|Topics covered in this article:|
|Ⅰ. History of Lens|
|Ⅱ. The birth of the magic mirror|
|Ⅲ. Leeuwenhoek and the microscope|
Ⅳ. Robert Hook, the father of British microscopes |
|Ⅴ. The rise of Chase|
|Ⅵ. Calcite and Polarizer|
|Ⅶ. The development of the microscope in the early 20th century|
|Ⅷ. The birth and development of electron microscope|
|Ⅸ. Frequently Asked Questions about Microscope|
A biologist had difficulty analyzing the veins of microscopic plants a long time ago, when there were no optical tools in the globe. The biologist went into the bushes one morning in the summer to observe the state of the plants in the early morning light. He was intoxicated by the life that vomited out fresh leaves, the flowers that were in bloom, the pure rain, and the sun. In the vibrant green sea. He was suddenly drawn to the dew on a little fragile leaf. This section of the leaf surface was magnified as he peered at the leaves through the dewdrops on the green leaves, and the vein pattern was plainly visible. Dewdrops have the effect of enhancing the image, which shocked him. The scientists carried out more tests based on this valuable discovery: by polishing a transparent gemstone into a curved surface to cover the lettering, the writing may be amplified; a glass ball filled with water has the same effect.
The Greek scientist Archimedes (before 287-first 212) was kidnapped by the Roman fleet in his hometown of Sicily, according to the Roman philosopher Seneca (before 4-first 65). When invading, a type of "burning glass" (really a type of lenticular glass ball) was employed to focus sunlight on the enemy ship's sails, causing the sails to absorb a large amount of sunlight, heat up, and burn. The Roman fleet was destroyed after the ships were burned.
The employment of lenses to create fire is, of course, not unusual. Children stare on the sun through their grandparents' reading glasses, which can ignite the confetti in their hands; torches used in large-scale sporting events around the world also use curved metal or curved glass mirrors to collect fire. Glass, on the other hand, was an extremely uncommon substance in ancient times, and making glass balls with high transparency was much more difficult.
Pliny, a Roman scholar, told an intriguing anecdote in his book "Natural History" more than 1900 years ago: a Roman Empire ship was loaded with soda (sodium carbonate). A hurricane sprang up one day as the ship was travelling in the ocean, forcing the ship to anchor in the bay. The crew went ashore to prepare burners for cooking and burning garments. Surprisingly, there isn't a single stone on the long beach; it's just quartz sand. To prepare the pot for cooking, what do you use? Everyone began to transfer the soda blocks and place them on the beach as pot stones after a sailor suddenly remembered that there were a lot of soda blocks on the boat that looked like stones. The rice pot is ready to cook, and the firewood sticks have been lighted. The rice had been cooked, the cloths had been dried, and everyone had eaten. When the crew returned to the ship after a short break, a miracle occurred: there were some shiny beads in the ashes—this is the world's first glass ball. On the beach, it is made by heating quartz sand (silica) and soda (sodium carbonate).
Although the Romans utilized magnifying lenses around 2000 years ago, glass lenses were invented in the 13th century, according to studies.
However, most early glass spheres were not clear enough, were dark in color, and were not spherical enough. A French geologist discovered a tomb buried in a cave on the Rivi Mountain in the 18th century, where an Egyptian queen was buried more than 3,400 years ago. The tomb has a large number of burial artifacts. The neck of the young woman is the most interesting. A dark green string of glass beads hangs from the ceiling; it is varied in shape, usually oval, and not particularly reflective.
Scientists believe that the raw ingredients were not pure enough, and there were too many impurities, thus crystal clear, colorless, and spherical glass beads could not be burned because the glass was fired at a temperature that did not exceed the criteria at the time. Rough lenses have been discovered on the European islands of Klee and Asia Minor. Their dates of birth may be traced back to the year 2000 BC.
When the British scholar Robert Grossetest (1175-1253) and his disciple Roger Bacon (1220—1292) observed the light flowing through the glass ball in the 13th century, they had no idea what happened to it. The only thing they discovered was that the object had been zoomed in.Bacon has since employed a lens to magnify the text on the page to aid his reading.
