Can space be bent "selectively"?

Question

In Einstein's theory of relativity, he talks about gravity bending space so that objects are pulled towards other massive objects.

If a force like gravity "bends" space, then would it be likely that a force like electrical charge would also "bend" space? After all, they are both "forces" and they both work on other objects at distance. They also both have strengths related to the inverse of the distance from the object creating the force.

However, an electric charge doesn't effect everything around it in the same way that gravity does. The electric charge only attracts or repels other charged objects. So, how could the electric force be bending space? Could it just be "bending" space for some objects but not others?

It seems like, in my opinion, that if you want to be able to find a link between the two forces, you would need to get rid of the "bending of space" idea. Have people working on the "Grand Unified Theory" come up with any ideas on this subject?

Answer 1

The reason the "bent space" idea works for gravity, has to do with the fact that gravity causes all objects, regardless of their mass, to accelerate at the same rate. Einstein showed that any force that acts that way can be described just as well by interpreting the force as a curvature of space. It's a mathematical thing.

Other kinds of force fields, like electrical fields, don't behave that way; they don't accelerate different masses at the same rate. So the "bent space" interpretation won't work for such forces. Those forces are (currently) explained in terms of particles being passed back and forth, carrying momentum from one place to another.

People working on a unified theory are definitely looking to see if momentum-carrying particles ("gravitons") can be used to explain gravity as well. But so far none have been found.

Answer 2

Your basic premise is incorrect in several ways.

Einstein talked and wrote of the curvature of SPACETIME, and NOT of space alone. What is more, he showed that Newtonian gravity was due ENTIRELY to the "time-bending" aspect rather than the "space-curving" aspect. (The notion of "space-bending" is far more visually compellling, and is the main reason why Einstein's understanding of gravity is so seriously misrepresented in popular accounts.) "Space-bending" only comes into the picture in very strong field or highly relativistic situations.

Einstein also removed the concept of "pulling" from his gravitational vocabulary; if anything replaced it, it was the notion of geodesically "coasting" in a curved spacetime.

Live long and prosper.

Answer 3

To unify then every object must be charged, according to the theory that you just stated.

The question is how do you spread the charge..so that it can be unified...

There is no straight answer to that question...