My understanding is that an observer can measure the precise location of a particle so long as the corresponding uncertainty in momentum measurement is not an issue and vice-versa.
Say there is such an observer, interested in the precise position of a particular particle. Now, consider a second, independent observer, unbeknownst to the first, who is trying to measure the exact momentum of the same particle without caring about the position. As a thought experiment, we assume that the two observers are somehow able to access the same particle at the same time in some way without being aware of each other.
Can both observers get their desired results?
Best Answer
They could not - don't think of the observers as people, think of them as experiments. If two individual experiments were taking place on the same particle simultaneously, there's no reason why they couldn't be combined into a singular experiment, and you'd then have an experiment that is able to determine both a precise position and momentum, which is impossible.