crastinus said:
Is that the question you guys are discussing? Or something else?
It's basically that, but the caveat is that they'd rather blast you with math which isn't physical. Coordinate charts aren't physical. Your question was a physical one in nature, and I took issue to how it was being approached. I, also, philosophically differ with them. This has been my stance since my first GR course, and it's a hill I die on, but that's for another thread.
Now, I realize it wasn't the time nor place for it, so in the spirt of PF I will answer your OP question to the best of my ability, and if you're more into the math-y answers than by all means tell me that, and I'll move on.
crastinus said:
What is the relationship between the electromagnetic field and space-time?
If you view this from the lens of general relativity, and I'm assuming you are since this is the relativity forum, the relationship between the E+M field and space-time can be described in the concept known as "minimal coupling". It's *mainly* a math procedure, but the result of it is physical (if you go through the procedure for the given field, this will always satisfy the equivalence principle, and general covariance). If you take your well known E+M relationships (those on a minkowski (flat) space time), and try to generalize them (riemannian (potentially curved) spacetime), what you'll see is that the relationships between your electromagnetic fields and potential don't change, and neither do your conservation laws.
But what DOES change? The dynamics of your electromagnetic fields. In other words, your Maxwell Equations become dependent on the geometry of your spacetime (seems kind of obvious, eh?).
crastinus said:
Is there a relationship between space-time and the field (I presume) created by the strong force (however negligible it may be at any significant distance)?
No, the relationship is simply that you take spacetime to be fundamental in general relativity. Spacetime exists, and things get coupled to the geometry. You can then talk about those relationships, but first you must ask "how does the (potential) geometry effect my dynamical equations?". As far as I'm aware, there is no physical system that doesn't care about the curvature/geometry of spacetime.
crastinus said:
I am in particular wondering whether there is one big EM field that is everywhere in space or something else. I googled around and got only some papers that were way beyond me.
Yes Sir! That's how you should think about it. However, if you want to be a relativist, you first have to think of your spacetime, then your E+M field comes next.
I do apologize for the inconvenience I have caused by having your thread shut down for a few days, as your question is a fun one to ponder when starting out in GR!