Tim88

Hi Madmac probably you arrived when I took an extended holiday. That issue was elaborated in the following threads: http://www.scienceforums.net/topic/97105-is-space-time-a-physical-entity-or-a-mathematical-model/page-11#entry943184 http://www.scienceforums.net/topic/98845-models-for-making-sense-of-relativity-physical-space-vs-physical-spacetime/ In a nutshell, the experimental support for theory (SR, GR, QM) apparently obliges us to accept that Space is not merely a mathematical concept that relates to nothingness. But what is it made of? I'm afraid that the definite answer to that question may always be beyond our reach. Currently, the only thing we can do is to invent models. A promising looking route was that of unifying field theories, but as far as I know, a well developed and satisfying theory is still wanting (although there are some around that seem to have potential).

That is better, however as I understand from Neumaier's book on QFT, it's inaccurate to put "the standard model particles and fields"; particles are assumed to be phenomena caused by fields. Maybe if you want to go beyond pure GR, you have to choose your favourite quantum theory! And if I'm not mistaken, even in absence of such particles or fields, the speed of light and the lengths of rulers are supposedly determined in GR. Further, "outdated" could merely refer to fashion; that does not suffice for making pertinent claims as if giving factual statements. So, now I am curious what of Einstein's paper has convincingly been disproved by later research. BTW, a similar paper stems from 1924 but it's not yet available on Wikisource, so for onlookers I chose the more accessible version. Similarly I often cite Einstein's 1905 paper for SR as it's in some points clearer and more precise than a number of later papers by other authors.

I have the same beef as some others here in the first posts. You may define space as volume only, but the claim that it is "not some kind of ether", is controversial at best. It directly contradicts Einstein's interpretation of GR. He argued that necessarily space is not physically empty. Of course, you could say that space is not some kind of ether, but instead contains some kind of ether; however most people would probably consider that a word game. Even more, "space" as a locally defined volume depends on the physical properties of that volume. In a nutshell: " "empty space" in its physical relation is neither homogeneous nor isotropic [..] The ether of the general theory of relativity is a medium which is itself devoid of all mechanical and kinematical qualities, but helps to determine mechanical (and electromagnetic) events. " - https://en.wikisource.org/wiki/Ether_and_the_Theory_of_Relativity Of course, it's easier to spot wrong or controversial formulations than it is to give right or uncontroversial ones. You could simply leave out the phrases "It is not something form of ether" and "not the volume of space", but that would be a little poor in view of the title. So, you could maybe state that space can be considered as a map (or part of a map, in view of space-time) that relates to a physical reality, some effects of which we describe with the map. Just my 2 cts. Another issue is with point 2: according to QFT, if I'm not mistaken, space is filled with fields. Probably it's better not to include "space time creation" in the topic "what is space made of". And please correct typo's: feilds ->fields Which is a topological space that is resembles Euclidean space at beach point. -> Which is a topological space that resembles Euclidean space at each point. (right?) [edit: a few additions]