Einstein’s full name is Albert Einstein. He was born in Germany and is a famous physicist. He laid the theoretical foundation for nuclear energy development and ushered in a new era of modern science and technology. He is recognized as the greatest physicist since Galileo and Newton.
His main achievements include the theory of relativity, the photoelectric effect, conservation of energy (E=mc^2) and the cosmological constant.
1. In 1905, after Einstein published the first article on the special theory of relativity (i.e., "On the Electrodynamics of Moving Bodies"), it inspired many scientists who were in a confused stage at that time and provided them with A new door was opened, and among the more famous scientists was Planck. So far he has received help from Planck and has made better progress in the theory of relativity. It was not until 1916 that the theoretical research reached a relatively mature stage. He published a new paper "The Foundation of General Relativity" and pointed out in the paper: The theory of relativity that was previously applicable to inertial systems was called special relativity, and it was only applicable to inertial systems. The principle that the laws of physics are equally valid is called the principle of special relativity, and further expresses the principle of general relativity: the laws of physics must be true for any frame of reference that is moving in any way.
2. In 1905, Einstein proposed the photon hypothesis and successfully explained the photoelectric effect, thus winning the 1921 Nobel Prize in Physics. The photoelectric effect refers to the photoelectric phenomenon in which light irradiates metal and causes changes in the electrical properties of the material. In fact, Hertz discovered the photoelectric effect in 1887, and it was Einstein who was the first to successfully explain the photoelectric effect.
3. In the special theory of relativity, Einstein proposed the famous mass-energy formula: E=mc^2 (E represents energy, m represents the original mass, and c represents the speed of light). He 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 interconnected and inseparable. Changes in the mass of an object will cause corresponding changes in energy; changes in the energy of an object will also cause corresponding changes in mass.
4. The cosmological constant is a concept proposed by Einstein when he was studying the special theory of relativity. In order to explain the existence of a static universe with non-zero matter density, he introduced a metric tensor into the gravitational field equation. The term of proportion is represented by the symbol Λ. This proportionality constant is so small that it is negligible on the scale of the Milky Way. Only at the scale of the universe, Λ may be meaningful, so it is called the cosmological constant. The cosmological constant is still a mystery that scientists are talking about even now.