Re: special relativity: accelerated frames

["RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>]

Denker posted in part:
> > I notice that the stuff piled on the back seat of my car 'rushes
> > forward' onto the floor,
>
> OK.
>
> > (presumably, somehow pulled forward by the outside world)
>
> It is fashionable to presume that.  That's Mach's principle.
>
> However... AFAICT Mach's principle makes no useful
> predictions.

No quibbles to the above.  However to the below . . .



> Indeed, if
> it makes any predictions at all, it predicts that if you removed the
> "outside world" the stuff in the car would behave differently
> -- which is
> not true.

I can only ask how do you know?  How do you know that it isn't true  that if
we "removed the outside world" , the stuff in the car would behave
differently.

It is precisely because we can't really know, because we can't do the
experiment that the statement about Mach's principle and useful predictions
has weight.