@Mithrandir24601 So this is where I'm at. I'm understand when glS says "don't really understand the need of a "way out". The scope of the result is as general as it gets. It holds at any point in time. You can apply it immediately after a measurement, the only caveat is that the post-measurement result will be different then the state before measurement, and therefore the quantities (averages and variances) will be different ..."

Taken from the original joshphysics derivation's comment section:

joshphysics any idea what the error term involved in the approximation might be?

MoreAnonymous That's a great question that I've never considered oddly enough (probably because I've never really used this in practice, but only as a conceptual tool for understanding the implications of quantum mechanics). I'm curious though now, and if I find something, I'll let you know.

There is a paper that might discuss this called "Mathematical analysis of the Mandelstam–Tamm time-energy uncertainty principle" by Gray and Vogt, but I haven't read it in detail, so I'm not sure at the moment.

Oh

MY

twitter.com/Ion_busters/status/1174660771256721409?s=08

This is very suspicious

@Mithrandir24601 :O