetics and so on.
History of development of magnifiers
Of course, such a chic variety and perfection of such devices did not come immediately. The most complex structures that allow one to interfere even with wave and corpuscular processes appeared only in the 20th-21st centuries.
The story of the appearance andThe development of devices for magnification has its roots in the mists of time. So, if we talk about magnifiers, the excavations have shown that the Egyptians had the first such devices long before our era. They were made of rock crystal and so skillfully sharpened that they gave magnification up to 1500 times!
Later they began to make glass lenses and examine microscopic objects of interest through them. This continued until the 16th century. Then the great explorer Galileo Galilei designed his first tube, which, when unfolded, resembled a microscope and gave an increase of almost 300 times. This was the progenitor of the modern microscope.
Even later, in the second half of the 17th century, the scientist Tore made small rounded magnifiers. They made it possible to view even at 1500x magnification. A big breakthrough in the development of microscopy was the instruments designed by Anthony van Leeuwenhoek. He produced batches of microscopes that gave enough magnification to see the cellular structure and the world of microorganisms.
Since then, magnifying instruments (loupe, microscope) have become an integral part of almost all types of research, both in biological and other sciences. The modern variety of technical devices owes its existence to people with names such as:
- L. I. Mandelstam.
- D. S. Rozhdestvensky.
- Ernst Abbe.
- R. Richter and others.
Building magnifiers: magnifying glass
From whatWhat are these devices and how do they work? Magnifying devices - a magnifying glass, a microscope - basically have the same structure. The action is based on the use of special glasses - lenses.
Magnifying device magnifying glass is a convex lens, which is framed in a special outer frame - frame. The lens itself is a special optical glass with a double-sided convexity. The frame can be any:
- metal;
- plastic;
- rubber.
Magnifying devices such as loupes allow you to get images at 25x size. Of course, there are different devices according to this indicator. Some magnifiers give a magnification of 2 times, and more modernized and perfect - even 30.
What are magnifiers?
The main use of a magnifying glass is a biology lesson. Magnifying devices of this kind allow you to consider the fine structures of the structure of plants and animals. Different product options may be used.
- A tripod magnifier is a device in which the lens is fixed in a special frame on a tripod for ease of use.
- Device with a handle. With this option, a small convenient handle is built into the frame, with which you can adjust the image quality by zooming in or out of the device.
- Illuminated magnifying glass with built-in compass. This is useful for field research in the forest taiga area. The presence of diode bulbs will allow you to observe even at nightdays.
- Pocket type magnifying glass that folds and closes with a lid. Very convenient option for constant carrying with you.
It is also very common to have combinations between the above: tripod with light, pocket with string or with a handle, and so on.
Microscope - magnifying instrument
What device does this item have? Today, in school classes, only such magnifying devices are used: a magnifying glass, a microscope. We have already de alt with the structure, operation and varieties of the first device. However, for studying deeper processes occurring in cells, examining the bacterial composition of water, and so on, the magnifying power of a magnifying glass is clearly insufficient.
In this case, the main working tool becomes a microscope, most often conventional, light or optical. Consider what structural parts are included in its composition.
- The basis of the whole structure is a tripod. It is a curved element to which all other parts of the device are attached. Its broad base is what supports the entire microscope and keeps it stable in a standing position.
- Mirror, which is attached to the tripod from the bottom of the device. It is necessary to capture sunlight and direct the beam onto the stage. It is fixed on both sides on movable hinges, which facilitates the process of setting the light.
- Subject table - a design fixed on a tripod, most often rounded or rectangular, equipped withmetal fasteners. It is on it that the micropreparation under study is installed, which is clearly fixed on both sides and remains immobile.
- A spotting scope that ends with an eyepiece on one side and lenses of different magnifications on the other. Also securely attached to the tripod.
- Objectives are located immediately above the stage and serve to focus and magnify the image. Most often there are three of them, each can be moved and fixed depending on the need.
- The eyepiece is the top of the telescope, and it is designed to directly observe the object.
- The last important part that all magnifying devices of this kind have is macro and micro screws. They are used to adjust the movement of the telescope in order to set the best image quality.
Obviously, the structure of a microscope is not too complicated. However, this is typical only for optical models. The average magnification that a light microscope is capable of is no more than 300 times.
If we talk about modern designs that give a magnification of thousands of times, then their structure is much more complicated.
What are microscopes and where are they used?
There are different types of microscopes. The simplest of them, light or optical, makes up the bulk of the designs for use by schoolchildren. A magnifying glass and a microscope are the most acceptable magnifying devices. Grade 6 (biology is a school subject in which these lessons are usedobjects) implies familiarity with the device, the principles of operation of these devices.
However, students should be given an idea about the types of microscopes that scientists, physicists, chemists, biologists, astronomers and so on work with. There are 5 main ones, they were listed above. Laser and electronic devices make it possible to obtain images that are hundreds of thousands of times larger than the true size. This allows you to look inside even the smallest particles and make a lot of discoveries in various fields of science and technology.
Microscope preparation
The lesson "The device of magnifying devices" is not the only one in the school course of study that deals with working with such devices. Along with the structure and rules of use, children should lay down the basic knowledge of the preparation of micropreparations for consideration.
The following elements are used for this:
- slide glass;
- cover slip;
- dissecting needle;
- filter paper;
- dropper;
- water.
If you need to examine, for example, the skin of an onion, then you should carefully dissect it with a needle and put it on a glass slide in the form of a thin film. You need to place it in a drop of water pre-formed with a pipette. From above, the preparation is covered with a thin cover glass and pressed firmly. Excess liquid is removed by touching the filter paper. Care must be taken to ensure that there are no air bubbles under the cover slip, otherwise only they will be visible under the microscope.
Factory drugs or fixed
In addition to the production of "live" preparations, ready-made, fixed preparations are often used in schools. They are colored and more informatively saturated, as they are made using special technologies with a high degree of naturalness. According to them, one can master the microstructure of all known structural elements of both animals and plants. In addition, fixed preparations make it possible to study bacteria, microscopic fungi, protozoa and other small creatures.
Studying magnifiers at school
As we noted above, magnifying devices are necessarily studied at school. Grade 6 is the beginning in mastering the principle of operation, the basics of the structure of devices.
It is also during this period that the ability to independently place the preparation on the object table, catch the light and examine the image, achieving high definition in tuning, is laid. At the next stages of education, children already confidently use microscopes and magnifiers for a variety of studies, as they fully master the technique of using devices.
Laboratory work at school using light microscopes
There are actually quite a few of them. Each teacher decides for himself what types of work should be carried out. After all, it all depends on the amount of equipment and its performance. The most common laboratory tests requiring the use of magnifiers are:
- Studying the structure of a plant leaf.
- Study of the process of plant transpiration. The structure of the stomata.
- Mold hyphae.
- Plant spores, their structure.
- Study of the internal composition of the cell and others.
