Originally posted by KazetNagorraThe nature of measurement of position is what I was referring to. Using photons to measure position may affect the accuracy of the experiment because of the collision.
An "observer" in quantum mechanics does not require a person, nor an experiment. In any case, check out Bell's inequality.
I guess the main reason physicists tend to accept quantum mechanics is that it is very accurate.
All particles, regardless of the speed at which they travel, exhibit both wave-like and particle-like properties. The "wave" and ...[text shortened]... articles; particles are never a "pure" wave (sine) or a "pure" particle (delta peak).
http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics/Atomic_Theory/Electrons_in_Atoms/Uncertainty_Principle
Originally posted by Metal BrainWhat are you implying?
The nature of measurement of position is what I was referring to. Using photons to measure position may affect the accuracy of the experiment because of the collision.
http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics/Atomic_Theory/Electrons_in_Atoms/Uncertainty_Principle
Originally posted by Metal BrainThat surely depends on the experiment. I am fairly sure however that I have never heard of an experiment in which electrons were observed via photons.
That you can't measure the position of the electron without hitting it with a photon. This could ruin the experiment.
I believe the most popular method for particle physics is the use of bubble chambers or equivalents.
Originally posted by twhiteheadAccording to wikipedia bubble chambers are largely a thing of the past. They are also described as being filled with liquid or gas.
That surely depends on the experiment. I am fairly sure however that I have never heard of an experiment in which electrons were observed via photons.
I believe the most popular method for particle physics is the use of bubble chambers or equivalents.
http://en.wikipedia.org/wiki/Bubble_chamber
Lets eliminate the simple things first. Are these experiments done in a vacuum?
Originally posted by Metal BrainThere are several ways to measure the position of an electron, but the important point to realize is that an electron never has a definite position. It is spread out over space.
That you can't measure the position of the electron without hitting it with a photon. This could ruin the experiment.
Originally posted by KazetNagorraThat is very interesting. Could you provide me with a good link so I could learn more about that?
There are several ways to measure the position of an electron, but the important point to realize is that an electron never has a definite position. It is spread out over space.
Originally posted by KazetNagorraMore accurately, it is spread out over space-time. Its position in space can be very definite at the expense of uncertainty in time.
There are several ways to measure the position of an electron, but the important point to realize is that an electron never has a definite position. It is spread out over space.
Originally posted by Metal BrainYes, I noticed that, which is why I added - or equivalents. My point is that we do not bounce photons off particles in order to 'see' them. Instead the particles interact with other particles.
According to wikipedia bubble chambers are largely a thing of the past.
Lets eliminate the simple things first. Are these experiments done in a vacuum?
No.
Originally posted by twhiteheadWhy not?
Yes, I noticed that, which is why I added - or equivalents. My point is that we do not bounce photons off particles in order to 'see' them. Instead the particles interact with other particles.
[b]Lets eliminate the simple things first. Are these experiments done in a vacuum?
No.[/b]
Originally posted by Metal BrainThe wavefunction, which in quantum mechanics has all the information about a particle (or collection of particles), is spread out over space about some expectation value <x>. The standard deviation of the position operator, Delta_x, is related to the equivalently defined standard deviation of the momentum operator, Delta_p, through Heisenberg's uncertainty relation. The Heisenberg uncertainty relation has nothing to do with measurement (at least directly) but is a consequence of describing particles in terms of wavefunctions. The Schrödinger equation will tell you how the wavefunction evolves in time.
I couldn't find anything to confirm your statement in that link. Are you sure you posted the right link?