Electron spin

@humy said
Just look it up in wiki and you see how I define it.
I define it whichever way science does, just like I should.
Unlike you, I don't make crap up.

Go ahead and copy and paste it from wikipedia since you do that best. Prove that it meets the definition of "spin".

@metal-brain said
Go ahead and copy and paste it from wikipedia since you do that best. Prove that it meets the definition of "spin".

"Prove that it meets the definition of "spin"" according to who or what? You or science?
And which definition of 'spin'? The 'spin' defined by science or your personal definition of the word 'spin'?
If the former, prove that the said spin by wiki is not that defined by science.
If the latter, why should we care if it doesn't conform to your personal definition of 'spin'? I don't.

@metal-brain said
I'm just going by the wikipedia links you keep referring me to. It isn't really "spin".

"Because of this, it turns out that the notion of a quantum particle literally "spinning" about an axis does not exist."

https://en.wikipedia.org/wiki/Angular_momentum

"In quantum mechanics, angular momentum (like other quantities) is expressed as an operator, and its one-dim ...[text shortened]... ar momentum, but this angular momentum does not correspond to spinning motion in the ordinary sense"

Yeah, it is really "spin." That's the name we've given it. A charm quark is a charm quark regardless of how charming it is.

@kazetnagorra said
A charm quark is a charm quark regardless of how charming it is

, or, for that matter, regardless of how repulsive or ugly it is.

@metal-brain said
I'm just going by the wikipedia links you keep referring me to. It isn't really "spin".

"Because of this, it turns out that the notion of a quantum particle literally "spinning" about an axis does not exist."

https://en.wikipedia.org/wiki/Angular_momentum

"In quantum mechanics, angular momentum (like other quantities) is expressed as an operator, and its one-dim ...[text shortened]... ar momentum, but this angular momentum does not correspond to spinning motion in the ordinary sense"

The laws of physics are invariant under rotations. Someone called Emmy Noether proved that a symmetry implies the existence of a conserved quantity. The conserved quantity in the case of invariance under rotations is angular momentum. Orbital angular momentum and spin are jointly conserved, it is their sum that is conserved. This means that spin is a form of angular momentum.

In Quantum Field Theories the elementary particles are assumed to be point-like. However, in String Theories they are assumed to be small loops. We have theories of these things and can make statements about the objects in the theories, but that is different from making statements about the things in themselves. So, yes, intrinsic spin is not the same as macroscopic rotation.

@deepthought said
The laws of physics are invariant under rotations. Someone called Emmy Noether proved that a symmetry implies the existence of a conserved quantity. The conserved quantity in the case of invariance under rotations is angular momentum. Orbital angular momentum and spin are jointly conserved, it is their sum that is conserved. This means that spin is a form of angular m ...[text shortened]... ts about the things in themselves. So, yes, intrinsic spin is not the same as macroscopic rotation.

"So, yes, intrinsic spin is not the same as macroscopic rotation."

What is the difference?

@kazetnagorra said
Yeah, it is really "spin." That's the name we've given it. A charm quark is a charm quark regardless of how charming it is.

Define spin.

@metal-brain said
Define spin.

Look it up at wiki to see how science defines it because THAT is how we define spin.

@metal-brain said
"So, yes, intrinsic spin is not the same as macroscopic rotation."

What is the difference?

For starters, one has speed of rotation and the other doesn't.

@metal-brain said
Define spin.

https://en.wikipedia.org/wiki/Spin_(physics)

@kazetnagorra said
https://en.wikipedia.org/wiki/Spin_(physics)

Define intrinsic.

@humy said
For starters, one has speed of rotation and the other doesn't.

Then one is spin and the other is not.

@metal-brain said
Define intrinsic.

intrinsic[ in-trin-sik, -zik ]

adjective
belonging to a thing by its very nature:
the intrinsic value of a gold ring.
Anatomy. (of certain muscles, nerves, etc.) belonging to or lying within a given part.

@metal-brain said
"So, yes, intrinsic spin is not the same as macroscopic rotation."

What is the difference?

I discussed that in the second post on the first page of this thread.

@kazetnagorra said
intrinsic[ in-trin-sik, -zik ]

adjective
belonging to a thing by its very nature:
the intrinsic value of a gold ring.
Anatomy. (of certain muscles, nerves, etc.) belonging to or lying within a given part.

So it's spin is intrinsic? Does that mean it cannot help but spin? Is spinning the nature of an electron? What does that mean?