Italians began wearing spectacles around 1300 years ago. Biconvex lenses were used in the earliest spectacles. It has the ability to amplify items and is very beneficial to the elderly. Later, mankind created double-concave mirrors, which have two concave inward surfaces, thick borders, and a thin center. The thing appears to shrink as a result of it. This type of lens can aid in the correction of myopia (ie myopia glasses).
Glass making has been a significant business since the 16th century. Mirrors, masterfully created, have become a veritable kingdom of glasses production, particularly in Holland, the hometown of the inventor of the telescope, Hans.
Charles Jensen (1580-1683), a Dutch eyeglasses producer, was a great glass lens expert in the second half of the 16th century. He's not only brilliant at grinding lenses, but he's also good at analyzing how they're used.
Jensen compound microscope
He accidentally overlapped two separate lenses in 1590. When he adjusted the distance between the two lenses, he noticed that the thing had been greatly magnified. At the time, it was considered a miracle, and it was dubbed the "magic mirror." Jensen put the two lenses into two iron barrels of various calibers, resulting in a large and tiny iron barrel that fit together. To alter the distance between the lenses, the little iron barrel may be slid into the huge iron barrel. To enclose the two iron barrels, a third, larger iron barrel was used—this is the first form of the "compound microscope."
This groundbreaking microscope is still on display at the East Rand Science Museum in the Netherlands.
Jensen developed a more beautiful "magic mirror" in 1605, using gold-plated copper as the sleeve and casting the squatting figure of the dolphin with raw copper as the bracket adornment, and making a more exquisite "magic mirror" that can magnify the item. The first "magic mirror" was mostly used for insect observation. The fleas' claws changed into sharp claws like monsters, and even the small hairs became as thick as a rope while they were under the "magic mirror."
In 1610, Galileo utilized the "magic mirror" to examine the physiology of insects. The "magic mirror," also known as the "light mirror," is roughly 20 years older than the telescope (born in 1610). However, in 1625, it was given the formal name "Microscope" and was called from Italy. What makes people so uninterested in this instrument? Because it did not make big scientific discoveries as rapidly as the telescope after it was released. People are still unaware of its purpose and function. Between invention and popular use, there is a significant period of time.
A teacher observed a drop of sewage with a Jensen microscope one day and made a new finding that had never been seen before. He spotted a lot of "alive" things in the water, doing different activities. Normally, these things are not apparent to the human eye. These "small things" that have been identified are bacteria and germs that everyone is familiar with.
Later, researchers established that certain compounds, such as fermentation, winemaking, and medications, are extremely important to humans. They are inextricably linked to them, but they will continue to create human calamities such as food spoilage, infectious infections, and even human and animal deaths.
Since then, humans have widened their views, realizing that, in addition to the familiar world of everyday existence, there are vast celestial worlds in the universe, as well as a microscopic world that has to be recognized and revealed to humanity.
Seruti was the first to publish his microscope studies of several bees in 1625. His descriptions of bee shape and structure in his book are far more extensive than those previously documented by beekeeping specialists and biologists. This has sparked a lot of interest in academics, and it's become clear how important microscopes are in scientific research. It has a great effect.
The microscope's research and development accelerated in the second half of the seventeenth century, and it was gradually used to biology and medicine studies.
Fuck (1635-1703), a British scientist, improved the microscope in 1665, used it to view plant cells and insects, and published his book "Micrographs" in 1666. He included beautiful photographs of observations of nettle leaves, lice anatomy, and insect eyes in the book. For the first time, he described the honeycomb-shaped "cells" seen in cork (oak bark) and other plant tissues as "cells." This is the first proof that humans have figured out how cells work.
The glomerulus and the lymphatic mass of the spleen were discovered in the same year by Italian anatomist Malpigi, who invented a better microscope to examine sections of the kidney and spleen.
The Fuck microscope is a delicate instrument. A simple objective lens and an eyepiece lens are located at both ends of the finely adorned lens barrel. A candle or an alcohol lamp serves as the source of illumination. This microscope has a magnification of 30-40 times and has demonstrated a certain level of technological perfection. The discovery of cells by ordinary people taught biologists that all living things are made up of cells. As a result, individuals began to investigate the structure and functioning of various cells in order to gain a better grasp of the microcosm's mysteries. People progressively discovered the origin of disease with the use of optical microscopes and discovered that plague, cholera, dysentery, diphtheria, leprosy, and even skin boils are all caused by bacteria. People are dedicated to developing techniques to deal with these murders when they are discovered, dramatically improving human abilities to prevent and treat diseases, and saving the lives of tens of thousands of people.
