Quote:
Originally Posted by xelasnave
"how does mass distort time and space?  ..... there must be a machinery in real terms.. an interaction of particles perhaps?..a communication of "waves" between masses...it is an interesting question ..the very one avoided by Newton and Dr A. 
Or how does the force of gravity (remembering GR does not speak of a force) get from one place to another...
Neither Newton or DrA speaks of how the force may work  ... |
Hi Alex,
The first part you raise is the issue. In metric theories of gravity (the class of theories to which the General Theory of Relativity belongs) matter/energy is put in by hand. GR is not a theory of matter. This is what quantum theory is all about.
It is important to understand that in GR space and time do not have an independant existance. It is the "spacetime" that is warped by the presence of matter/energy as per the Einstein equation.
It is the warping of the spacetime that causes bodies (like the Earth) to appear to follow a curved path. All bodies are actually following a straight line in a curved spacetime geometry.
In this way Eisteins theory explains the action of gravity at a distance (unlike Newton's theory). What GR doesn't explain is the mechanism by which matter causes the spacetime to curve. This is what quantum gravity is all about.
The first fairly comprehensive theory of matter that we humans have developed (quantum theory) doesn't include gravitational effects. It is played out in the flat spacetime of special relativity.
Have fun,
Doug