First, I believe you are confusing the concepts of "space" and "spacetime". To be honest I have seen times where even those who know the difference use the words in a confusing manner, but generally they are speaking to others who understand...
The use of the two statements by Rajesh, was and is just a "red herring" raised to confuse even more the confusing picture of spacetime curvature that he has.
origin reputation and knowledge is known by most reputable members and although his phrase may not have been perfect, in this instant, it was raised for the reasons I have stated.
It is difficult to separate descriptions of spacetime curvature from gravitation, but that does not really mean that either one causes the other. You can think of the two as the same thing, in different words.., and still not know the fundamental why of, or how gravitation emerges from the presence of mass.
We certainly do not know the how and why of gravity, but just as certainly, we do know that gravity exhibits its presence when spacetime warps/curves in the presence of mass/energy.
Like all scientific models, the object is to describe what we see, and the question of reality remains open.
They are both abstract concepts, relative to everyday experience. It has really only been since the developement of high precision clocks and things like the GPS system that we have any practical examples of time dilation, what I believe you are referring to as time distortion... And we still have no direct evidence of length contraction. These two together play a large role in what is usually meant by curvature of spacetime, though spacetime cuvature gets even more complicated and involved than just time dilation and length contraction.
I disagree strongly.
Firstly space and time which has come to be known as spacetime with the advent of relativity, are terms that are interchangible and I see nothing wrong or confusing in doing that.
Secondly spacetime, is real and as I have mentioned, has been measured with GP-B.
I also see time dilation and length contraction as real and dispute your inference that we have no evidence for length contraction, common sense and logic tells a different story.
In any experiment with two FoR's and the speed of light, if both frames happen to disagree on time, then it must be inevitable that they also disagree on lengths, to both parties to agree to the fact that the speed of light is constant.
Although Sean only talks of the reality of time in the following link, it is reasonable to extrapolate that to the fact that space, spacetime are also real.
http://www.preposterousuniverse.com/blog/2013/10/18/is-time-real/