Optical microscopes are also widely employed in industry, agriculture, science, and education, and have evolved into a powerful instrument for humans to comprehend and modify nature. The secret of iron and steel, for example. Under a microscope, iron is made up of pure white iron particles, but steel is made up of two different forms of iron particles and carbon particles, i.e., an iron-carbon composite. It can be seen that microscopes can be used to analyze the composition of metals in a scientific way.
Leeuwenhoek (1632-1723) was born in the Dutch city of Delft. He comes from an impoverished household when he was a child. He began as an apprentice at the age of 16 and six years later founded his own tiny shop. He has no formal schooling, but he has always been industrious and studious, adept at watching and researching things, and fascinated by nature since he was a child. He learned how to build lenses out of glass when he was younger.
He began making microscopes in 1675 and utilized them to explore and observe the microscopic world.
Leeuwenhoek released his paper on the results of his lifetime research and creation of microscopes in 1704, when he was 72 years old.
In his lifetime, he produced 247 microscopes and 172 lenses, according to statistics: He has contributed to the development and development of microscopes by equipping a laboratory with 26 microscopic instruments for the Royal Dutch Society.
Single-chip microscope invented by Leeuwenhoek
Leeuwenhoek's contribution to the invention of the microscope was not only his ability to grind a range of high-quality lenses, but also his methodical development of the compact microscope with a large curvature. This microscope is made up of two copper or silver plates that are closely linked. Between the apertures of the two metal plates, a tiny lens with a large curvature is fitted. The lens has a focal length of less than 1 mm. When viewing, place the object on the needle's tip; the needle's tip employs two spirals to adjust the focus, and the eyes are close to the light to observe. Although it appears to be simple, it has a magnification of 240-280 times and can identify delicate objects as small as 1/700 mm.
None of the microscopes made by others in the 17th and 18th centuries could compare to it. Leeuwenhoek utilized his microscope to investigate a variety of topics and make significant discoveries. For example, in 1668, he used a microscope to confirm the finding of capillaries in Malbiki, Italy.
In 1674, he noticed the oval red blood cells of fish, frogs, birds, as well as human and other animal red blood cells.
He discovered a protozoan parasitic in a frog's viscera in 1675, which shocked the biological world at the time.
In 1677, he published a description of Hamley's animal sperm, confirming the importance of sperm in embryonic development.
He discovered microbes in 1683. He removed tartar from an elderly man's teeth and examined it under a microscope. He discovered that some germs were matchsticks, some were little balls, and still, others had fluffs on the sides and continued to swim around.
His discovery drew a lot of attention. Many people, including the Queen of the Netherlands, want to examine the new world of microorganisms via his microscope to feast their eyes.
People from the same era as Leeuwenhoek, such as Malbiki (1628-1694) in Italy and Gru (1628-1712) in England, had their own originality in microscope development techniques.
However, in the more than 100 years since Leeuwenhoek's discovery, microscope research has made little progress. Chromatic aberration affects both microscopes and telescopes. It started off as a colorless flake under the microscope, but as time went on, other colors developed, making it difficult for humans to observe those tiny things precisely and even causing some misunderstandings.
Klingen Stirren (1698-1765), a Swedish physicist, produced a lens with no chromatic aberration soon after, although it never reached the level of practical application.
In 1757, British mathematician Dorland (1706—1761) refined and corrected the curvature of each lens on the microscope using the spherical aberration calculation method described by mathematician Hall in 1722, and created the first A microscope with practically no chromatic aberration.
Then there's Robert, who is known as the "Father of British Microscopes." Robert, Hooker duplicated Leeuwenhoek's microscope and validated Leeuwenhoek's finding of small organisms in water droplets. Hooke is most known for discovering the law of elasticity of elastic materials, which he improved upon Leeuwenhoek's microscope according to his own design.
