Einstein's main contributions are the phonograph, the movie camera and the electric light, which have great influence on the world. There are more than 2, inventions and more than 1, patents in his life. Many theories have also been put forward. Such as special relativity, general relativity, light quantum hypothesis, energy conservation, cosmological constant, and so on.
Einstein was born in 1879 in a Jewish family in Ulm, Germany (both parents were Jewish). He graduated from the Federal Institute of Technology in Zurich in 19 and became a Swiss citizen.
Extended information:
1. Photoelectric effect
In p>195, Einstein put forward the photon hypothesis and successfully explained the photoelectric effect, so he won the 1921 Nobel Prize in Physics.
when light irradiates a metal, the electrical properties of the substance change. This kind of photo-electrochromic phenomenon is collectively referred to as the Photoelectric effect.
photoelectric effect can be divided into photoelectron emission, photoconductive effect and photovoltaic effect. The former phenomenon occurs on the surface of an object, also known as external photoelectric effect. The latter two phenomena occur inside the object, which is called internal photoelectric effect.
second, the conservation of energy
E=mc? , the law of the immortality of matter, said the immortality of the quality of matter; The law of conservation of energy is about the conservation of energy of matter.
Although these two great laws have been discovered by people one after another, people think that they are two unrelated laws, each explaining different laws of nature. Some people even think that the law of immortality of matter is a chemical law and the law of conservation of energy is a physical law, which belong to different scientific categories.
Einstein believed that the mass of matter is a measure of inertia and energy is a measure of motion; Energy and mass are not isolated from each other, but are interrelated and inseparable. The change of the mass of an object will change the energy accordingly; And the change of the energy of the object will also change the quality accordingly.
III. Cosmic constant
When Einstein put forward the theory of relativity, he used the cosmological constant (in order to explain the existence of a static universe with non-zero material density, he introduced a term proportional to the metric tensor into the gravitational field equation, which was represented by the symbol λ. This proportional constant is very small and can be ignored in the galactic scale. Only at the cosmic scale can λ be meaningful, so it is called the cosmological constant. The so-called fixed value of anti-gravity) into his equation.
He believes that there is an anti-gravity, which can balance with gravity and make the universe finite and static. When Hubble showed Einstein the astronomical observation results of the expanding universe, Einstein said, "This is the biggest mistake I made in my life."
IV. Relativity
Theory of relativity (English: Theory of Relativity) is a theory about space-time and gravity, which was mainly founded by Einstein, and can be divided into special relativity and general relativity according to different research objects. The introduction of relativity and quantum mechanics has brought revolutionary changes to physics, and they have laid the foundation of modern physics.
The theory of relativity has greatly changed human's "common sense" concept of the universe and nature, and put forward new concepts such as "simultaneous relativity", "four-dimensional space-time" and "curved space-time".
however, in recent years, people have a new understanding of the classification of physical theories-to divide classical and non-classical physics according to whether their theories are deterministic or not, that is, "non-classical = quantum". In this sense, relativity is still a classical theory.
Baidu encyclopedia-Albert Einstein