akrain,
Yes, there finally are experiments to displace QM. To discuss these experiments, we need to discuss:
Magnetic Moments of Atoms
A magnetic moment μ in a magnetic field is known to precess. The torqe
is perpendicular to
L and makes it precess.
For a body that is rigid and has a magnetic moment, this precession can be smooth and uniform. However, electrons in orbit around an atom
cannot be modeled as rigid. Consider the hydrogen atom in a magnetic field
B, for example. The electron below is shown in five different places along its orbit:
The torque that causes the precession goes as:
)
It is amazing to see that the torque at positions 2 & 4 vanishes!
Also, the torque at positions 1 & 3 is at a maximum!
The torque at position 5 has a z component!
(Take note: This means that L
z is not constant for a non-rigid magnetic moment precessing in a magnetic field).
This means that the motion of electrons around an atom
in a B field is not a smooth and uniform precession as we have been lead to believe!
The magnetic torque changes from max to zero twice with every orbit, and has z-components.
This motion is actually a wild nutation/precession, with the z-component of the angular momentum changing periodically.
This scenario will radiate, there is no question about it. Radiation friction will be generated. Now it is well known that nutational precessions accompanied by friction tend to change rapidly. Spin a top. Watch it precess and wildly nutate at first. The friction immediately dampens the nutation so that it goes into a smooth, stable, precession. The friction dampens the wild nutations first.
The same thing will happen here. The radiation friction will dampen the nutations in such a way that the electron is forced into a stable orbit. Otherwise, the electron will either decay into the nucleus, or be cast away in ionization. These don't occur, so the electron must be forced into a smooth, stable orbit. And there are just two stable orbits, one with L UP and one with L DOWN.
We finally see that angular momentum and magnetic moments are not "quantized" by the strong magnetic fields of the Stern Gerlach experiment. They are induced.
For example, if silver atoms enter a strong magnetic field with continuous values of L
z, then they are immmediately induced into either the UP or DOWN states.
Remember: Induced, not quantized.
The New Stern Gerlach Experiments
The usual Stern Gerlach Experiment setup is like this:
A huge magnetic field with a large derivative in the z-direction is used to separate the UP and DOWN magnetic moments of silver atoms. We see that the output is induced into the "UP" or "DOWN" states as predicted.
But notice that it is the derivative of the B field
that does the separation, and not the B field itself. However, it is the B field itself that does the inducements. So what we need is:
We need a B field that has a strong z derivative,
but the B field itself is small.
This way, the small B field will not be able to induce the silver atoms to the UP and DOWN states, but the z-derivative will still deflect the atoms. Such a B field is possible. If one could superimpose magnetic fields (this is more difficult than it sounds), then:
one could end up with a field that had a large z-derivative, but a small value for the field itself. This would allow the silver atoms with their continuous values for L
z to be deflected without a huge B field inducing them all towards the totally UP or DOWN states. This would allow
the continuous Lz spectrum to be recovered, proving space quantization and quantized spin incorrect.
Andrew A. Gray