Robert Hooker's microscope
Robert was born in 1655. Boyle was invited to Oxford University to do scientific research, and he became Boyle's assistant. In 1665, Robert Hooker published the book "Microscope," in which he coined the term "cell."
Robert Hook had a major argument with Newton, the great scientific master of the day, about the nature of light. Light, according to Newton, is a particle, while according to Robert, it is a wave. Light, according to Hook, is a wave. Although Robert. Hooker's daring to oppose the authority of science was suppressed as a result of Newton's outstanding position in science history, Robert. Hooker's courage to challenge the authority of science is still admirable.
The main task of optical experts at the time was to solve the problem of chromatic aberration in microscopes.
Italian optics scientists Enmisi and Cefalie created chromatic aberration-free microscopes in 1816 and 1824, but the low magnification did not draw attention.
Hileiden, a German botanist, used a microscope to find fresh plant cells in 1838. Shiwan, a German zoologist, discovered new animal cells in the second year, laying the groundwork for the creation of biology and medicine.
In the mid-nineteenth century, Zeiss, an average worker at the University of Jena's Department of Mechanical Engineering, noticed a high need for microscopes in scientific research, production departments, schools, and hospitals, and he became interested in making microscopes. In 1846, he dropped out of Jena University to acquire funding for a tiny factory in Leipzig specializing in microscope manufacturing. Later, Abbe, a physics professor at the University of Jena, and Dr. Schott, a university glass technician, joined forces and founded the Chase firm.
Because Chase understands mechanics, the professor of physics understands optics, and the glass technicians can polish lenses, the three of them collaborate to make the microscope manufacturing firm success, and the scale is growing by the day. Since then, Chase microscopes have gained a reputation for high quality, good effects, and a wide range of functions, and they have opened up new markets all over the world. It is still one of the world's most well-known optical instrument manufacturers.
The resolution limit theory on Abbe and his monument.
During his time at Chase, physics professor Abbe made significant contributions to the construction of microscope lenses. In 1878, he created the first oil immersion objective lens with a numerical aperture greater than 1.0, and in 1883, he created an apochromatic objective lens capable of correcting three colors, substantially improving the microscope's resolution capability and contributing to biology and medicine. The most recent round of significant findings. People have, for example, observed cell division (asexual reproduction) under a microscope, clarified that sexual reproduction is the union of male and female nuclei, and discovered that the nucleus is the foundation of genetic material.
The first microscope was invented in 1590, and it has been around for over 400 years. Microscopes are improving in quality, and there are more and more types available. The following primary types can be found in this family: Microscope alone: Its optical system is relatively simple, consisting of one or more simple lenses, and the magnification is minimal. The most basic microscope is a magnifying mirror. Commonly used magnifying mirrors include three-legged magnifying mirrors, folding pocket magnifying mirrors, eye mask magnifying mirrors, and portable magnifying mirrors.
Initially, three-legged and eye-shielding magnifying mirrors were mostly used for sketching images and repairing clocks, while folding and hand-held magnifying mirrors were primarily used for observation of biological, mineralogical, and petrological specimens, as well as for seeing photographs.
A small magnifying mirror attached on a fountain pen has been introduced in Japan that can magnify minute substances and structures 50 times. It is lightweight and resistant to harm. An ordinary optical microscope is a compound microscope. It's mostly utilized to study cells, germs, microbial structures, tissues, and components, among other things. It has the ability to enlarge human live cells by more than 200 times.
Electron microscopes, biological microscopes, full-phase microscopes, petrographic microscopes, polarized light microscopes and measurement, tool microscopes, and so on are also available.
In Northern Europe, Iceland is a popular tourist destination. It's a little volcanic lava island with black volcanic boulders strewn about. Many minerals, including the popular agate and the crystal clear Calcite, can be found in these lavas. A tourist boat arrived in Iceland again in the summer of 1830 on a lovely day, and tourists stepped ashore to play. A blond-haired boy noticed a colorless, transparent stone on the ground that appeared like glass and picked it up to play with it. However, he dropped the stone on the ground and it fractured into many pieces. When his parents saw the broken stones, they were taken aback. These shards turned out to be all rhombuses of the same shape, but they were all various sizes. They curiously scooped up the rubble and stuffed it into their pockets. When they returned to their home in the evening, the kid was ecstatic to see the crystal clean little rubble. He suddenly sprang up and yelled, "Dad, look., One word has become two words, it's crazy!" as he covered a small piece of rubble in newspaper.
