If a particle gives off its own light, how can we never know its position as well as its momentum, as we can see it and thus measure its speed, and know its velocity? How does the Uncertainty Principle treat this circumstance?
It thought that's how it was? How do quantum particles have inherent uncertainty?'photons measuring the position and therefore affecting the momentum' etc., but that's missleading.
That's the point of the Heisenberg Uncertainty Principle. It specifies this as being a fundamental element of the quantum world. This has nothing to do with measurement accuracy, which is not limited in any way. You can measure any single property to any degree of experimental accuracy. It is only certain *pairs* of attributes, called non-commuting or complementary, which are affected.It thought that's how it was? How do quantum particles have inherent uncertainty?
Yes, this is what I thought HUP meant. We have to shine a wave onto a particle to measure it. The weaker that wave is, the less it affects the momentum of the particle but the less precise the position can be known. (Since the particle could be any where between two wave crests.) Of course, if you used a higher frequency wave, with less area between the crests, you would know the position better but the momentum would be affected as you would be hitting it with more energy.When you measure a particle's position, you squeeze the wavefunction into a small range of positions, but extend it out in momentum space.
The particle DOES have a theoretical average position and average momentum based on the state wavefunction. We just can't measure it.
I completely agree with this view.It's my personal belief that we should throw away the word 'particle' to describe such structures, or at least be much more careful when using it and explaining it to newcomers to subatomic theories.
I can only repeat what I wrote in post #3... this is what I thought HUP meant. We have to shine a wave onto a particle to measure it. The weaker that wave is, the less it affects the momentum of the particle but the less precise the position can be known.
... do not confuse uncertainty due to the HUP with uncertainty due to inaccuracy of measurement. The HUP says that a quantum state has an intrinsic uncertainty regarding position and momentum w/o the need to refer to any experiment, measurement, ...