Einstein vs Newton: Exploring Gravity & Spacetime

[aaron35510]

If gravity is a force, then the moment the object producing gravity is taken away, it should result in gravity taken away instantaneously.
However, why does Einstein say that Newton's classical mechanics are incorrect and that in fact he decided to propose spacetime and not follow what Newton has claimed hundreds of years ago?

 

[michelcolman]

Gravity travels at the speed of light. If you take the object producing gravity away, you stop feeling its gravity as soon as you stop seeing it. I don't see any reason why a force would need to act instantaneously. In quantum mechanics, for example, forces are transmitted by special kinds of particles, which travel at the speed of light.

Einstein said Newton's laws were incorrect because they didn't perfectly fit into his theory, which seemed more elegant. His own results explained gravity in a different way which felt more consistent. It turns out he was right, because GR explains the perihelion shift of Mercury, curvature of light (double the Newtonian value), time dilation in gravitational fields (measured in experiments) and quite a few other things.

 

[Entropia]

While Newton's classical mechanics may have accurately described the behavior of gravity in his time, Einstein's theory of general relativity provides a more comprehensive and accurate understanding of gravity. According to general relativity, gravity is not a force between objects, but rather a curvature of spacetime caused by the presence of mass and energy. This means that the moment an object with mass is removed, the curvature of spacetime will still exist and continue to affect the motion of other objects. This is why gravity does not disappear instantaneously when an object is removed.

Einstein's theory also explains phenomena that cannot be explained by Newton's laws, such as the bending of light around massive objects and the existence of black holes. Additionally, general relativity has been extensively tested and confirmed through various experiments and observations.

It is important to note that Einstein did not reject Newton's laws entirely. In fact, they are still applicable in many situations and are a crucial foundation for our understanding of physics. However, in order to fully explain the behavior of gravity, Einstein's theory of general relativity is necessary.

In conclusion, while Newton's classical mechanics were groundbreaking in their time, Einstein's theory of general relativity provides a more accurate and comprehensive understanding of gravity and spacetime. It is a testament to the progress and advancement of science that theories can be improved upon and refined over time.