His father was astounded when he saw it! This father is meticulous and has a basic understanding of optics. He drew a dot on the white paper with a pen, then covered the black dot with the transparent ore, and found that one black dot had changed into two black dots. One black dot remained in situ as the ore was spun, but the other black dot moved. The black dot spins around the dot. As a result, he came to the conclusion that this mineral is optically valuable. This mineral was given the name Calcite since it was discovered in Iceland. In truth, calcium carbonate is the chemical makeup of this ore, which is found all over the world. This crystalline, translucent, and full crystal is known as Icelandic in mineralogy, and its common name is calcite.
Calcite is not only crystal clear and beautiful, but it also has the above-mentioned unique features, making it ideal for optical instrument manufacturing. Through it, observe one point or a line on the paper, and it will become two points or two lines. The effect is known as "birefringence" in optics. Because of the varied optical properties of the mineral in each direction, when a beam of light penetrates the crystal, it is decomposed into two rays with different qualities. Calcite may be used to make polarizing microscopes, rotatory sugar meters, photometers, polarizing prisms in movie cameras, large-screen displays, chemical analysis colorimeters, and astronomical telescopes thanks to its birefringence and polarization qualities.
Nicol (1768—1851), a British physicist, employed Calcitein a famous optical experiment in 1841. He cut the iceberg stone into a rectangle, then cut it diagonally, grinded the sliced surface into a very level and flat surface, and used a beam of light to glue the two cut parts together. Into this bonded and cut crystal. It was discovered that when light penetrates the crystal, it produces two beams of light (birefringence). One of two light rays passing through the gum passes through, while the other fails to pass and refracts. The light traveling through was also polarized, changing its original character.
This experiment is crucial because it provides the theoretical foundation for building a polarizing microscope. Later, Nicol used the microscope to turn Calciteinto a prism, based on the results of the experiment. It was originally known as the Nicol prism, but it has since been renamed the polarizer. On the basis of ordinary microscopes, the upper and lower polarizers are installed to create the polarizing microscope. To make a polarizing microscope, a lower polarizer is inserted under the stage, an upper polarizer is installed on the lens barrel, and a condenser lens is added. Minerals and rocks are commonly observed with a polarized light microscope. Mineral and rock specimens are ground into very thin slices by geologists (about 0.03 mm thick). When light passes through the slices, the material composition and structural properties can be discerned.
Polarizing microscopes come in a variety of shapes and sizes, but their essential architecture are all the same. Suzhou Optical Instrument Factory's domestically produced XPA type polarizing microscope. The Leitz-type polarizing microscope from Germany is a polarizing microscope with a long history and excellent optical performance.
Schade, Adolf, an Austrian-Hungarian chemist, died in 1903. Richard Adolf Zsigmondy (Richard Adolf Zsigmondy) created the super microscope, which is used to see particles in gas or colloids and is based on light scattering rather than reflection. It was given the term Super by Sigmundi because it can investigate objects with scales smaller than the wavelength. The term "super" refers to something that is beyond the wavelength's limit. In 1925, he was awarded the Nobel Prize in Chemistry. In 1897, Sigmundi joined the SCHOTT glass plant, which was founded by Abbe and Schott Glaswerke AG. Sigmundi studied brown glass and invented a glass while working in the factory. "Jenaer Milchglas" is the name given to this glass.Sigmundi quit in 1890 to work with Carl Zeiss on the development of a slit ultramicroscope. In the glass, Sigmundi was able to identify 4nm particles. He started at the University of Göttingen in 1907 and rose through the ranks to become a professor of organic chemistry before retiring in February 1929. Siegmundi's greatest contribution was laying the groundwork for contemporary colloidal chemistry.
