Does GR imply that space is not empty?

[gib65]

Since GR says that space-time is curved in the vicinity of matter, does this not mean that there's something there is space? This would be quite different from the classical view of space which is that it's... well... "space" - a big fat field of nothingness. But space-time curvability (is that word?) must mean there's something there to be curved, like the idea of the ether. Is this what modern scientists believe?

 

Gib

[gib65]

Since GR says that space-time is curved in the vicinity of matter, does this not mean that there's something there is space? This would be quite different from the classical view of space which is that it's... well... "space" - a big fat field of nothingness. But space-time curvability (is that word?) must mean there's something there to be curved, like the idea of the ether. Is this what modern scientists believe?

 

Gib

[1veedo]

Space is dynamic. Instead of it being a big playing field, it becomes a filed that plays with everything else.

 

And aether is kindof the opposite. In aether space was a 'background' or median.

[1veedo]

Space is dynamic. Instead of it being a big playing field, it becomes a filed that plays with everything else.

 

And aether is kindof the opposite. In aether space was a 'background' or median.

[gib65]

a[/i']ether is kindof the opposite. In aether space was a 'background' or median.

 

I see what you mean, but this difference is only in the ether being passive and the "warpable" space-time as being active. In either case, there still has to be something there. In order for space to be a dynamic player with all occupying entities, there has to be a player.

[gib65]

a[/i']ether is kindof the opposite. In aether space was a 'background' or median.

 

I see what you mean, but this difference is only in the ether being passive and the "warpable" space-time as being active. In either case, there still has to be something there. In order for space to be a dynamic player with all occupying entities, there has to be a player.

[[Tycho?]]

Do you mean that space must be... something? Because if there is nothing there then what are you warping?

 

Does this bear any resemblance to what you're talking about? I dont really understand what you're asking.

[[Tycho?]]

Do you mean that space must be... something? Because if there is nothing there then what are you warping?

 

Does this bear any resemblance to what you're talking about? I dont really understand what you're asking.

[gib65]

That's exactly what I'm asking.

[gib65]

That's exactly what I'm asking.

[Severian]

Even in Newtonian mechanics, space isn't 'empty'. Implicitly, there is always a 'rule' telling you how to measure distance (the metric). Now, in non-GR mechanics this rule never changes, and is very simple, so there is a tendancy to not think of it as a property of space. But it is! In GR, the presence of mass/energy changes this rule, so that it is not the same everywhere and it then becomes more apparent that it is a property of space. But in principle nothing has changed.

[Severian]

Even in Newtonian mechanics, space isn't 'empty'. Implicitly, there is always a 'rule' telling you how to measure distance (the metric). Now, in non-GR mechanics this rule never changes, and is very simple, so there is a tendancy to not think of it as a property of space. But it is! In GR, the presence of mass/energy changes this rule, so that it is not the same everywhere and it then becomes more apparent that it is a property of space. But in principle nothing has changed.

[[Tycho?]]

That's exactly what I'm asking.

 

Well, space isn't empty, but for other reasons. Even out in intersteller space there is an atom of hydrogen every cubic meter or something like that. Plus no matter where you go there will always be photons moving around. There are also virtual particles that are created then destroyed constantly.

 

These are not the results of GR however. If truely empty space were to exist, I'm pretty sure it would still be curved though, I can't really think of a reason why it wouldn't be.

 

edit: Ok, I thought about this a little more, and I'm going to say I dont know. This is a good question I think, and just because it doesn't seem likely to me doesn't mean its not true. Keep looking and asking and reading, there are people on here with a great deal of knowledge on the subject, I'm sure they'll be able to help you out.

[[Tycho?]]

That's exactly what I'm asking.

 

Well, space isn't empty, but for other reasons. Even out in intersteller space there is an atom of hydrogen every cubic meter or something like that. Plus no matter where you go there will always be photons moving around. There are also virtual particles that are created then destroyed constantly.

 

These are not the results of GR however. If truely empty space were to exist, I'm pretty sure it would still be curved though, I can't really think of a reason why it wouldn't be.

 

edit: Ok, I thought about this a little more, and I'm going to say I dont know. This is a good question I think, and just because it doesn't seem likely to me doesn't mean its not true. Keep looking and asking and reading, there are people on here with a great deal of knowledge on the subject, I'm sure they'll be able to help you out.

[ydoaPs]

'']Well, space isn't empty, but for other reasons. Even out in intersteller space there is an atom of hydrogen every cubic meter or something like that.

 

the critical density is 5 atoms every cubic meter. observations show about 5 percent of that. that means that overall space is curved.

 

our region of space looks flat for the same reason my town(overall) looks flat. it is much smaller than the rest of the universe. in The Fabric of the Cosmos, Brian Greene says that if the universe were shrunk to the size of the Earth, our observable universe would be vastly smaller than a grain of sand. hence, the observed flatness of space.

[ydoaPs]

'']Well, space isn't empty, but for other reasons. Even out in intersteller space there is an atom of hydrogen every cubic meter or something like that.

 

the critical density is 5 atoms every cubic meter. observations show about 5 percent of that. that means that overall space is curved.

 

our region of space looks flat for the same reason my town(overall) looks flat. it is much smaller than the rest of the universe. in The Fabric of the Cosmos, Brian Greene says that if the universe were shrunk to the size of the Earth, our observable universe would be vastly smaller than a grain of sand. hence, the observed flatness of space.

