What exactly is "spin"?

Like I said before…I lack the ability to explain this really accurately…
Farsite is far better, as it’s his product I’m really relaying (and probably not terribly well), but he does a very nice job explaining this.

If you drop him a PM, he might be able to explain this better.

But I wasn’t saying it is directly like water or air fluid motion, but instead that this is the closest mental model to use.
Obviously it’s not directly the same, because the spins are in the opposite directions that you would get if it were directly the same.

Isn’t is just a term they’ve applied to a particular quantum state? I’m no physicist, but isn’t it kind of like asking what exactly are “latitude and longitude”? They certainly can be used to correspond to real places but latitude and longitude are just mathematical operations used to identify those places. What they are terms in a mathematical model. A big, nasty mathematical model. Describing them beyond the language of math is pretty difficult because, well, that is where they exist. And translating math into English or any other spoken human language can be pretty difficult.

It’s an actual thing, not just a number. It’s not exactly like a spinning top or planet, but, well…here:

Math without physics strikes me as nonsense. This is a huge topic in itself, much larger than what spin is, and I take a very blunt position, possibly out of ignorance. But I think that mathematics, since it is derived of physics, should always allow itself ot be verified by physics, and therefore can never amount to ‘‘something’’ wholly separate from physical reality. And what I’ve often read (and noticed) is physical theories can, when they’re sound, usually be explained in layman terms. String theory, to illustrate my perspective, does not qualify as a physical theory, because it cannot be verified, and needs all these bizarre hypotheses about physical reality such as coiled up dimensions. That seems like a mathematical ‘thing’.

Spin on the other hand was explained to me in quite simple terms here by Anthem, and as a result I ‘sense’ it. I realize it’s not exactly the same as a planets orbital momentum, expecially because it has to do with fixed states, steps, whereas in the case of macro objects there is a continuum. But with this analogy I can kind of graps the concept. I could also imagine what entanglement would mean if it was applied to orbits of planets around stars or moons around planets - but that is of course strictly hypothetical since no planet or star is of an exactly equal mass. Still, the average persons imagination works quite well in accordance with physics, less so with mathematics… but I’m not sure this means mathematics is ‘deeper’. just more abstract and hence infinitely complicated.

Thanks for clarifying. That’s a bit of a disillusionment of course - quantummechanics always suggests these gigantic possibilities for manipulation of matter, and then it turns out Newton still has the final verdict.

dp.

They apply to a physical state and are corelated in polarity up or down at angle x, hence polarisation of light. Charge etc.

You can filter out some wavelengths by using polarised windows etc. So it is definitively and intimately related, it might not be an exact pictorial representation it’s not possible to tell with light or electrons exactly, but fremions do have half integer spin and they do have angular momentum and we do use the spin to indicate a change from positive to negative charge or polarisation of light etc and the forces which have poles.

wave function goes between 0 and 1/2 in x.

Goes between -1,-1/2,0,1/2 and 1 in an electron, hence spin. And hence the circle is a representation of a wave ie cos sin etc as a cyclic rotation or of 360 as say frequency goes from + to - or we traverse the circle as the charge goes from + to - etc.

en.wikipedia.org/wiki/Fermion


y = Sin(x)

Hi guys.

See arxiv.org/abs/physics/0512265, but they haven’t hit the popular media yet. What they’re saying is that spin is a real rotation. It has to be, the electron really does have angular momentum.

In a nutshell you take a tip from LIGO, which is searching for gravity waves. These are expected to change the length of the arms of the interferometer. Then you say to yourself that a gravity wave is a wave of “spacewarp”, and treat the photon as something similar. It’s an electromagnetic wave in space, but what exactly is “waving”? There’s only space there, so you have to look past the electromagnetic field and say “space”. That means the photon is a wave of spacewarp too. It normally travels laterally at c, but pair production converts a +1022keV photon into an electron and a positron. These aren’t travelling laterally at c, but they have opposite spin, so it is rather like the two opposite eddies that TheStumps mentioned. The spacewarp isn’t travelling laterally at c any more, because it travels through itself. It’s travelling through warped space, so it doesn’t travel in a straight line. Instead it goes round and round.

However when you look into the mathematical details of this, (see cybsoc.org/cybcon2008prog.htm#jw) you find that rotation has to be in two dimensions. The best way to think of it is like the rotation of a steering wheel coupled to the rotation of a smoke ring. With this double rotation, you can no longer define which direction the spin is going. To understand this, think of ordinary spin as flying around the equator. It’s a nice tidy circle with a nice tidy orientation, and you can adjust your flight path to fly from pole to pole. That’s another nice tidy circle with a nice tidy orientation. But if you’re continually adjusting your flight path so that you fly around the earth in a figure-of-eight motion, what direction are you flying in? You can’t really say, because it keeps changing, and for the same reason you can’t really assign a direction to electron spin. However if you flew backwards in the figure-of-eight loop, there is a clear difference. This is why we can distinguish electron spin and positron spin. Here’s a depiction to give you an idea. The dark black line is the figure-of-eight loop, rearranged a little to map out a toroid rather than a sphere:

As for what’s spinning, the electron is made via pair production. You start with light. You can then destroy the electron via annihilation, and the result is light. Basically what’s spinning, is light. It’s all spelled out in layman’s terms in amazon.co.uk/RELATIVITY-Theo … 0956097804. Even a child can understand it.

