Does GR imply that space is not empty?

[KennyC]

critical density is the density needed for space to be flat. i was wrong. visible matter is only 5 percent of criticle density. dark matter is 25 percent. that still leaves 70 percent missing. with that exception' date=' my post was correct.

 

 

 

space isn't "nothing" for it can be stretched, compressed, ect. although space and time are relative, spacetime is absolute, which dictates that they are not "nothing."[/quote']

 

Ahhh, but it can't be measured. Only the effects on objects in that space can be seen. It could still be nothing. I makes sense to me there if there is "something" there has to be a coresponding "nothing" at each end of the spectrum.

 

KAC

[ydoaPs]

huh? what can't be measured?

[ydoaPs]

huh? what can't be measured?

[gib65]

So, what I'm getting out of this thread is that we don't know if space is something or nothing, but what we can say for sure is that the effects of gravity can be described as though space were curved.

[gib65]

So, what I'm getting out of this thread is that we don't know if space is something or nothing, but what we can say for sure is that the effects of gravity can be described as though space were curved.

[TrueHeart]

Yeah, it's a morass alright, trying, flailing, fumbling to come up with the right words. Me personally, I will accept that "space" is nothing.. nothing but a construct of the human intellect. Space is no thing and in fact it is defined as the absence of any "thing". What yourdadonapogos said about space can be stretched or compressed -- I'm not buying it for a minute. Ok, so this thread is all about gravitational fields. In Special Relativity we came to accept that motion only pertains relative to physical objects, and not to "space", proper. Now we add gravitation, and it's still the same enchilada: you can know your motion relative to a gravity tensor, but that itself derives from a physical object. The bottom line is that motion is still relative to the physical object and not to 'space' (in my humble opinion).

 

I think it's all word play. The real truth is deeply buried in the math.

[TrueHeart]

Yeah, it's a morass alright, trying, flailing, fumbling to come up with the right words. Me personally, I will accept that "space" is nothing.. nothing but a construct of the human intellect. Space is no thing and in fact it is defined as the absence of any "thing". What yourdadonapogos said about space can be stretched or compressed -- I'm not buying it for a minute. Ok, so this thread is all about gravitational fields. In Special Relativity we came to accept that motion only pertains relative to physical objects, and not to "space", proper. Now we add gravitation, and it's still the same enchilada: you can know your motion relative to a gravity tensor, but that itself derives from a physical object. The bottom line is that motion is still relative to the physical object and not to 'space' (in my humble opinion).

 

I think it's all word play. The real truth is deeply buried in the math.

[astromark]

Its being perdantic. Space is empty. even though we know its not. If you exept that space is such a large place as to be infanite. as I do. Then you could say that space is allmost empty... allmost... If you factor in to this equation all the matter in the universe. The space between the galaxies would be concidered empty. We know its not, but it is, relativly speeking. I do not think you can stretch or askew nothing. It may be posible to distort, shrink, or stretch the spaces between objects, by moving the objects. Not the space between them.

[astromark]

Its being perdantic. Space is empty. even though we know its not. If you exept that space is such a large place as to be infanite. as I do. Then you could say that space is allmost empty... allmost... If you factor in to this equation all the matter in the universe. The space between the galaxies would be concidered empty. We know its not, but it is, relativly speeking. I do not think you can stretch or askew nothing. It may be posible to distort, shrink, or stretch the spaces between objects, by moving the objects. Not the space between them.