Depends on the knowledge and understanding of the practiitoner.
"Just like economics.
It all depends on the skill of the folks involved. Hence, "...a little uncertainty never stopped anyone from either looking hard at reality and creating wealth." They can also use it productively to gauge the effects of various variables for the purposes of protecting rights, or for providing monetary input, as the Fed does.
with different distances
and then start talking relativity not to mention tidal effects, but this is really what life's all about. There's always a lot to it and at some point that we've got to stop measuring/calculating and go with what we got.
We all have to pick the point that suits our own needs, and when it comes to econ my needs mean I've got to know what's going on well enough to make a profit; which is why for me the urban legends I tried listing in post 72 just don't cut it.