The HUP (Heisenberg Uncertainty Principle), which is what I assume you are asking about, has nothing to do with how things are measured, it is an expression of a fundamental limitation of nature.k9b4 said:Why does measuring the position of a particle change its momentum?
Is it because 'measuring' involves shooting EM waves or other particles at the particle, which changes its momentum?
It may, and it seems likely but I say again, this has NOTHING to do with the HUP. Did you bother to read the sentence directly after that one "Though widely repeated in textbooks, this physical argument is now known to be fundamentally misleading.[4][5]"k9b4 said:In this wikipedia article http://en.wikipedia.org/wiki/Uncertainty_principle, it states:
"This ascribes the uncertainty in the measurable quantities to the jolt-like disturbance triggered by the act of observation."
Does that mean that by measuring the particle (ie shooting EM waves at it) changes its momentum?
Why is it fundamentally misleading?phinds said:
k9b4 said:Why is it fundamentally misleading?
Nugatory said:It is misleading because it suggests that the particle has both a definite position and a definite momentum before we measure either, and it's just the unavoidable clumsiness of the measurement process that prevents us from discovering both.
In fact, the uncertainty principle is deeper than just unavoidable clumsiness of measurement. Any state in which the position is definite is necessarily a state in which the momentum is a superposition, and vice versa.
This phenomenon is known as the Heisenberg uncertainty principle, which states that it is impossible to know both the exact position and exact momentum of a particle at the same time. When a measurement is taken to determine the position of a particle, it inevitably affects the momentum of the particle, making it impossible to accurately measure both at once.
The uncertainty principle challenges the long-held belief that the physical world can be fully understood and predicted through precise measurements. It introduces an element of randomness and uncertainty into the behavior of particles, and shows that there are limitations to our ability to measure and predict their properties.
No, according to the uncertainty principle, it is impossible to accurately measure both the position and momentum of a particle at the same time. This is not due to limitations in our measuring techniques, but rather a fundamental property of particles in the quantum world.
The uncertainty principle is a fundamental principle of quantum mechanics and applies to all particles, regardless of size. However, its effects are only noticeable at the subatomic level and are negligible for macroscopic objects.
The uncertainty principle is related to the concept of wave-particle duality, which states that particles can exhibit both wave-like and particle-like behavior. It is also closely linked to the concept of quantum entanglement, where the properties of two or more particles become linked and cannot be described independently.