What is "the fabric" of space-time?

I think what is causing the problem is the word 'physical'. Why is it that you think the field is not physical? Are you considering the properties of mass/energy to be what defines something as physical?From my (admittedly very limited) understanding of what cavediver said, there isn't really any such thing as mass/energy, but rather the nature of the field when viewed in a certain way appears to be mass/energy. This means that everything is the field, and the field is all there is.Now I would consider 'physical' (in the context of physics) to mean something which contributes to the nature of 'existence' (whatever that may be). If the field is the only thing that actually exists, and the field is reality as cavediver suggested, then I don't think there could be anything more physical than that.I also didn't get the impression that the field is 'nothing', but rather than the field is 'fundamental'. When people have responded to the question 'What is the field?' with the answer 'The field isn't anything' I don't think that meant that the field is 'nothing'. I think that meant that there isn't anything more fundamental than the field, its just the field. There are no building blocks in the way you can say that a nucleus is protons and neutrons, or a proton is different quarks etc.To the people who actually know what they're talking about here, is any of what I said accurate or is it all way off the mark?

Well we agree on that then. No, what was said is that the field is the only thing that exists. There is nothing but the field. Anything else that appears to exist is really just the field. There isn't anything more physical than the field, because the field is the universe.Again, when cavediver or anyone else said the field is 'nothing' (if indeed he did say that, I haven't checked), I think this is referring to the fact that the field is fundamental. It has no constituent parts, it's just the field.