The uncertainty principle - A simplified review of the four versions

•First non-technical article to elucidate the four versions of quantum uncertainty.•It is shown that Ozawa׳s recent work upholds the intrinsic indeterminacy.•Ozawa׳s work shows that the statistical version of uncertainty is not self-sufficient.•Intrinsic indeterminacy is shown to be at the heart of all the other three versions.•The objective (ontic) side of Bohr׳s and Heisenberg׳s interpretations are highlighted.

The complexity of the historical confusions around different versions of the uncertainty principle, in addition to the increasing technicality of physics in general, has made its affairs predominantly accessible only to specialists. Consequently, the clarity that has dawned upon physicists over the decades regarding quantum uncertainty remains mostly imperceptible for general readers, students, philosophers and even non-expert scientists. In an attempt to weaken this barrier, the article presents a summary of this technical subject, focussing at the prime case of the position-momentum pair, as modestly and informatively as possible. This includes a crisp analysis of the historical as well as of the latest developments. In the process the article provides arguments to show that the usually sidelined version of uncertainty-the intrinsic ׳unsharpness׳ or ׳indeterminacy׳-forms the basis for all the other three versions, and subsequently presents its hard philosophical implications.