He is known as "the last man who knows everything", but this is not enough to describe him, because he is not only a man who knows everything, he is also a man who knows everything.
Here he is: Thomas Young!
Thomas Young (1773-1829), English physicist and physician
Thomas Young's contribution to physiological optics
Starting in 1792, Thomas Young studied medicine at the University of London, the University of Edinburgh and the University of Göttingen, and obtained his MD at the age of 23.
One day, Thomas Young was looking at something and had a question about how the eye could see clearly. Based on his knowledge of microscopy and the dissection of a cow's eye, Thomas Young discovered a muscle structure near the lens. Further research revealed that the muscle contracted to change the curvature of the lens.
By 1793, when Thomas Young was 20 years old, he explained for the first time in a systematic and complete way how the human eye could see in his article "Observations on Sight". At the same time, Thomas Young also explained the cause of astigmatism.
The principle of how the eye sees 
Later, Young first proposed the "three primary colors principle," which is the theory that all colors can be formed by using the superposition of the three optical primary colors (RGB): red, green, and blue (indigo). This principle became the basis of modern color theory. Later, Thomas Young's obsession with optics continued to grow, drifting away from medicine.
The three primary colors of light 
Thomas Young's contribution to optics
On the nature of light, Thomas Young disagreed with Sir Isaac Newton, a scientific authority at the time. His familiarity with optics and acoustics led Young to firmly believe that "light is not a particle" and that it has similar fluctuations to those of sound.
In 1801, inspired by the phenomenon of interference in water waves, Thomas Young successfully demonstrated the phenomenon of light interference through the famous Young's double-slit interference experiment, and explained the phenomenon of light diffraction on the basis of interference. Nowadays, the concept of "half-wave loss", which is commonly used in our physics books, was also proposed by Yang. The concept of "half-wave loss", which is now commonly used in our physics books, was also introduced by Yang.
Thomas Yang boldly challenged Newton's conclusion about the "particle theory" of light, and laid the foundation for the comeback of fluctuation optics. However, Thomas Young's conclusions were still not accepted by the public at that time, which led him to divert his energy again.
Double-slit interference 
Thomas Young's contribution to mechanics
First of all, one word: Young's modulus. Yes, this Young, too, is Thomas Young. This theory was proposed by Thomas Young in the second volume of his Lectures on Natural Philosophy and Mechanical Technique, published in 1807.
For a columnar material of length L and cross-section S, when it elongates ΔL due to the force F, F/S is called stress, the physical meaning of which is the force per unit cross-sectional area of the wire; ΔL/L is called strain, the physical meaning of which is the elongation per unit length of the wire. The ratio of stress to strain is called the modulus of elasticity.
Of these, Young's modulus is one of the most common moduli of elasticity, which is based on Hooke's law. It characterizes the physical properties of a material and its magnitude signifies the stiffness of the material: the higher the Young's modulus, the less likely it is to deform.
In fact, the quantitative relationship between interfacial tension and contact angle was systematically described by Thomas Young as early as 1805 when he was studying wetting and capillary phenomena, also known as the Thomas Young equation. However, the mechanical interpretation of Young's equation has been controversial due to various reasons. It was not explained by our scholars until 2020.
Young's modulus 
Thomas Young's contribution to linguistics
By the age of 13, Thomas Young could already read Latin, Greek, French and Italian. Before the age of 20, he expanded his linguistic frontiers to the East again and began to work on Hebrew, Arabic, Persian, etc.
In 1813, Thomas Young devoted himself to the decipherment of the Rosetta Stone. The Rosetta Stone was an ancient Egyptian tablet found by the French army in a small town in Egypt during the Napoleonic era, on which the same story was recorded in three languages, ancient Egyptian hieroglyphics, ancient Egyptian cursive script, and ancient Greek, and was the key to deciphering the ancient Egyptian text.
Although, because of the problem of reference materials, Thomas Young eventually failed to decipher it, his research provided inspiration for the French linguistic genius Jean François Champollion (1970-1832), who was enlightened to decipher this ancient script and laid the foundation for the study of Egyptology.
Although Champollion insists that this was the result of his own research, there are claims that Thomas Young is also credited with this honor.
The Rosetta Stone (now in the British Museum)
Written at the end
Optics, mechanics, mathematics, medicine, astronomy, geophysics, linguistics, zoology, archaeology, history of science, etc., as well as vocal music and painting, and even acrobatics like tightrope walking, seemingly unrelated skills, but all played out simultaneously in Thomas Young's case.
His footprints covered areas that only we can't think of, and nothing he couldn't walk. Although Thomas Young died at the age of 56, his life renders a set of encyclopedias.
admire | Source: WeChat emoji package "Red Lips Daily"
 Baidu Encyclopedia. Thomas Young.
 Andrew R. Sudden Genius: The Gradual Path to Creative Breakthroughs[ M].Oxford university, 2010.
 Robinson A. The story of writing[J]. Story of Writing, 2007.
 https://www.sohu.com/a/197467655_ 208051
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