Motion also cuve space then special theory of relativety should be same as general theory of relativety?

Question

mass curves space and hi speed particles also then both theory is same whats the different between the two .

why not gravity is repulsive?

Answer 1

The difference between the two is that general relativity can deal with curved spacetime.  Special relativity can only deal with flat spacetime.  (So morningfox isn't quite right: Special relativity is not restricted to objects moving at constant velocity.)  Spacetime is curved in the vicinity of any object with mass, so special relativity, strictly speaking, is valid only where there is no mass around.  In other words, it's never actually *exactly* valid.

However, puny objects like the Earth or even the Sun curve spacetime so little that it takes fairly sensitive instruments to detect the curvature, so special relativity--and Newtonian mechanics, too--work very well here.  It takes very massive objects, like black holes, for the difference to be really noticeable.

To answer your other question, gravity between two ordinary masses is not repulsive because mass always produces positive curvature.  (That's a rather substantial simplification, but I'm not sure how I could put it without equations.)

EDIT: I'm afraid I can't understand your follow-up.  But the main point is that general relativity can deal with gravity, and special relativity explicitly cannot.  The fact that high-speed particles curve space (so do low-speed particles, for that matter) is not relevant to the difference in theory, because special relativity ignores the gravitational aspect of the masses of moving objects.

The only way to introduce gravity into special relativity is to treat it as an external force, a la Newton.  This only works reasonably accurately for weak gravitational fields and slow-moving objects; as soon as the fields become very strong, or the objects in "orbit" move really fast, you must resort to the more correct general relativity formulation.  For instance, both general relativity and Newtonian gravity (embedded in a special relativity context) predict that light will be deflected by a gravitational field (such as the Sun's).  But general relativity predicts twice the deflection that Newtonian gravity does, and experiments have shown that it is general relativity that is correct.

Answer 2

The special theory deals only with objects that are moving with constant speed.  The general theory includes acceleration.

Science is not very good at answering "why" questions.  It works mostly with "what", "when", and "how".  "Why" is left as a topic for religion.

Answer 3

High speed particles undergo an apparent time-dilation due the relative speed of their inertial reference frame with respect to ours.  But they don't curve space-time in the same way (or on the same scale) as larger masses.  The fact that they -do- have mass (and therefore -do- curve space-time on a quantum scale) has led to a lot of theorizing about 'quantum gravity' and speculation that we might manage to someday unify Quantum Mechanics and General Relativity.

Doug

Answer 4

1. Acceleration gives objects curved world-lines. But motion does not curve space-time.

2.Dark matter halos might very well be repulsive and explain the red shifts of galaxies.

Special, large-scale, cosmological, expanding space is NOT adequate as a theory.

Answer 5

High speed particles don't curve space.  I'm not sure where you're getting that from.  Gravity is an attractive force because it can be pictured as you said - curving the space around an object.  This doesn't work the other way.