[yor_on]

Although, your universe is what you see, do you see what I say John?

[acsinuk]

The existing time/space frames of reference in my view are secondary and do not consider what the universe is made of?  We know that matter is made of molecules of atoms and that inside the molecule is electromagnetic and electrostatic stuff.   Now that stuff is fundamental to the whole universe,   So the most important frame of reference is electromagnetic and we must at all times conserve the positive and negative charge balance inside a magnetic enclosure.   The MKS system needs expanding to include electrical units V*I*Cos$ which will define where the charges are electromagnetically as well as physically. CliveS

[JohnDuffield]

you're correct, I don't know either what I mean, I have a feeling for what I want to get to, and it has taken me years to recognize the importance of it. I started with wondering what 'frames of reference'  meant, and I'm still stuck on this one. But I have a hope that you guys will help me there, if you start to wonder about it.

When it comes to special relativity, a frame of reference is little more than a state of motion. When you add general relativity into the mix, it's also a depth of potential thing. IMHO the important thing to appreciate is that it's an abstract thing. You cannot point up to the clear night sky and say "hey look, there's a reference frame".   

Although, your universe is what you see, do you see what I say John?

Yes. But when you see something different to me, we're smart enough to get our heads together and compare notes, then work out that universe is really like.

Spelling sux. the worst of it is that writing too much English, I've found myself just as bad in Swedish

Hurdy gurdy hurdy!

[acsinuk]

The reference frame at present is space/motion related and that is part of the problem. The centre of the system used to be earth, then the sun and now it is the black hole at the centre of our galaxy Sag A* which is the magnetic hub.
So we must measure everything using our dimension system from that hub including the electric and magnetic orientation.
MKS + V*flux.   Where flux is area of I*Cos$
The x=0, y=0 and z=0 is okay [and our sun is x=27000 Ly ] but flux at galactic hub is induced -180deg as stars will then be 0deg orientation and all spin with north poles downwards thus repelling each other.       It complicates the physics I know but is necessary

[yor_on]

That doesn't matter for defining a experiment John. It do matter for making them into a conceptual reality describing a 'common universe', but there is a difference between that universe and what you measure. one is a abstraction, the other is your reality.