# Thread: Simple solution to the QM question

1. Thinking about the initial premise and foundation of QM. It actually seems rather silly

Consider Bell's theorem, it is a bold claim towards something that no one has ever been able to do (and never will, proving a negative). This so called "spooky action at a distance" which is commonly known also as "quantum entanglement" could use some attention and lovin'

Say a counter argument was proposed to mr. Bell:
There is no quantum entanglement, but only conservation of angular momentum. If you split a moving and fast spinning piece of physical matter into two separate pieces and at the same time separate the courses of these two pieces -> these pieces will by definition (in terms of classical mechanics) have opposite spin states relative to their velocity vectors.

I wonder how mr. Bell would have responded to this counter argument.. Any thoughts?

2.

3. First, I'm no expert, I just read about this stuff. But my take is that QM requires that observation effects the state of the thing observed. So a set of particles could all have the state pi/4, until observed. When observed, they all collapse randomly, with say a 50% chance of spin up, and 50% chance of spin down. No two are correlated, if not entangled. If a particle is entangled with another particle, when you observed one there is a 100% chance the other will be the opposite, so they are correlated. So the problem with looking at it in terms of classical physics is that we can't say that one of them was spin up or spin down to start out with, we have to observe it for that to happen. They are just probability clouds.

The simplest experiment that shows this probability cloud nature is the Triple Phasor Paradox:
You take two polarizing filters, and you have one at theta = 0 that blocks all light polarized right/left, and one at theta = pi/2 that blocks all light polarized up/down, and put together they block out all light. But if you put a filter in between them turned to pi/4, light can get through. But if the light photons HAD a state before this happens, there is not way adding a third filter to filters they can't move through would let light through, because the first two filters already blocked out 100% of the possible states. But since they are probability clouds, the first filter blocks out 50%, the second filter blocks out 50%, and the third filter blocks out 50%, leaving 1/8th to get through. So they have no up/down state until its precisely observed.

edit: so to your point: Once we admit that observing one of these probability clouds changes it, than the model has to include spooky action at a distance, because if we know two of them are entangled, and we've observed one, than our information about the other entangled one increases...It goes from having a 50/50 probability to have a 100% probability of being correlated with the one we observed.

4. The polarization puzzle can be solved via classical mechanics collisions of oscillating particles. The 90 degree orientation between two lenses causes some part of the photons to reflect back on the first lens, and then most that are left after that are reflected back by the second one due to their perpendicular polarization (plane of oscillation). Even in this case there is actually leakage and some photons get through.

Notice that the third lens has to be inserted between the two that are oriented by 90 degree difference. Now you insert a 45 degree oriented lens after the first one and classical mechanics collisions within the lens cause change in the polarization. It is a well known fact that polarization no longer remains after reflection. So by definition the inserted 45 degree oriented filter will destroy the filtering effect of the first lens (for the photons that do get through) due to reflections within the medium.

It is quite possible that quantum entanglement is nothing more than conservation of angular momentum of elementary particles. Classical mechanics can indeed provide a possible explanation.

5. Originally Posted by van erst
It is quite possible that quantum entanglement is nothing more than conservation of angular momentum of elementary particles. Classical mechanics can indeed provide a possible explanation.
No it can't. The other aspect of quantum entanglement that the conservation laws do not account for is the effect of the superposition of the multi-particle quantum state. Even though the conservation laws provide the correlation between the two particles, the actual values of each particle are a superposition of possible values. Bell's theorem is about demonstrating that the particles do not have definite values unless they are measured. It rules out the idea of a pair of particles being created with random but correlated definite values.