- #1
Jonsson
- 79
- 0
In general relativity, does momentum conservation mean conservation of 4-momentum or 3-momentum
Last edited:
General relativity is a theory of gravitation developed by Albert Einstein in the early 20th century. It describes how gravity works on a large scale, including the effects of massive objects and the curvature of space and time. Unlike Newtonian physics, which only considers gravity as a force between objects, general relativity explains gravity as a result of the curvature of space and time caused by the presence of matter and energy.
General relativity explains the motion of objects in space through the concept of spacetime curvature. According to this theory, massive objects cause a curvature in the fabric of spacetime, which in turn affects the motion of other objects. This curvature explains why objects follow curved paths in the presence of massive objects, rather than moving in straight lines as predicted by Newtonian physics.
The principle of equivalence states that there is no difference between the effects of gravity and the effects of acceleration. In other words, a person in a closed elevator experiencing acceleration would feel the same as a person standing on the surface of a planet with a gravitational force. This principle is a fundamental concept in general relativity and has been confirmed through numerous experiments.
According to general relativity, time is not absolute and can be affected by the curvature of spacetime. This means that time can pass differently for objects in different gravitational fields. The closer an object is to a massive object, the slower time will pass for it. This phenomenon, known as time dilation, has been confirmed through experiments such as the Hafele-Keating experiment.
Momentum conservation is a fundamental law in physics that states that the total momentum of a closed system remains constant over time. In general relativity, this law still holds true, but the concept of momentum is expanded to include not just linear momentum, but also angular momentum and energy. This means that the total amount of momentum, including all its forms, remains constant in a closed system, even in the presence of gravitational forces.