Joke Collection Website - Cold jokes - Einstein - Theory of Relativity - Introduction - What are the stories?

Einstein - Theory of Relativity - Introduction - What are the stories?

The theory of relativity is the basic theory about space-time and gravity. It was mainly founded by Einstein and is divided into special relativity (special relativity) and general relativity (general relativity). The basic assumptions of the theory of relativity are the principle of constant speed of light, the principle of relativity and the principle of equivalence. Relativity and quantum mechanics are the two basic pillars of modern physics. Classical mechanics, which lays the foundation for classical physics, is not suitable for high-speed moving objects and objects under microscopic conditions. Relativity solves the problem of high-speed motion; quantum mechanics solves the problem under microscopic subatomic conditions. The theory of relativity has greatly changed mankind's "common sense" concepts about the universe and nature, and proposed brand-new concepts such as "simultaneous relativity", "four-dimensional space-time" and "curved space".

Special Theory of Relativity

Main article: Special Theory of Relativity

Special Theory of Relativity is a theory of relativity that is limited to discussing inertial systems. Newton's view of space and time holds that space is a three-dimensional space that is flat, isotropic and isotropic at every point, and time is a single dimension independent of space (and therefore absolute). Special relativity believes that space and time are not independent of each other, but a unified four-dimensional space-time whole, and there is no absolute space and time. In the special theory of relativity, the entire space-time is still flat, isotropic and isotropic at every point. This is an ideal situation corresponding to the "global inertial system". The special theory of relativity takes the speed of light in vacuum to be constant as a basic assumption. Combining the principle of special relativity with the above-mentioned properties of space and time, the Lorentz transformation can be derived.

General Theory of Relativity

Main article: General Theory of Relativity

General Theory of Relativity is a theory published by Albert Einstein in 1915. Einstein proposed the "equivalence principle" that gravity and inertial forces are equivalent. This principle is based on the equivalence of gravitational mass and inertial mass (current experiments have confirmed that within an accuracy range of 10?6?112, there is still no difference between gravitational mass and inertial mass). According to the equivalence principle, Einstein extended the special principle of relativity to the general principle of relativity, that is, the form of physical laws is unchanged in all reference systems. The equation of motion of an object is the geodesic equation in that reference frame. The geodesic equation has nothing to do with the inherent properties of the object itself, but only depends on the local geometric properties of space and time. Gravity is the manifestation of the local geometric properties of space-time. The existence of material mass will cause the curvature of space and time. In the curved space and time, objects still move along the shortest distance (that is, move along the geodesic line - in Euclidean space, it is a straight line movement). For example, the earth moves in a straight line in the sun. The geodesic motion in the curved space-time actually revolves around the sun, causing gravitational effects. Just like on the curved surface of the earth, if you move in a straight line, you actually go around a great circle on the surface of the earth.

Basic principles of special relativity

Matters are in eternal motion in interactions. There is no matter that does not move, and there is no motion without matter. Since matter is interconnected and interacts with each other, Therefore, the movement must be described in the interrelationship of substances, and it is impossible to describe the movement in isolation. In other words, movement must have a reference object, and this reference object is the reference system.