Fritz was born in the year 1932. Sernik (FritsZernike) won the Nobel Prize in Physics in 1953 for inventing the phase-contrast microscope, which allows scientists to investigate colorless and transparent biological materials without having to stain them. The phase-contrast microscope, on the other hand, did not garner enough attention when it was originally invented. Sernik and Zeiss had talked about collaborating, but Zeiss was not interested. It wasn't until Sernik was apprehended by the Nazis during World War II, and media accounts brought Sernik back to prominence, that the phase contrast microscope was given significant consideration.
Polarization microscopy is another non-marking technique invented by German physicist Mark Berek (Mark Berek) before WWII, though the exact date is unknown. Although individuals began to use fluorescence microscopes at that time, the subcellular structure detected by fluorescence microscopes is highly contentious because the samples of fluorescence microscopes must be fixed and stained. Many individuals believe that the structure visible by non-labeled microscopes is an artifact created by dyes. It's easier to get noticed. The fibrous structure of the spindle was seen by W.J.Schmid in 1937, however, the image was a little blurry. Shinya Inoué confirmed Schmid's discovery in 1953 with a self-made enhanced polarization microscope. The results of the two were similar when compared to the results of the fluorescence microscope, which aided in the development of the fluorescent microscope to some extent.
The differential interference contrast was devised by Georges Nomarski in the 1950s and can be used to analyze non-stained living biological material. Thick or pigmented samples cannot be studied with a differential interference contrast microscope because the refractive index of the transparent sample must match the medium environment of the sample, but the resolution of the differential interference contrast microscope can be better than that of the phase-contrast microscope under the right conditions. higher. Allen developed Video-enhanced Contrast, Differential Interference Contrast (AVEC-DIC) microscopy in 1981, combining video camera technology with a differential interference contrast microscope. The camera can, of course, be used in conjunction with the polarization microscope to provide Video-enhanced Contrast Polarization Microscopy.
Fluorescence resonance energy transfer, or FRET, was discovered by Theodor Fster in 1940. Foster confirmed that electron excitation energy may be transmitted from donor fluorescence to acceptor chromophore, and that the efficiency of the transfer is proportional to the reciprocal of the molecular distance. In vivo protein interactions can be studied using a FRET microscope. Taekjip Ha, a Korean scholar, was the first to achieve single-molecule FRET in 1996. Single-molecule FRET may now be used to examine molecular interactions and dynamics in vitro in real-time.
Abbe (1840-1905), a German optics scientist, highlighted the topic of optical microscope resolving power limits as early as 1874. He pointed out that using an optical microscope to study the structure of materials smaller than 0.2 microns is clearly pointless. The optical microscope's highest magnification is 5000 times. Because of its limited distinguishing capacity, it has not been able to enter into the mysterious microcosm, despite broadening people's horizons and playing a significant role in specific disciplines.
Trying to lower the wavelength of the light or replacing the light with an electron beam is one technique to increase the resolution of a microscope. Moving electrons have wave qualities, according to De Broglie's theory of matter waves, and the quicker the speed, the shorter the "wavelength." It is feasible to utilize an electron beam to magnify an object if the speed of the electrons can be boosted high enough to focus the electron beam with a magnetic field.
Knorr and Ruska of Germany modified a high-voltage oscilloscope with a cold cathode discharge electron source and three electron lenses in 1931, and got a magnified image of more than 10 times, proving that an electron microscope could magnify images.
After Ruska's improvements, the electron microscope's resolving power reached 50 nanometers in 1932, which was nearly ten times that of the optical microscope at the time, and the electron microscope began to attract attention.
The American Hill employed a disperser to overcome the negative effects of the asymmetry of the electron lens rotation in the 1940s, and produced a new advance in the electron microscope's resolving power, gradually reaching the level of the present electron microscope.
The early stages of electron microscope development coincided with the period when the creation of New China was a waste of time. With amazing insight, our country's scientific professionals followed the global trend in scientific research. They succeeded in creating a transmission electron microscope with a resolution of 3 nanometers in 1958. In 1979, it was remade. A large transmission electron microscope with 0.3 nanometer resolution.
The electron microscope is not suited for detecting a single molecule at this time because the resolution is too poor and the electron beam destroys the sample too much. In the 1980s, scanning tunneling microscopes and atomic force microscopes made it possible to see individual atoms or molecules on the surface for the first time.