Interesting Farsight. Not seen it described that way before, I’m not sure how empirically valid it is but then spin is an issue that doesn’t lend well to classical representation, nor is it tidilly represented by maths as such. I’m the last person to think that anyone has really nailed the actuality beyond the equations and there are a million and one formulations. What we end up with is the fact that waves are wave like and adequately described by formulations of angular momentum, and they may change sign or polarity and they may not according to which fermion they are, beyond that it’s very much a matter of interpretaion and ideally philosophical.

No a child can’t understand it, even an adult can’t that’s why it’s called science, most people wouldn’t know there arse from their elbow, even some people in science. And even I to some extent.

That said I’m confused about pair production here? Not sure what you are saying?

Greetings Lord Farsight. Thanks for this long awaited response.
Is it correct to say that light is made into an electron through the mechanism of spin? That’s what I get out of this at first glance. That light is trapped into a self referring path, by splitting in two and revolving around itself, so to speak. Confining it to a more or less set location, making it into something resembling a particle, by inter-inter-interference.

Not sure I agree with that formalisation but it’s a semantic issue anyway light is made out of energy, electrons are energy, thus all particles ultimately decay to photons or energy, even electrons which are themselves “fundamental” fermions. The mathematics of spin are fairly obviously correct within the axioms of maths and science. The interpretational issues are obviously a matter of taste though hence Bohmian, RSM, statistical ensemble, Shut Up, No Really Just STFU (SUNRJSTFU), and Copenhagen and Many worlds etc. Also hence various background dependant hypothesis such as the standard models Higgs, Loop Quantum Gravity, String Hypothesis and the above model by Farsight also I presume hypothetical, or probably based on a reworking of many others hypothesis? Don’t know…

Background independant models like String Theory which is of course made up by maths people for maths people to ponder, and determine a use outside of physics for, or to pass on to M-Theorists also a misnomer who then build an extra level on top of it commonly known as a crock or “Science” with a capital S for Special. :stuck_out_tongue:

References! Names! You can drop many, I have to admit it. I could also drop them. But it’s not fame I’m after, not association with famous people, but to lay bare the simplicity of the mechanism so I can understand it.

I am also in the dark about pair production. This seems to be the mechanism which underlies spin, the method by which light is transformed from a singularity into a duality, and so takes on substance. It could be a metaphor for the entire human condition. The pure body of light, Adam splitting in two becoming a pair and subsequently being bound to matter, revolving around itself, and revolving together around a core. Human interpretation, that’s all it is on whatever level. But how does it happen?

It seems that physics is the art of predicting which state will transform into which. The laws of the universe are understood as A + B => C. But the => itself is never touched upon. Physicists have enough respect for it, reverence even, to understand that this is exactly what needs to be danced around.

spin is the resultant of confined energy and/or movement , within a confined space

yet the proton spins in the hyrogen atom

where there is no electron

not also it’s cause, or at least it’s enabler?

Ah, really? I didn’t realize protons spin. As a unity, or is it also split up?

I think you’ll start to see more of this kind of description. Or at least I hope you will. I’m not sure why it’s been such a big problem, and can only presume it’s because the maths is difficult, as epitomized by “the mystery of the moebius strip” which lasted for 75 years. See ucl.ac.uk/~ucesest/moebius.html and note that the electron depiction is akin to a “moebius doughnut”. It takes two revolutions to return to the original position and oreintation.

It’s like riding a bike, once it clicks it’s incredibly simple. I find that Falaco solitons are very useful for conceptual grasp. Find a swimming pool or a pond, preferably on a sunny windless day. Take two dinner plates, one in each hand. Dip one of the plates halfway into the water, and stroke it gently forward in a paddling motion whilst lifting it clear. You create a “U-tube” double whirlpool that moves slowly forward through the water. Now step to one side and create another one with the other dinner plate, aimed at the first. When the left-hand-side of one double whirlpool is near the right-hand-side of the other, the two opposite whirlpools move closer together. When the left-hand-side of one double whirlpool is near the left-hand-side of the other, the two similar whirlpools move apart. What you’re seeing is a fluid analogy for electromagnetic attraction and repulsion. Now aim two double whirlpools straight at one another, face on. The two double whirlpools meet and merge and are gone with a surprisingly energetic puff of muddy water, which is akin to annihilation.

