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marcus

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## Main Question or Discussion Point

Something Einstein wrote in 1952 contains this quote

"Space-time does not claim existence on its own, but only as a structural quality of the field."

It is not especially easy to grasp the meaning, I suspect, but it might be worth thinking about. Eh quoted this in another PF thread and I was able to find an online reference in this Usenet post, which gives more context:

> However, I consider the ultimate words of Einstein on this matter

> to be the fifth appendix, added in 1952 (three years before his

> death), to the fifteenth edition of his book "Relativity: The

> Special and the General Theory." In that appendix, titled

> "Relativity and the Problem of Space," Einstein explicitly

> addresses the issue in question here. (Note that in the following

> "type (1)" space is Minkowski space.)>

> "If we imagine the gravitational field, i.e., the

> functions g_ik, to be removed, there does not remain a

> space of the type (I), but absolutely _nothing_, and

> also no 'topological space'. For the functions g_ik

> describe not only the field, but at the same time also

> the topological and and metrical structural properties

> of the manifold. A space of type (I), judged from the

> standpoint of the general theory of relativity, is not

> a space without field, but a special case of the g_ik

> field, for which -- for the coordinate system used,

> which in itself has no objective significance -- the

> functions g_ik have values that do not depend on the

> co-ordinates. There is no such thing as an empty space,

> i.e., a space without field. Space-time does not claim

> existence on its own, but only as a structural quality of the field"

The Usenet post by Paul Stewart is archived at

http://www.lns.cornell.edu/spr/2003-07/msg0052723.html

"Space-time does not claim existence on its own, but only as a structural quality of the field."

It is not especially easy to grasp the meaning, I suspect, but it might be worth thinking about. Eh quoted this in another PF thread and I was able to find an online reference in this Usenet post, which gives more context:

> However, I consider the ultimate words of Einstein on this matter

> to be the fifth appendix, added in 1952 (three years before his

> death), to the fifteenth edition of his book "Relativity: The

> Special and the General Theory." In that appendix, titled

> "Relativity and the Problem of Space," Einstein explicitly

> addresses the issue in question here. (Note that in the following

> "type (1)" space is Minkowski space.)>

> "If we imagine the gravitational field, i.e., the

> functions g_ik, to be removed, there does not remain a

> space of the type (I), but absolutely _nothing_, and

> also no 'topological space'. For the functions g_ik

> describe not only the field, but at the same time also

> the topological and and metrical structural properties

> of the manifold. A space of type (I), judged from the

> standpoint of the general theory of relativity, is not

> a space without field, but a special case of the g_ik

> field, for which -- for the coordinate system used,

> which in itself has no objective significance -- the

> functions g_ik have values that do not depend on the

> co-ordinates. There is no such thing as an empty space,

> i.e., a space without field. Space-time does not claim

> existence on its own, but only as a structural quality of the field"

The Usenet post by Paul Stewart is archived at

http://www.lns.cornell.edu/spr/2003-07/msg0052723.html

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