Euclid himself has always been an unsolved secret. No one knows his date of birth, date of death and birthplace. The only certainty is that he worked in Alexandria during the reign of Ptolemy I Soter (305 BC-285 BC). According to some indirect records, it is speculated that Euclid may have been educated in Athens in his early years and studied and worked in Plato's college, so he was familiar with Greek mathematics.
Two stories in ancient books illustrate Euclid's attitude towards learning. There is a story: One day, King Ptolemy asked Euclid if there were any other shortcuts to learning geometry besides his Elements of Geometry. Euclid replied, "There is no king in geometry." It means that in geometry, there is no road specially paved for kings. This sentence was later extended to "there is no royal road to knowledge" and became a proverb that has been passed down through the ages. Another story says: A student just started to learn the third geometry proposition and asked what he would gain after learning geometry. Euclid said, "Give him three coins and let him go, because he just wants to gain strength in his study." From these two stories recorded in ancient books, it can be seen that Euclid advocated that learning must be gradual and diligent, and disapproved of the style of opportunism and quick success.
Euclid was an outstanding scientist, who marked the transformation of the science center from Athens to Alexandria. Euclid's name is inseparable from geometry, because he wrote a geometry textbook, The Elements of Geometry, which is still the authoritative work of geometry, and of course it has been revised. After the invention of printing, more than 1000 editions have been published. "I studied Euclid" and "I studied geometry" are synonymous, not long ago. Therefore, Euclid is the most successful and immortal author of geometry textbooks. However, Euclid's fame as a mathematician is not due to his own research results. In his book, only a few theorems were created by himself. What he did also made him a great mathematician. He used the mathematical knowledge accumulated since Thales' time to sort out and systematize the labor achievements of two and a half centuries and compiled a book. At the beginning of writing this book, he introduced a series of admirable simple and exquisite axioms and formulas. Then he arranged the theorems one by one, which was very logical and hardly needed improvement.
The only theorem that has always been recognized as Euclid himself is his proof of Pythagoras theorem. Although his masterpiece mainly involves geometry, it also raises the questions of ratio and proportion, as well as the well-known number theory. It was Euclid who proved that prime numbers are infinite. He also proved that the square root of 2 is irrational through a series of simple arguments that have not been improved so far. He also regarded light as a straight line, thus making optics a part of geometry. Of course, Euclid did not generalize all Greek mathematics, even all Greek geometry. After him, Greek mathematics was vigorous for a long time, and people like Apolloni and Archimedes all added a lot of wealth to mathematics.
Later outstanding scientific figures such as Copernicus, Kepler, Galileo and Newton all accepted Euclid's tradition. They all studied Euclid's Elements of Geometry seriously and took it as the basis of their mathematical knowledge. Euclid's influence on Newton was particularly obvious. Newton's Principles of Mathematics was written in the form of "geometry" similar to "Elements of Geometry". Since then, many western scientists have followed Euclid's example and explained how their conclusions were drawn from the original assumptions. Many mathematicians, such as Bertrand Russell, alfred whitehead, and some philosophers, such as Spinoza, are also the same.
Besides the Elements of Geometry, Euclid has many works, such as Known Numbers, Segmentation of Figures, Error Correction Sets, Canon Lines of Conic Curves, Trajectory of Curved Surfaces, Observational Astronomy, etc. Unfortunately, most of them have been lost. However, after two years of historical test, the geometric elements are still the most influential.