Pair production is key. It provides the very real scientific evidence that the electron is quite literally “made from light”.

Ouch, Jacob. Please don’t call me “Lord”. Most of this stuff I talk about isn’t my own orginal work, It’s just a simplified version of what’s in peer-reviewed papers that haven’t hit the popular media yet. They tend to get crowded out of mags like New Scientist and kept in the shade because too many editors don’t know much physics and think string theory is “the only game in town”.

Pretty much. The mechanism of spin is geometrical. The photon is a transient alteration to the geometry of space, so when it travels through itself it doesn’t travel in a straight line. Get the wavelength right and make it travel entirely through itself, and it’s trapped in a curved path. Then it’s an electron with spin and angular momentum, and of course mass and charge. Annihilate an electron by chucking a positron at it, and all you get out is two 511keV photons. You don’t get anything else. So whilst an electron doesn’t look like light, light is only thing that’s there.

The geometry here goes all the way back to Maxwell’s On Physical Lines of Force where he talks about a screw mechanism, see: en.wikipedia.org/w/index.php?tit … df&page=53. You can also find a reference to this in Minkowski’s wrench analogy about two pages from the end of Space and Time. The electric field is a “twist field” and the magnetic field is a “turn field” view of the selfsame thing when you move through it. Sounds odd, but the right-hand-rule works rather like shoving a drill bit up into your right fist. It’s got a twist to it, so it turns:

Unfortunately Heaviside reworked Maxwell’s equations and changed them from quarternion to vector form. This reduced the emphasis on rotation and describes “what it does” rather than “what it is”. It’s important to appreciate that the electric field is not something separate to the magnetic field, they’re just two different ways of experiencing the electromagnetic field, (see Jefimenko’s equations) and it really is a spatial distortion. Hence the electromagnetic field-variation of a photon is a distortion too. The sine wave traces out a slope, which means the photon is more like a lemon-like pulse. See arxiv.org/abs/0803.2596 and it’s the “enveloping shape” of figure 2.

Actually New Scientist have run several articles on the issue of string theories lack of evidence. Not even wrong was heavilly featured in that article IIRC Woits refutation of the validity of string theory and also Smolins an ex String Theorists view of the inevitable demise of string theory. I can dredge it out if you want can’t remember which issue it was in was about a year ago. I’ve also seen a brilliant refutation in a paper by a prominent string theory skeptic that pretty much blew the idea out of the water because of it’s background independence, I could find that too, but it’s burried deep in the google.

I agree string theory is mathematical word play and little more than philosophy. As to your hypothesis, all I can say is we shall see.

I agree light is energy and thus everything is technically made up of light that’s obvious and no one would disagree with that. I’m not so sure that pair production reveals anything but an exchange of energy when a photon comes into contact with an atom, in that case that is clearly just the energy of the whole system becoming two pair particles, and is not all that special or remarkable. People often get the faulty impression that the electron absorbs all the photons energy but it is in fact the whole system that changes according to the energy states of its constituents.

It makes as little sense to talk only about a photon electron interaction in an atom as it does to talk about any statistical state as being reflective of just one thing not an ensemble.

One can view New Scientist articles here: newscientist.com/search?quer … =rbpubdate. There is some criticism of string theory, but I read it every week, and I’d say they “plug it” rather than take an impartial view.

You seem to be underestimating the importance of pair production. It’s more than just the energy of the system becoming two pair particles. Yes, the nucleus absorbs some of the incoming photon energy, but it’s so massive the momentum transfer is slight. The bulk of the balance acquires rotational motion at c rather has a linear motion, and the electron and positron are created, along with mass and charge along with spin 1/2, angular momentum, zitterbewegung, etc. This means mass and charge are not fundamental, and that the electron is not point particle. Pair production says so very much, and yet there’s nothing in the textbooks that describes the underlying mechanism. And it isn’t necessarily a photon-nucleus interaction, it can be a photon-photon interaction too, see en.wikipedia.org/wiki/Pair_production. Two bosons create two fermions, or vice versa, because when an electron and positron annihilate, the result is mere light. More interestingly, in proton-antiproton annihilation, the end product isn’t quarks and gluons. There’s various routes, such as the production of neutral pions, which decay into gamma photons in ten to the minus sixteen seconds.

I’m not sure what you mean here. A photon/electron interaction within an atom usually involves the excitation of a bound electron, but nevermind. Note that this isn’t really my hypothesis, it’s mainly a synthesis drawn from papers that tend to go unreported.

Because the overall state of an atom is linked to it’s electrons and protons/neutrons therefore, hence the energy is absorbed by the whole atom.

It isn’t like that, Mr Anderson. Typically the electron and positron fly away from the atom with some considerable velocity. See for example iop.org/activity/education/P … _5442.html which talks about particle tracks: