Thread 16825554

Without bullshit analogies or schizobabble about symmetries

>>16825554 (OP)
Explain what? You already found the wikipedia page which is a good place to start.

>>16825555
tf is intrinsic angular momentum of a point particle/field

>>16825556
It is what it is.

>>16825557
Yeah I don't know either

>>16825554 (OP)
Certain particles have something that *behaves like* a quantized version of spin angular momentum, but which is a purely quantum mechanical effect.

That's the extent to which the concept is understood.

>>16825557
this is what I'm talking about

>>16825556
So like you have a ball. Make it spin. It has some angular momentum. Imagine if that ball were infinitesimally small. It still has that angular momentum despite having a zero radius. That's spin.

>>16825564
>>16825568
>>16825557
>>16825554 (OP)
it doth be that which doths'd it to be, perforce

this thread

Magnets, that's the best analogy.

>>16825580
that's part of what I'm trying to understand. Everywhere else magnetic fields are caused by current/changing E field, but then particles can just pull "intrinsic" angular momentum out of their ass

>>16825578
made me lol, thanks anon

>>16825582
Well, spin of a photon is related to the phases of the electric and magnetic relative to the each other.

>>16825588
I know. But the more I learn about photons the more they piss me off. I don't get how a wave in a vector field can become a photon of you go small enough

As with all things in science, "what it is" is less important than "how you measure it."
Introducing: The Stern–Gerlach experiment.
Silver atoms were shot through a polarized magnetic field. Some atoms shoot up. Others shoot down. "Spin" is a measure of the feature which determines the direction and magnitude of this shift in direction.
This was how it was discovered and is basically how it is measured in fundamental particles today.

>>16825618
that's a bitchmade view of science

>>16825621
Nah. You're just gay.

>>16825554 (OP)
You can't spin?
Do you have Trump cankles or something?

Spin is a social construct fitted to a unknown parameter.

There is no accepted view of what spin is in quantum mechanics; but interestingly, because spin is a generic property of conservative fields, it can be formulated and experimentally created in other media like water and acoustic sound waves.

In all other media apart from quantum mechanics and electromagnetism, spin is always an angular momentum point particles have at every point in space which causes them basically to perform tiny little elliptical orbits in space. That is what spin is. You can manipulate these orbits so on one end you have perfectly circular "polarization" of water particles and on the other perfectly linear "polarization" which is just a particle oscillating back and forth in a line.

spin--a not so subtle anagram for nips--is an archaic word invented by rich, sexist white men to devalue the contributions women made to particle physics.

>>16825618
So the atoms act like monopoles with random polarity? How is it not just magnetism?
I only know of polarized electromagnetic fields, or is it "polarized" as in "it's a dipole", are they doing some weird woo fuckery?

>>16825554 (OP)
>schizobabble about symmetries
nobody can help you if you insist on being retarded

>>16825554 (OP)
>schizobabble about symmetries
I guess conservation of energy, momentum, and angular momentum is too schizo for you too huh? Just say God did it and leave real knowledge to the big boys

>>16825554 (OP)
>Explain spin
>Without bullshit analogies or schizobabble about symmetries
So, don't dumb it down, but dumb it way, way down. Got it.

>>16825554 (OP)
Actually spinning objects in magnetic fields have certain properties like resisting outside effects of other magnetix fields. 'Spin' for particles have similar properties.

1/2 vs 1 spin is much more annoying to explain

>>16825556
QM fields bubble so hard that points waviate in the ripples when you look for them.
And you are quite dizzy so that the reference frame seems to be rotating. That's the alcohol talking.

>>16826156
How many spin fractions exist?

>>16826156
>1/2 vs 1 spin is much more annoying to explain
no way one could explain that without using the concept of rotational symmetries of wave functions

>>16826156
>1/2 vs 1 spin is much more annoying to explain
Dirac belt trick bro

>>16826132
It's a dipole.
Spin is the "why" for magnets.

>>16826161
0, 1/2, and 1

>>16825556
https://youtu.be/6UyJqDzaQUs?si=XnM59Ed_vVYYSMCY

>>16826177
Then why one bonked up and other bonked down by rocknetic field, is because pico rock align with field? Is spin 1/2 trajectory not bonked by rocknetic field? Grug confused.

>>16826182
explains nothing. macroscopic rotation is just particles in orbital rotation. Spin is fundamentally different.

>>16826190
Smaller thing spin more

>>16826195
I understand conservation of angular momentum in the macro case. this is all classical. Spin is fundamentally different, you can't explain it with classical physics.

>>16826199
we know, that's why we're trying to find a theory of everything you sperg.

>>16826203
so your answer for what is spin is "we don't know"? seems to me like physicists have a pretty good grasp on what spin is, I just find the explanations vague

>>16826205
smaller thing spin more

>>16826187
bonk

Everytime someone references "particles" i drown a kitten.

>>16826187
Up side of rock bonk up side of other rock.
Down side of rock bonk other down side rock.
Up side rock stick to down side rock.

How fast does It spin?

>>16826215
Sound like normal sticky iron rock? Won't pico pebble turn around so up side point to down side very fast, and go in direction closest to sticky cobber? That's what sticky iron rock would do.

>>16826218
they aren't actually spinning, spin is more of an abstract value

>>16826214
It's that sort of behavior that made me lose faith in you, Lord.

>>16826226
Abstract particle,
Abstract spin.
Abstract viewer?

Is this a Jojo reference

>>16826226
youre so full of shit, please dont open your mouth

>>16826225
Yeah. It's kinda like that.
If you leave an iron bar in a strong enough magnetic field for long enough, the iron bar will become a "permanent" magnet because the spins align.

>>16826316
explain what is spinning

It is a portion of the dynamics of an electron which can only be described by quantum mechanics.

Now, the thing with quantum mechanics is that you cannot describe the dynamics of a particle as you would do with the flight of a butterfly. You can see what the butterfly just did and say whatever about it, but you can never really see what the electron does. Instead, you merely interact with it.

There are deep consequences about this fact into which I will not get. For our purposes, it is sufficient to say that our language struggles greatly to describe that which we do not see. The best we can do is to accept uncertainty.

Read the wikipedia article about the discovery of spin, and you will get a taste of how people use ordinary language to describe it. To me, the first thing to notice about spin is that, I repeat, it is an important part of the dynamical description of an electron which cannot be provided in any way by classical mechanics.

Sure, there is photonic spin, which sorta manifests classically as the vectorial character of the electromagnetic field. But that description fails to apply to electronic spin, since the electronic field (whatever that may be) is not observable.

You might be tempted to start away working on a better explanation of spin. You would fail, much like I did when I tried to do the same thing while ignoring the previous facts I stated earlier.

I took me a long time to see it as I do know, so don't feel bad if you struggle with understanding.

>>16825554 (OP)
it says it right there in your pic
momentum

I think, that spin has something to do with magnetism.

>>16825570
>zero radius but also has momentum
this shit sounds like schizobabble but infinitely smarter people than me insist it makes sense so I guess im just fucking retarded idk

>>16826392
classical angular momentum is defined from mass rotation around a point. Spin isn't like this at all, just saying it's momentum says next to nothing.

The big bang happens so often that it obligates inertial coalescence of the energy it spews

The tidal waves of energy churned outwards at 360 degrees in all directions, until all that remained was that which did not

The only shape in which that spewed energy may coalesce is a spinning sphere

To be any less geometry would contain insufficient energy to be a meaningful unitization of existence for that speck to be worthy of recognition as an individual, a piece separated from that initial burst of energy, designating it as matter, here on earth known as hydrogen

>>16826417
>So like you have a ball. It has some mass. Imagine if that ball were infinitesimally small. It still has mass despite having a zero radius. That's particle mass.
Nta, but the same deal. But that's under the assumption that all particles are infinitely small. What if they're actually strings? Who knows. Mass and momentum and ang momentum and energy are just properties of stuff that make up the universe. Is what it is, they exist without us here. It's up to us to describe them, they don't have to conform to our own experiences and prior definitions.

bump. none of you faggots gave a good answer

>>16825556
>intrinsic
Explain. What is the origin of spin.

>>16825554 (OP)
Good question. Follow up question, WTF is "color" when it comes to particles when it's impossible to see any colors at that miniscule scale? Why do they call it quantum chromodynamics when it has nothing to do with chromodynamics?

>>16827273
It's just a word physicists co-opted because they vaguely resemble RGB color math. QCT has nothing to do with actual color though, it's about the strong force which is between quarks and gluons

>>16827199
It's basically dark matter of particle physics. Nobody has seen it, nobody knows what that is or where does it come from and in general it makes no fucking sense at all, but it gives you physically correct results if you use it so everyone just make an important face and go along with it.

>>16827376
QCD* typo

>>16827383
That’s dumb, you could say the same thing about any inherent property of a particle.

>>16827389
And I do

Stern gerlach. Electrons in magnetic field get sent either up or down. No physical property explains this. Call it spin.
Einstein de haas effect + Barnett effect in tandem show a changing spin induces a changing rotation and vice versa, confirming this spin is a component of angular momentum.

>>16827376
How else would you describe an SU(3) symmetry where (+,+,+) = 0?

>>16825618
This

>>16825554 (OP)
it's literally just rotation
(and yes, it's superluminal)

>>16827404
>Electrons in magnetic field get sent either up or down.
Okay, so they're inherently magnetic
>Call it spin.
But why?? Explain.

>>16828428
Spin is a measure of the orientation of the magnetic moment.

How can something have a magnetic field without moving charge or changing E? Does spin actually mean the particle (or particle field) is moving in some way?

>>16828448
>How can something have a magnetic field without moving charge or changing E?
Ask your refrigerator magnet.

>>16828455
dummy that literally is caused by spin, which is what I'm asking about.

Spin is potential angular momentum. That's it. The more spin something has, the more angular momentum it can get from rotation.

>>16829966
3.999...

>>16829966
What is intrinsic angular momentum

>>16828428
>But why?? Explain.
Historical reasons - when physicists were starting to work out a more complete model of atomic physics they found that electrons had a property that behaved similarly to an orbital angular momentum, but quantized and indeterminant as a full vector quantity, and that this property resulted in a magnetic moment-like effect. Further experimentation revealed some behavior that couldn't be explained by this purely orbital angular momentum, so the first assumption was that there might be some quantum equivalent of spin angular momentum.

The name stuck, that's literally the only reason it's called spin instead of intrinsic angular momentum.

>>16827404
Not electrons in magnetic field. That would be just Lorentz force. It's neutral atoms in a non-uniform magnetic field.
It's called spin because its behavior resembles angular momentum.

>>16825554 (OP)
I'm not an expert, but afaiu, we don't actually know what spin is. it's like saying 0 or 1, just a state, but we have no clue about the fundamental answers to "what" or "why"
which is what I think people have been trying to tell you ITT

>>16825554 (OP)
Spin is intrinsic angular momentum; you can talk about classically without any quantum mechanics concepts. Angular momentum is a conserved quantity of the dynamics and you simply have to keep track of this additional intrinsic angular momentum along with the orbital kind. If you know what angular momentum is from mechanics, that’s all there is to it. It acts like a little magnetic moment and couples to magnetic fields the way you’d expect any “spinning” charge to.

What makes spin weird and frustrating is how it behaves under a change of coordinates when you start doing quantum mechanics; if you rotate the spin vector of one particle by 360 degrees relative to the other, their wave functions destructively interfere, so the actual state of the system gets rotated only 180 degrees, and you need another full 360 degrees to get constructive interference again.

As a crude analogy, you can imagine the spin state as an arrow tip that rotates attached to the edge of a Möbius strip, so a 360 degree rotation flips its direction while 720 degrees aligns it back with itself. This is what physicists mean when they talk about SU(2) symmetry and double covers of the rotation group (although in full generality spin transforms under the double covers of the Poncaire group)

Physicsfags fucked up by choosing the words "spin" and "color"

>>16825554 (OP)
It's just a property of a field. Just like mass, charge, position, velocity. It's just that it's not something you encounter with your senses.