[[Tycho?]]

the critical density is 5 atoms every cubic meter. observations show about 5 percent of that. that means that overall space is curved.

 

our region of space looks flat for the same reason my town(overall) looks flat. it is much smaller than the rest of the universe. in The Fabric of the Cosmos' date=' Brian Greene says that if the universe were shrunk to the size of the Earth, our observable universe would be vastly smaller than a grain of sand. hence, the observed flatness of space.[/quote']

 

 

What is this critical density you speak of? Critical for what?

[[Tycho?]]

the critical density is 5 atoms every cubic meter. observations show about 5 percent of that. that means that overall space is curved.

 

our region of space looks flat for the same reason my town(overall) looks flat. it is much smaller than the rest of the universe. in The Fabric of the Cosmos' date=' Brian Greene says that if the universe were shrunk to the size of the Earth, our observable universe would be vastly smaller than a grain of sand. hence, the observed flatness of space.[/quote']

 

 

What is this critical density you speak of? Critical for what?

[TrueHeart]

I see the point of the original question, and it's a good one. SR demonstrated that "space" is not an entity and hence there is no such thing as a body's unequivocal motion "through space". But then along comes GR and all of a sudden space has properties, and a texture, and a layout. Does that now mean that there IS such a thing as a body's unequivocal motion "through space"??

 

I HONESTLY don't know a correct answer to that inquiry, but can only guess. First off, talk of "curved space" may be merely expeditious terminology, I'm not sure. I'll say, perhaps GR didn't really change anything of invalidating space as a "thing"... because all it did was add gravitational fields that are associated with massive bodies. Those celestial bodies still move about, and the gravitational biases move with them. I'm sure this is outmoded verbiage, but c'est la vie.

 

So in conclusion, nothing is fundamentally changed from SR's negation of "space" as an entity: it is still only the presence of physical bodies that have any causal bearing... take away those landmarks and you're still left with nothing. So space is still a concoction of the human mind, and has no bearing on Physics. Matter has essential bearing and "curved space" is a convenient way of describing the gravitational fields, or tensors, that pervade. 'Not sure.

[TrueHeart]

I see the point of the original question, and it's a good one. SR demonstrated that "space" is not an entity and hence there is no such thing as a body's unequivocal motion "through space". But then along comes GR and all of a sudden space has properties, and a texture, and a layout. Does that now mean that there IS such a thing as a body's unequivocal motion "through space"??

 

I HONESTLY don't know a correct answer to that inquiry, but can only guess. First off, talk of "curved space" may be merely expeditious terminology, I'm not sure. I'll say, perhaps GR didn't really change anything of invalidating space as a "thing"... because all it did was add gravitational fields that are associated with massive bodies. Those celestial bodies still move about, and the gravitational biases move with them. I'm sure this is outmoded verbiage, but c'est la vie.

 

So in conclusion, nothing is fundamentally changed from SR's negation of "space" as an entity: it is still only the presence of physical bodies that have any causal bearing... take away those landmarks and you're still left with nothing. So space is still a concoction of the human mind, and has no bearing on Physics. Matter has essential bearing and "curved space" is a convenient way of describing the gravitational fields, or tensors, that pervade. 'Not sure.

[KennyC]

Since GR says that space-time is curved in the vicinity of matter' date=' does this not mean that there's something there is space? This would be quite different from the classical view of space which is that it's... well... "space" - a big fat field of nothingness. But space-time curvability (is that word?) must mean there's something there to be curved, like the idea of the ether. Is this what modern scientists believe?

 

Gib[/quote']

 

 

It's my understanding that "space" is indeed nothing. Even in intellerspace as someone said there are a few atoms. And yes we can "measure" distance between objects in space, but we can't measure space itself. The reason space is said to be curved or warped is because of the effects of gravity between/on objects. Is that not true?

 

KAC

[KennyC]

Since GR says that space-time is curved in the vicinity of matter' date=' does this not mean that there's something there is space? This would be quite different from the classical view of space which is that it's... well... "space" - a big fat field of nothingness. But space-time curvability (is that word?) must mean there's something there to be curved, like the idea of the ether. Is this what modern scientists believe?

 

Gib[/quote']

 

 

It's my understanding that "space" is indeed nothing. Even in intellerspace as someone said there are a few atoms. And yes we can "measure" distance between objects in space, but we can't measure space itself. The reason space is said to be curved or warped is because of the effects of gravity between/on objects. Is that not true?

 

KAC

[ydoaPs]

'']What is this critical density you speak of? Critical for what?

 

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, my post was correct.

 

It's my understanding that "space" is indeed nothing. Even in intellerspace as someone said there are a few atoms. And yes we can "measure" distance between objects in space, but we can't measure space itself. The reason space is said to be curved or warped is because of the effects of gravity between/on objects. Is that not true?

 

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."

[ydoaPs]

'']What is this critical density you speak of? Critical for what?

 

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, my post was correct.

 

It's my understanding that "space" is indeed nothing. Even in intellerspace as someone said there are a few atoms. And yes we can "measure" distance between objects in space, but we can't measure space itself. The reason space is said to be curved or warped is because of the effects of gravity between/on objects. Is that not true?

 

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."

[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