Microscopy: The history and evolution of microscopes

The invention of the microscope has completely changed the way man sees the world. Microscopy enabled the observation and exploration of several areas previously unknown, revolutionizing scientific knowledge.

What until then was invisible to the naked eye started to be analyzed through the microscope lenses. Theories like “spontaneous generation” (in which living organisms can originate from inanimate matter) have been overthrown.

The “invisible beings”, which caused several diseases in the population, often attributed to the supernatural, started to be observed. It was learned about the diseases and the microscopic creatures that originated it. This enabled the evolution in the treatment and functioning of diseases.

The word microscope has its origin in the terms mikrós (from the Greek, small) and scoppéoo (from the Greek to observe, to see through). Many still argue about who invented this equipment. But to reach the form we know today, it took a long process, which started with something simple, the lenses.

LEARN A LITTLE ABOUT THE HISTORY OF THE MICROSCOPE:

Invention of lenses – the base of the microscope

Since 721 BC there have been reports of a crystal, known as the Layard lens , which was cut, polished and had magnifying properties. The use of magnifying glasses goes back to several ancient peoples.

The Nimrud Lens / The Layard Lens- http://www.britishmuseum.org

The Romans already wore biconvex lenses. Nero, according to reports, watched gladiatorial battles with the help of a carved emerald. Which leads one to suppose that the properties of myopia correction lenses were known to some extent. However, lenses became really known and used around 1280 in Italy, with the invention of glasses.

The first microscope

During the 1590s, two Dutch eyeglass makers, Zacharias Jansen and his father Hans, started experimenting with lenses. They put several lenses in a tube and made an important discovery. The object near the end of the tube appeared to be very magnified, larger than any single magnifying glass could reach. At first it was treated like a toy by European royalty.

Although ordinary magnifying glasses are basically a simple microscope, when we talk about the invention of the microscope, we refer to the “compound microscope”.

Composite microscopes feature two or more lenses, connected by a cylinder. The upper lens, which the person looks at, is called the eyepiece. The lower lens, close to the object, is known as the objective lens. So today, when we say “microscope”, we are talking about the compound microscope.

MICROSCOPY: THE MICROSCOPE AND SCIENCE

The first consequences of this discovery for the sciences came mainly from the Englishman Robert Hooke and the Dutchman Anton Van Leeuwenhoek .

In 1665, scientist Hooke wrote a book with detailed drawings of his microscopic discoveries, called Micrographia.

His most significant observations were made on fleas and cork. He observed the fleas under a microscope and was able to observe hair on his body. In the cork he saw pores. Hooke was the first to use the term cell when describing a structure filled with empty honeycomb-like honeycombs. He named each cell cell (in English), or “cell”, comparing the pores of cork to the cells of the monks.

Hooke’s drawing about his observation that led to the term “cell”.

Leeuwenhoek produced his own lenses, with a much greater magnifying power than the microscopes of the time. With his microscope, for the first time it was possible to see and document the presence of microscopic beings. In 1675, he was the first to see and describe bacteria, red blood cells and life in a drop of water.

The quality of the lenses that Leeuwenhoek produced, promoted a magnification ranging from 40x to 160x. One of his microscopes provided a 280x magnification.

The evolution of microscopy

Over the years, many changes have been made and the quality of microscopes has greatly increased. The improvements, mainly in the lenses, solved several of the optical problems.

In mid-1880, optical microscopes reached a resolution of 0.2 micrometers (equivalent to a millionth of a meter), a limit that remains today.

In 1933, Ernst Ruska invented the first electron microscope. This equipment has a much higher resolution power. Unlike an optical microscope that uses light, the electron microscope uses an electron beam and electromagnetic lenses to observe the object, reaching magnification up to one million times. The importance of the equipment was so great that in 1986, Ruska received the Nobel Prize in Physics.

Microscopy: Timeline

0721

721 BC – Layard lens, one of the first lenses created.

1280

Invention of glasses

1665

Robert Hooke publishes the book Micrographia. The term cell is used for the first time.

1675

Anton van Leeuwenhoek improves lenses, being the first to observe bacteria.

1830

Joseph Jackson Lister reduces the problem with spherical aberration. When the lenses were placed at precise distances from each other, they provided good magnification without blurring the image.

1878

Ernst Abbe formulates a mathematical theory correlating resolution to the wavelength of light.

1903

Richard Zsigmondy develops the ultramicroscope and is able to study objects below the wavelength of light.

1932

Frits Zernike invents the phase contrast microscope that allows the study of colorless and transparent biological materials.

1933

Ernst Ruska develops the electron microscope. The ability to use electrons in microscopy greatly improves resolution and expands the frontiers of exploration.

1981

Gerd Binnig and Heinrich Rohrer invented the scanning tunneling microscope that provides three-dimensional images of objects at the atomic level.

 

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