How would you explain to someone what is velocity without a notion of position and time?

>>16830691
>How would you explain to someone what is velocity without a notion of position and time?
obviously it's defined using both of those. I wouldn't put velocity with charge or spacetime, you can derive it from spacetime. That's why spin is confusing to me, you'd think you could derive angular momentum from something moving, but apparently it's just it's own thing like charge, except instead of a scalar it's a spinor

>>16830276
Good point.

>>16825554 (OP)
Nothing 'spins'. It is just a word used to describe a property that has no relation to 'spinning'.
When you see the word 'spin' just read it as 'foob' or some other made up word, which works just as well.
>why did they use spin?
Fuck knows. Jews are mentally-ill. Probably 1st goy word the dirty jew thought of.
>IT ISN'T 'SPIN' BECAUSE NOTHING IN THAT 'SPINS'

I saw pauli in his office spinning a fucking menorah

>>16825570
>infinitesimally small
not a thing, you're just too big :)
>zero radius.
they have radius :D
gg ez

>>16830752
It’s called spin because it couples particles carrying it to the electromagnetic field in the same way classical spin angular momentum does and contributes to the Noether charge associated with rotational invariance the same way spin angular momentum (a classical observable ) does.

The fact that it’s not actually associated with a literal rotation and transforms as a spinor rather than a pseudovector were discovered later, but the former two remain true.

I don’t understand why people have difficulty in understanding and imagining spin. Are it those who believe that wave function collapse is an actual physical thing?

>>16831411
What is spin and what happens when you measure a particle?

the name is irrelevant; it is as intrinsic to electrons as mass and charge

property that causes particles to have a magnetic dipole

>>16825556
The tendency to move around itself a particle has regardless of external action

>>16827383
Thank you

god was like "ah fuck none of this works if electrons aren't little magnets", and then added spin

>>16825554 (OP)
At a certain point it gets too frustrating trying to visualize what intrinsic angular momentum is, and it's more rewarding to think of all the reasons our observable universe requires it.

>>16825554 (OP)
Rotational velocidensity of a particle

>>16830405
How can you know that a particle spins if you can't see it spin

>>16832817
Spin describes a property of the particle that we observe in experiements like Stern Gerlack. It's not a literal ball spinning around

>>16825556
rotation bullshit cuh if you lack eloquent vocab say that lmao

>>16825556
Vectors have an angular component, so vector fields HAVE to carry angular momentum. Simple as.

>>16833013
What? What about vector fields with zero curl? Also fermions aren't described by vector fields as far as I know

>>16825554 (OP)
/sci/ has aspbergers OP they don't understand it. They know n-lab and they know an extremely verbose definition like conformal mappings over special unitary groups under isosymmetry.

I'm not a math graduate but I'm a math hobbyist that's aggressively into it and spin is legitimately one of the strangest things in all of mathematics. Despite being one of the strangest things in all of mathematics it's also the backbone of particle physics and the world around you.

>>16825578
Kek

>>16825554 (OP)
its a moving circle OP its turning on an axis

>>16825554 (OP)
its all coming out by itself based on deviations in the spinner affecting the pi wave which is creating machines from diodes

The answer to this thread is that you can't know what things are, just what they do / how they behave.

>>16833728
its spinning on the ratio basically its circular spin and not angular

>>16825554 (OP)
Subatomic spin is literally just the clockwise or anticlockwise circular polarization energy pulsating between electrical and magnetic field.

>>16825592
>I don't get how a wave in a vector field can become a photon of you go small enough
Because that's literally all a photon is.

>>16825570
Zero radius does not mean we cant pick up a vector coming out of the center of Infinitissimal ball to identify it's orientation

>>16830833
I was gunna say "It has polarity, thus a median orthogonal plane."

I did work with SpaceTime where I took half of either and swapped them, where something like enertia or rotation could exist in a zero timeframe.

There is an India youtuber who does a video on spin that I found much more illuminating than anyone else, alternate explainations with examples etc. I cant find it and its not Jermongal or whatever his name is.