The first scanning electron microscope (SEM) was created by British engineer Charles Oatley in 1952, and it is regarded one of the most important technologies of the twentieth century. The electron microscope has revealed many items that were previously undetectable to the naked eye, such as viruses.
Although replacing light with electrons is an unusual concept, there are other technologies that are even more startling.
The scanning tunneling microscope was conceived in 1983 by two IBM Zurich scientists, Gerd Binnig and Heinrich Rohrer (STM). This microscope is much more radical than the electron microscope in that it completely abandons the usual microscope paradigm. The "tunneling effect" is the working principle of a scanning tunneling microscope. The tunnel scanning microscope does not have a lens and instead relies on a probe. When a voltage is introduced between the probe and the object, the tunneling effect occurs if the probe is very close to the object's surface—on the order of nanometers. The electrons generate a weak current as they flow across the space between the item and the probe. This current will alter in proportion to the distance between the probe and the item. By measuring the current, we can determine the form of the object's surface, and the resolution can be as fine as a single atom. Binnig and Rohrer earned the Nobel Prize in Physics in 1986 for their great discovery, and Ruska, the creator of the electron microscope, shared the Nobel Prize in Physics with them in the same year.
The use of electron microscopes in cell biology helped to provide the groundwork for current cell biology. The electron microscope is used to visualize the ultrastructure of numerous cells.
The advancement of electron microscopy peaked in the second part of the twentieth century. For example, in 1995, the Romanian-born American cell biologist George Emil Palade used electron microscopy to uncover ribosomes. Ribosomes are the protein translation factories in cells. Parad was given the Nobel Prize in Medicine in 1974 for his discovery, which made a significant contribution to our understanding of cell activity. If a worker wants to do his job successfully, he must first sharpen his tools, and Parad's contribution is thanks to the electron microscope. Although the electron microscope's resolving power is significantly greater than that of an optical microscope, it is difficult to see living creatures since the electron microscope operates in vacuum, and electron beam irradiation can destroy biological material.
Due to the evident drawbacks of the electron microscope, even if its resolution is higher, it will never be able to replace the optical microscope, and optical microscopy research will continue in silence.
1. Who invented the microscope?
The earliest microscope was invented by a spectacle maker named Jason.
2. When was the microscope invented?
Invented around 1590.
3. What is a microscope?
It is used to magnify tiny objects into instruments that can be seen by human eyes. Microscopy spectroscopy and electron microscopes.
4. How to use a microscope?
First, take the lens and place it
Hold the mirror arm with your right hand and hold the mirror holder with your left hand.
Place the microscope on the bench, slightly to the left (the microscope is placed about 7 cm from the edge of the bench). Install the eyepiece and objective lens.
Second, on the light
Rotate the converter to align the low-power objective lens with the light hole (the front end of the objective lens and the stage should be kept at a distance of 2 cm).
Align a larger aperture at the light hole. Look into the eyepiece with your left eye (open your right eye for easy drawing at the same time later). Rotate the reflector to reflect the light into the lens barrel through the light hole. Through the eyepiece, you can see the bright white field of vision.
Put the glass slide specimen to be observed (it can also be made of a thin paper sheet printed with "6") on the stage and press it with the press clamp, the specimen should be directly facing the center of the light hole.
Rotate the coarse collimation screw to slowly lower the lens barrel until the objective lens is close to the slide specimen (look at the objective lens to prevent the objective lens from touching the slide specimen).
Look into the eyepiece with your left eye, and at the same time turn the coarse collimation screw in the opposite direction, so that the lens barrel slowly rises until the object image is clearly seen. Turn the fine focus screw slightly to make the image of the object more clearly.
After the experiment, wipe the surface of the microscope clean. Rotate the converter, shift the two objective lenses to the sides, slowly lower the lens barrel to the lowest point, and place the reflector vertically. Finally, put the microscope into the mirror box and return it to its original place.
5. Why is a specimen smaller than 200 nm not visible with a light microscope?
The highest resolution of the human eye is 0.2mm
If the magnification of the optical microscope is 1000, the image will be imaginary, and the objective lens will determine the image quality.
So after synthesis, the resolution of the optical microscope is up to 200nm