What is a microscope?
Probably, each of us, at least once in our life, had the opportunity to work with such a device as a microscope - who is at school in a biology class, and someone, perhaps because of his profession. With the help of a microscope, we can observe the smallest living organisms, particles. A microscope is quite a complex device, and besides, it has a long history, which will be useful to know. Let's see what a microscope is?
The word "microscope" comes from two Greek words "micros" - "small", "skopeo" - "look". That is, the purpose of this device is to examine small objects. If a more precise definition is given, then a microscope is an optical device (with one or several lenses) used to obtain enlarged images of certain objects that are not visible to the naked eye.
For example, microscopes used in today's schools can increase 300-600 times, this is quite enough to see the living cell in detail - you can see the walls of the cell itself, vacuoles, its core, etc.But for all this, he went a long way of discovery, and even disappointment.
The history of the discovery of the microscope
The exact time of the discovery of the microscope has not yet been established, since the very first devices for observing small objects were found by archaeologists in different eras. They looked like a regular magnifying glass, that is, it was a biconvex lens, giving an increase in the image several times. I’ll clarify that the very first lenses were made not of glass, but of a certain transparent stone, so there’s no need to talk about image quality.
Later microscopes consisting of two lenses were already invented. The first lens is the lens, it turned to the object under study, and the second lens is the eyepiece at which the observer looked. But the image of objects was all the same strongly distorted, due to strong spherical and chromatic deviations - the light was refracted unevenly, and because of this the picture was fuzzy and colored with color. But still, even then the magnification of the microscope was several hundred times, which is quite a lot.
The lens system in microscopes was significantly complicated only at the very beginning of the 19th century, thanks to the work of physicists such as Amici, Fraunhofer, and others.In the lens device has already been used a complex system consisting of collecting and scattering lenses. Moreover, these lenses were from different types of glass that compensated for the shortcomings of each other.
The microscope of a scientist from Holland, Leeuwenhoek had an object table, where all the studied objects were folded, and there was also a screw that allowed this table to move smoothly. Then a mirror was added - for better illumination of objects.
There are simple and complex microscopes. A simple microscope is a single lens system, just like a magnifying glass. The complex microscope combines two simple lenses.
A complex microscope, respectively, gives a greater magnification, and besides, it has a higher resolution. It is the presence of this ability (resolving) makes it possible to distinguish the details of the samples. An enlarged image, where not to discern the details, will give us some useful information.
Sophisticated microscopes have two-stage schemes. One lens system (lens) is brought close to the object — it, in turn, creates an authorized and magnified image of the object.Then, the image is already enlarged by another lens system (eyepiece), it is placed, directly, closer to the eye of the observer. These 2 lens systems are located at opposite ends of the microscope tube.
Modern microscopes can produce a huge increase - up to 1500-2000 times, while the image quality will be excellent. Binocular microscopes are also quite popular, they split into two images from one lens, and you can look at it with two eyes at once (with two eyepieces). This makes it possible to distinguish even more visually fine details. Such microscopes are usually used in different laboratories (including medical ones) for research.
Electronic microscopes help us to “view” the images of individual atoms. True, the word “consider” is applied here relatively, because we don’t look directly with our eyes - an image of an object appears due to the most complex computer processing of the received data. The device of a microscope (electronic) is based on physical principles, as well as the method of “palpating” the surfaces of objects with the thinnest needle, whose tip is only 1 atom thick.
Nowadays, during the development of digital technologies, each person can purchase a lens attachment on the camera of his mobile phone, and take photos of any microscopic objects. There is also a very powerful USB-microscopes, when connected to a home computer, allowing to view the resulting image on the monitor. Most digital cameras are capable of taking pictures in macro mode, with the help of it you can take photos of the smallest objects. And if you put a small collecting lens in front of the lens of your camera, you can easily get an increase in photos up to 500 times.
Today, new technologies help to see what literally a hundred years ago was not available. Parts of the microscope throughout its history have been constantly improved, and now we see the microscope already in the finished version. Although scientific progress does not stand still, and in the near future, perhaps even more advanced models of microscopes will appear.