B Is quantum superposition involved in the Stern-Gerlach experiment?

[Curious Cat]

TL;DR Summary

I am trying to explain the SG experiment to children, in plain English,
in simple terms, they can actually understand.

This is how I explain it, away, now:

Upon entering the magnetic field the silver atom's valence electron's
electric field aligns itself at right angle/s to the magnetic field,
the quickest/shortest way it can, as they are wont, to do, somehow, and
the rest follows, naturally. And if U are thinking "Why not just say
that its magnetic field aligns itself anti/parallel, to it, as they are
wont, to do"!? Well, I can understand how it would align parallel but
how about antiparellel? Even though I think I can actually explain it,
in a nonhomogenous field, by ignoring the weak/er side.

But I am thinking ahead to an MRI machine, which I think uses a homogenous field,
even though I think I have an alternative explanation, for that too. But
the main reason, I prefer the electric field, explanation, is because
that leaves the option of it going into a quantum superposition, of
both, spin/s, up and down. Although I suppose the end result is the same,
so it makes no difference. Or is that the act of measurement?

 

[mfb]

The electric field of the valence electron doesn't do anything. It's spherical anyway.

the quickest/shortest way it can

Any sort of "goes to the nearest state" doesn't explain how you can get two results more than 90 degrees apart in subsequent measurements.

Your description has nothing to do with the physics, and it would lead to results inconsistent with observations.

As a classical analog, the measurement is a bit like a slit and you try to pass a transversal bar through the slit. There are just two orientations where the bar fits. If the bar has any other orientation it gets rotated. Smaller rotations are more likely.

 

[Curious Cat]

That electron has a magnetic moment, which is the result of its quantum spin, which tells me that it must be spinning, like crazy, and I can see its electric field lines getting dragged/swept backwards, by it, so that it does have a direction, in the direction of the spin.
. Yes I know, it's not supposed to actually/physically spin and if it did, it would have to be faster than c, but my little friends are happy, with my explanation. It's better than nothing.
. And why couldn't an electron spin faster than c, whatever that actually means?
It's a quantum particle and it's not like it's actually going anywhere.
Besides, we know that it does not radiate, away, in an orbit/al, so they don't exactly have to follow our macro laws. Oh, please don't tell me that they don't actually orbit, the nucleus. That's another story.

 

[PeroK]

Summary:: I am trying to explain the SG experiment to children, in plain English,
in simple terms, they can actually understand.

This is how I explain it, away, now:
Upon entering the magnetic field the silver atom's valence electron's
electric field aligns itself at right angle/s to the magnetic field,
the quickest/shortest way it can, as they are wont, to do, somehow, and
the rest follows, naturally. And if U are thinking "Why not just say
that its magnetic field aligns itself anti/parallel, to it, as they are
wont, to do"!? Well, I can understand how it would align parallel but
how about antiparellel? Even though I think I can actually explain it,
in a nonhomogenous field, by ignoring the weak/er side. But I am
thinking ahead to an MRI machine, which I think uses a homogenous field,
even though I think I have an alternative explanation, for that too. But
the main reason, I prefer the electric field, explanation, is because
that leaves the option of it going into a quantum superposition, of
both, spin/s, up and down. Although I suppose the end result is the same,
so it makes no difference. Or is that the act of measurement?

The electron’s spin state evolves during its time in the magnetic field, but it doesn't align itself with the magnetic field. No measurement of electron spin takes place.

Your explanation is not quantum mechanical.

The SG experiment, like most all QM phenomena, cannot be understood without quantum superposition.

The electron’s spin state is an unknown superposition of spin up and spin down relative to the magnetic field.

 

[mfb]

That electron has a magnetic moment, which is the result of its quantum spin, which tells me that it must be spinning, like crazy, and I can see its electric field lines getting dragged/swept backwards, by it

Spin is not a rotation of anything. There is no such process.

but my little friends are happy, with my explanation. It's better than nothing.

