Albert Einstein was born on March 14, 1879, in the city of Ulm in southwest Germany. He moved to Munich with his family a year later. When Einstein was in elementary school and middle school, his homework was ordinary. Because he behaves slowly and doesn't like to interact with others, his teachers and classmates don't like him. In 1900, Einstein graduated from the Technical University of Zurich. Due to his lack of enthusiasm for certain subjects and his indifference to teachers, he was refused a stay in school. Unable to find a job, he made a living as a tutor and substitute teacher. At the age of sixteen, he applied for the Engineering Department of the Federal University of Technology in Zurich, Switzerland, but failed the entrance examination. He accepted the advice of Professor Weber, the president of the Federal University of Technology and the school's famous physicist, and completed high school courses at the state high school in Aarau, Switzerland, to obtain a high school diploma. On February 21, 1902, Einstein obtained Swiss citizenship and moved to Bern, waiting for recruitment by the Patent Office. On June 23, 1902, Einstein was officially employed by the Patent Office as a third-level technician. His job responsibilities were to review various technological inventions and creations applying for patent rights. In 1903, he married his college classmate Mileva Marik.
From 1900 to 1904, Einstein wrote a paper every year and published it in the German Journal of Physics. The first two articles were about the thermodynamics of liquid surfaces and electrolysis, in an attempt to provide a mechanical basis for chemistry. Later, I found that this path was unavailable, and I turned to the study of the mechanical basis of thermodynamics. In 1901, some basic theories of statistical mechanics were proposed, and three papers from 1902 to 1904 all belonged to this field.
The 1904 paper carefully explored the fluctuations predicted by statistical mechanics and found that energy fluctuations depended on the Boltzmann constant. It not only applied this result to mechanical systems and thermal phenomena, but also boldly applied it to radiation phenomena to derive the formula for the fluctuation of radiant energy, thereby deriving Wien's displacement law. The study of fluctuation phenomena enabled him to make major breakthroughs in radiation theory and molecular kinetic theory in 1905.
In 1905, Einstein created an unprecedented miracle in the history of science. He wrote six papers this year. In the six months from March to September, he used his spare time after working eight hours a day at the Patent Office to make four epoch-making contributions in three fields. He published Four important papers were published on the quantum theory of light, molecular size determination, Brownian motion theory and special relativity.
In March 1905, Einstein sent the paper he believed to be correct to the editorial office of the German "Annals of Physics". He shyly said to the editor: "I would be very happy if you could find space in your annual report to publish this paper for me." The paper he was "embarrassed" to send was called "About Light" A Speculative View of Generation and Transformation”.
This paper extends the quantum concept proposed by Planck in 1900 to the propagation of light in space and proposes the light quantum hypothesis. It is believed that: for time averages, light behaves as fluctuations; for instantaneous values, light behaves as particles. This is the first time in history that the unity of wave nature and particle nature of microscopic objects is revealed, that is, wave-particle duality. In 1921, Einstein won the Nobel Prize in Physics for his "discovery of the law of the photoelectric effect."
Three years later, French physicist Perrin confirmed Einstein's theoretical predictions with sophisticated experiments. This irreproachably proved the objective existence of atoms and molecules. This led Ostwald, the German chemist who most firmly opposed atomic theory and the founder of energeticism, to proactively declare in 1908: "The atomic hypothesis has become a fundamental and solid foundation." scientific theory".
In June 1905, Einstein completed a long paper "On the Electrodynamics of Moving Bodies" that ushered in a new era of physics, and fully proposed the special theory of relativity. This is the result of Einstein's 10 years of brewing and exploration. It has largely solved the crisis of classical physics that emerged at the end of the 19th century, changed the concept of space and time in Newtonian mechanics, revealed the equivalence of matter and energy, and created the A brand new world of physics is the greatest revolution in the field of modern physics.
In September 1905, Einstein wrote a short article "Is the inertia of an object related to the energy it contains?" ", as a corollary of the theory of relativity. Mass-energy equivalence is the theoretical basis of nuclear physics and particle physics, and also opened the way for the release and utilization of nuclear energy realized in the 1940s.
After the establishment of the special theory of relativity, Einstein was not satisfied and tried to extend the application scope of the principle of relativity to non-inertial systems. He found a breakthrough from the ancient experimental fact that all objects in the gravitational field have the same acceleration discovered by Galileo, and proposed the equivalence principle in 1907.
In this year, his university teacher and famous geometer Minkovsky proposed the four-dimensional space representation of special relativity, which provided a useful mathematical tool for the further development of the theory of relativity. Unfortunately, Einstein was Didn't realize its value.
Einstein considered the discovery of the equivalence principle to be the most enjoyable thought in his life, but his subsequent work was very difficult and took a lot of detours. In 1911, he analyzed a rigid rotating disk and realized that Euclidean geometry was not strictly valid in gravitational fields. At the same time, it was also discovered that the Lorenz change is not universal, and the equivalence principle is only valid for infinitesimal areas... At this time, Einstein already had the idea of ??general relativity, but he still lacked the mathematical foundation necessary to establish it.
In 1912, Einstein returned to work at his alma mater in Zurich. With the help of Grossmann, his classmate and professor of mathematics at his alma mater, he found the mathematical tools to establish the general theory of relativity in Riemannian geometry and tensor analysis. After a year of hard cooperation, they published the important paper "Outline of General Relativity and Theory of Gravity" in 1913, proposing the metric field theory of gravity. This is the first time that gravity and metrics have been combined to give Riemannian geometry real physical meaning.
However, the gravitational field equation they obtained at that time was only covariant for linear transformations, and did not yet have covariance under any coordinate transformation required by the principle of general relativity. This is because Einstein was not familiar with tensor operations at the time and mistakenly believed that as long as he adhered to the law of conservation, he had to limit the choice of coordinate systems. In order to maintain causality, he had to give up the requirement of universal covariance.
The three years from 1915 to 1917 were the second peak of Einstein’s scientific achievements. Similar to 1905, he also achieved historic achievements in three different fields. . In addition to the final completion of the general theory of relativity in 1915, which is recognized as one of the greatest achievements in the history of human thought, the theory of gravitational waves in terms of radiation quantum was proposed in 1916, and modern cosmology was created in 1917.
In the 30 years from 1925 to 1955, apart from the completeness of quantum mechanics, gravitational waves and the motion problems of general relativity, Einstein devoted almost all of his scientific and creative energy to The search for unified field theory.
In 1937, with the cooperation of two assistants, he derived the equations of motion from the gravitational field equations of general relativity, further revealing the unity between space, time, matter, and motion. This is the generalized theory of The major development of the theory of relativity was also the last major achievement achieved by Einstein in his scientific creation activities.
In terms of the same theory, he never succeeded. He never got discouraged and started from the beginning with full confidence every time. Because he stayed away from the mainstream of physics research at that time and attacked problems on his own that were unsolvable at the time, he was very isolated in the physics community in his later years, contrary to his situation in the 1920s. However, he remained fearless and unswervingly followed the path he had identified. Until the day before his death, he was still preparing to continue his mathematical calculations on the unified field theory in his hospital bed.