The development of human science and technology is always accompanied by chance and opportunity, and so is the emergence of one of the greatest inventions in human history - the microscope.
About 4,000 years ago, the ancient Egyptians refined glass from sand, however, they only took it to make glass jewelry and did not own the optical application aspect. The earliest magnifying glasses appeared around the 7th century B.C., and it was discovered that they could be used to light items for fire with the help of sunlight, but the magnification of these magnifying glasses was quite limited.
The study of the refraction of light began in the 2nd century A.D. by Ptolemy, a Greek in Egypt - yes, the same Ptolemy who proposed the heliocentric theory of astronomy. In his optical work "Optics", the refraction of light is discussed in detail. However, a microscope that could be used as a microscope had still not been invented at this time.
By the 13th century, the Italians began to use lenses to correct vision, and eyeglasses began to appear. It took a few more centuries, and in the late 16th century, two Dutchmen each independently discovered a way to make microscopes.
Like many great inventions, the discovery of microscopy in the first place was so serendipitous that the son of a Dutch eyeglasses merchant, Jensen, was fiddling one day with two convex lenses that his father had given him as a toy, when to his sudden amazement he realized that a huge, clear image appeared in front of his eyes ......
About twenty years later, the great Galileo, a pioneer of modern science, began to use microscopes for scientific research - to look at the compound eyes of insects.
But the man who really brought people into the microscopic world was Levonhuk, who, I don't know whether to say he was a different kind of person or a return to the basics, started out not with the recently invented double-lens magnification technique but with single-lens microscopy. He used his spare time to develop a set of unique grinding technology, grinding a piece of only 3mm in diameter spherical lens, magnification reached 200 times, and from then on to open the door to the microscopic world.
He was the first to discover microorganisms in the rainwater on the ground, and then realized that there were no microorganisms in the rainwater that did not fall to the ground. He went on to improve the microscope, devising a variety of microscopic techniques to increase the magnification to 300 times. He became the first person to truly discover the microscopic world, the first to discover cells, the first to discover sperm ......
What happened afterward is known to everyone, the microscope in the field of medicine, people in the microscope found bacteria, human medicine officially stepped into the era of modern medicine. The level of human medical care has increased dramatically, but that is already 200 years later ......
So the microscope deserves to be the greatest invention of mankind!
Optical microscope due to the diffraction of light, in the visible wavelength of magnification is a limit, in the visible light range, the limit of magnification of about 1600 times, about the minimum can distinguish 0.3 microns. With the continuous development of science and technology, more non-optical microscopic techniques appear, such as electron microscopy, scanning tunneling microscope, etc., and now the resolution of scanning tunneling microscope has reached the nanometer level, and can distinguish a single layer of atomic arrangement.
In addition to the more and more high-end atmosphere, recently there is also a super fun microscope - can be attached to the cell phone to use the microscope. According to the official data given, the optical resolution limit of this little bitty cell phone microscope is 1 micron (one thousandth of a millimeter), and taking into account the image capture capability of the phone, the actual resolution is about 2 microns.