Does space move? What is space?

[k9b4]

Does space move? What is space?

 

[phinds]

Whether or not it is appropriate to say that space "bends / expands / curves" and so forth is a somewhat contentious issue. Basically, the math says that space-time is a framework in which things happen and does not itself matter. It "bends" in that geodesics near large bodies are not straight in the Euclidian sense. It "expands" in the sense that things get farther apart. Google "metric expansion" for further discussion.

 

[k9b4]

It "expands" in the sense that things get farther apart.

Can't we just say that the objects are moving away from each other, through space, and the space itself is not moving?

 

[mfb]

Can't we just say that the objects are moving away from each other, through space, and the space itself is not moving?

For objects far away, this is not consistent with observations.

 

[k9b4]

For objects far away, this is not consistent with observations.

But hang on, what do you mean it's not consistent with observations? How can you observe space moving? You can only observe relative motion, as dalespam pointed out in my other thread in this subforum.

 

[mfb]

But hang on, what do you mean it's not consistent with observations?

In the same way the hypothesis "there is no sun" is not consistent, just with more math involved.

How can you observe space moving? You can only observe relative motion, as dalespam pointed out in my other thread in this subforum.

Right, but there is no model that can reproduce the observed redshifts with objects moving in space.