the.com/uncertainty principle

means A rule from quantum physics stating that certain pairs of properties—like a particle's position and momentum—cannot both be measured with perfect precision at the same time; the more exactly you pin down one, the blurrier the other gets, and this isn't a flaw in our instruments but a basic feature of reality itself.

from Coined in German as 'Unschärferelation' (literally 'unsharpness relation') in 1927 by physicist Werner Heisenberg, who showed mathematically that measuring a particle's position disturbs its momentum, and vice versa—not because our tools are clumsy, but because at quantum scales a particle simply doesn't possess both values with infinite precision simultaneously. The English term 'uncertainty principle' became the standard translation, though some physicists have argued 'indeterminacy' better captures Heisenberg's original point: this is about what nature allows to exist, not merely what we're able to know.