Originally Posted By: redewenur
Uninteresting? - sure, whatever lights your fire; but [frame dragging] 'not relevant'? - any distortion of spacetime is relevant to frames of reference.


It sounded like the article used that frame dragging to show that rotation is relative to the massive things around it. But surely it isn't?

Or is it really? Do we feel centrifugal force on a roundabout because it's spinning relative to loads of massive material in the universe? And it would be equally valid to say that other stuff is spinning while we're standing still? That's amazing. But if it's not that then the whole frame dragging thing is going off on a tangent for the article, which is what I found a bit frustrating.

Originally Posted By: redewenur

azard a guess that Bill's intention is to try to gain insight into what happens specifically in terms of frames of reference.


Yea and I think that's what he's done, reminded us that pretty much everything is accelerating pretty much all the time, at least its constituent parts are.