I disagree. I think blatantly wrong descriptions are worse than nothing. They only lead to misconceptions that are hard to get rid of later.

"U"/"Ur" are not words, by the way. This isn't twitter, we don't have character limits.

 

[Curious Cat]

The electron’s spin state evolves during its time in the magnetic field, but it doesn't align itself with the magnetic field. No measurement of electron spin takes place.

Your explanation is not quantum mechanical.

The SG experiment, like most all QM phenomena, cannot be understood without quantum superposition.

The electron’s spin state is an unknown superposition of spin up and spin down relative to the magnetic field.

Thank U, for Ur reply, but:
. Surely the electron's magnetic field gets aligned anti/parallel to the magnetic field, which means that its electric field's equator gets aligned at right angle to that, which means that it spins either left or right, relative to it.
. I agree. I am trying to explain this to children classically. They can understand CM, because of their LEGO and Meccano sets, but not QM.
. So are U saying that QSP is involved? And that SG doesn't actually measure the spin!?
But all the electrons in a spin-up beam stay spin-up, thru another magnet/s in the same plane.
I do remember the Encyclopedia Britannica, Philosophy of Physics, The Principle of Superposition, and I think some other site?s, saying that if U cascade these stages as HVH and U recombine the 2 beams coming out of V back together the end result will be like it wasn't even there!? And I do accept that. But EB was talking about just electrons, although I suppose that shouldn't make any difference.
. So when does measurement actually take place? When a beam is observed!? Or when we can even just tell which path an electron took!? Surely the SG magnet/s is not like a beam splitter.

 

[Curious Cat]

Spin is not a rotation of anything. There is no such process.I disagree. I think blatantly wrong descriptions are worse than nothing. They only lead to misconceptions that are hard to get rid of later.

"U"/"Ur" are not words, by the way. This isn't twitter, we don't have character limits.

. Seriously, now:
. Then what produces the magnetic field/moment?
It can only be the spinning/movement of the charge.
. Maybe, but, it's a start, and I will find the ultimate solution, if it's the last thing I do.
If you can give me a better explanation, I would welcome it.
So are you saying we should not teach the children the solar system model of the atom!?

 

[PeroK]

Thank U, for Ur reply, but:
. Surely the electron's magnetic field gets aligned anti/parallel to the magnetic field, which means that its electric field's equator gets aligned at right angle to that, which means that it spins either left or right, relative to it.
. I agree. I am trying to explain this to children classically. They can understand CM, because of their LEGO and Meccano sets, but not QM.
. So are U saying that QSP is involved? And that SG doesn't actually measure the spin!?
But all the electrons in a spin-up beam stay spin-up, thru another magnet/s in the same plane.
I do remember the Encyclopedia Britannica, Philosophy of Physics, The Principle of Superposition, and I think some other site?s, saying that if U cascade these stages as HVH and U recombine the 2 beams coming out of V back together the end result will be like it wasn't even there!? And I do accept that. But EB was talking about just electrons, although I suppose that shouldn't make any difference.
. So when does measurement actually take place? When a beam is observed!? Or when we can even just tell which path an electron took!? Surely the SG magnet/s is not like a beam splitter.

The measurement takes place when the silver atom collides with the screen. Electron spin is inferred from that.

If you look at the history of QM, all four quantum numbers for the hydrogen atom were inferred from its spectrum alone. There were no direct measurements of energy, angular momentum or spin. Only from measurements of the wavelengths of photons in the hydrogen spectrum.

This is a hallmark of QM.

SG provides evidence for electron spin, but it's not a direct measurement thereof.

This is why the most important thing about QM is learning to think differently and not trying to squeeze QM into classical pigeon-holes.

I think from this last post you are showing signs of starting to digest this!

 

[PeroK]

Looks like the not-so-curious cat has gone?

 

[berkeman]

10-day vacation...

 

[PeroK]

Not just a cat nap then!