Interesting quote from a book by Einstein

[marcus]

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

 

[Turtle]

Space-time has its existence on g_ik, your right something worth thinking about, why is this?

 

[marcus]

Originally posted by Turtle
Space-time has its existence on g_ik, your right something worth thinking about, why is this?

I have to go, before parking downtown gets too bad, but will be back.

I won't be able to answer your question anyway

I have found Rovelli's book (the philosophical parts) helpful

http://www.cpt.univ-mrs.fr/~rovelli

the link to the book "Quantum Gravity" he is writing is
down at the bottom of the page

I'm thinking of the example on page 40,41 of the two stars
one is rotating and one is not
with respect to what? are they rotating and not rotating.

and his example of the expanding cloud of galaxies

the bewilderment about space and time goes way back and
he is both a physicist and a science-historian
so he brings a certain amount of perspective to it

but other people may have found other discussions of the same problems that they prefer

i will get back to this later today

 

[jeff]

Originally posted by marcus
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."

This final development in einstein's view of the ontological status of spacetime was a direct result of his research on the "unified field theory": If the metric component fields g_μν transform into and out of other substantial physical fields, as claimed by UFT, than a dualist view of physical reality in terms of an autonomous spacetime must give way to a purely relationalist view, even though absolute motions may still be defined which are not relative to absolute spacetime, but to the spacetime constituted by the totality of physical fields (rather than by some of them).

 

[Sariaht]

The original book was written in a german language. Space-time is in my language "rymdtid". He want's to say:
Time in space does not claim existence on its own,
but only as a structural quality of the field or the net.