What exactly is "spin"?

Farsight says that if a particle is disbanded, it results in light.
Is that true or not?

I don’t know of the dark matter debate, but I’m interested. How would general relativity do away with the need for it?

Ah, PhysBang. My very own personal troll. I’ve missed you.

I never refuse explanations PhysBang, you know that. See the post below for an explanation.

I’ve explained it in very simple terms. It’s actually trivial. It’s fully in line with Einstein’s GR, and you have no counter-argument. Your demand for a fully-worked mathematical is merely a diversionary smokescreen. I won’t give it because it would take me too long and readers won’t understand it anyway.

Most people have heard of Minkowski’s Space and Time paper from 1908. They’re aware that it constituted an important development for special relativity. However very few people notice a little paragraph two pages from the back:

“Then in the description of the field produced by the electron we see that the separation of the field into electric and magnetic force is a relative one with regard to the underlying time axis; the most perspicuous way of describing the two forces together is on a certain analogy with the wrench in mechanics, though the analogy is not complete”.

A wrench turns a bolt which has a screw thread. You turn a screw and it moves forward. Or you can use a pump-action screwdriver to convert linear motion into rotational motion. This is why alternators and generators and electric motors work, and you can find a reference to a screw mechanism in Maxwell’s On Physical Lines of Force. See en.wikipedia.org/wiki/File:On_Ph … _Force.pdf and note this line on the wikipedia page 53:

"A motion of translation along an axis cannot produce a rotation about that axis unless it meets with some special mechanism, like that of a screw "

Look at the page heading and see where it says The Theory of Molecular Vortices. Maxwell didn’t get this right, but it turns out he wasn’t far off. Once you understand the dualism of the electromagnetic field, it’s horribly simple: it’s a “twist/turn” field with an underlying curved spatial geometry.

Think about a vertical column of electrons and try to envisage the surrounding electromagnetic field. If you are motionless with respect to this, you’ll see the electric aspect of the field, with radial “electric field” lines and linear motion along them. If however you move downwards past the column of electrons, you’ll see the magnetic aspect of the field, with orbital “magnetic field” lines and rotational motion around them. Your downward motion is relative, so the magnetic aspect is visible if you are motionless and the electrons are moving upwards, as per a current in a wire and the right-hand-rule:

Note that it’s one field, it’s the electromagnetic field, not separate electric fields and magnetic fields. Jefimenko’s equations are a useful reminder in this respect. The electromagnetic field is a dual entity, there’s only one field there. Moving through an electric field doesn’t cause a magnetic field to be generated, because as Minkowski said, it’s the electromagnetic field, and it exerts force in two ways. It doesn’t actually look like anything, but iron filings on a piece of paper tells you that you can visualize a field. Note though that the iron filings only show you a slice through a “magnetic” field, and you need to see the electromagnetic twist/turn field in three dimensions. You can use a drill bit for this, but a reamer is better. This kind of thing:

Grasp a reamer in your right fist, place your left thumb on the bottom of it, and push upwards. It turns. The disposition of the electromagnetic field around a column of electrons is like a reamer. It has an innate twist, and motion through it causes turn. If you imagine a nested family of reamers all centred on the same vertical line, you can get an idea of how the field strength diminishes with distance. Then when you imagine a horizontal slice through the field, it would have a spatial twist like this:

This twist is however in three dimensions, which is why Minkowski said the analogy is not complete. Take a piece of wire and bend it to form a Fibonacci spiral. It is now curved, and resembles one of the lines in the picture above. Now lie the wire flat on your desk and bend in another Fibonacci spiral orthogonal to the first. Your wire is now “curled”. Hence magnetic curl. In Europe this is called rot, which is short for “rotor”. It’s caused by a frame-dragging effect by a central soliton or more properly “vorton” rotating in two dimensions, like this:

This is a depiction of the electron. It’'s a self-trapped photon. See arxiv.org/abs/physics/0512265 . Note the black line in the depiction, indicating a double-rotation, hence spin ½ . Again we see twist and turn. The electron is often called an elementary or fundamental particle, but it isn’t. You can create an electron via pair production:

It’s like throwing a wave at an obstruction and seeing two opposite eddies coming out. These affect the surrounding space - something like a rotating electric floor polisher on a thin rubber sheet, but in three dimensions. The result is an electromagnetic field. Conservation of charge is rather like conservation of angular momentum - if you were up in space in a spacesuit and you manhandled a satellite to give it a rotation, you’d find yourself counter-rotating.

The reason why the photon self-traps at 511keV is straighforward. An electromagnetic field is a twist/turn field, and it is a spatial geometry. A light wave is an electromagnetic field variation, which is actually a pulse of “twist/turn”. It’s best to think in terms of a pulse of spacewarp in a cubic lattice. Imagine a lemon-shaped extensional distortion of the lattice in the centre - a bulge like a swell wave on the ocean surface, but symmetrical top and bottom because this is in a bulk. The archetypal sinusoidal electromagnetic wave is telling you the slope of the horizontal lattice lines. Around a lemon-like shape, the slope rises to a maximum a quarter-way along the lemon, goes back to zero at the top of the lemon, then falls to a negative maximum three-quarters along, then goes to zero again. If this pulse of spacewarp encounters another pulse of spacewarp, it’s moving through warped space, and so its path changes. If this causes it to encounter more spacewarp, its path will change further. That black line in the depiction above is telling you that here we have spacewarp that is travelling entirely through itself. At 511keV, where the degree of spacewarp is just right. The path keeps changing, and as a result the photon energy/momentum is now travelling in a circular path. Hence angular momentum and magnetic dipole moment with a g-factor of 2.0023.

But we don’t call it a photon any more. We call it an electron.

Someone has to be there to make sure that people are not grossly mislead about contemporary physics.

You appear to have cut and pasted a post from another forum, a forum where many people have pointed out that you have no explanation.

But let’s humour you. How does Minkowski’s mathematical description of electromagnetic phenomena in the paper you cite produce anything like the diagram you use? Since Minkowski’s paper is a mathematics paper, please show the mathematics. (If you can’t, then your citation appears to be dishonest.)

Show us directly how the measurements of dark matter done by all those astronomers are wrong. Don’t insult the intelligence of people here. Since you were never able to answer this question in front of a board full of astronomers, it merely looks like dishonesty when you refuse to answer the question now.

The mathematics doesn’t show it, PhysBang. The right hand rule does, along with the fact that the electromagnetic field is one field, and works via a screw mechanism, or a wrench if you prefer, just like Maxwell and Minkowski said.

As for dark matter, as I’ve pointed out previously, astronomers haven’t measured any. What they’ve actually measured, is gravitational anomalies. One merely has to read what Einstein actually said in The Foundation of The General Theory of Relativity (3.6 Mbytes) to see the fallacy of the dark matter hypothesis. On page 185 he says “the energy of the gravitational field shall act gravitatively in the same way as any other kind of energy”. As we all know, a gravitational field isn’t made of dark matter. You don’t look at a gravitational field and say “Ah, this causes gravity, there must be dark matter particles there”. The dark matter hypothesis is based on the presumption that space is homogeneous, which is contrary to general relativity:

“According to this theory the metrical qualities of the continuum of space-time differ in the environment of different points of space-time, and are partly conditioned by the matter existing outside of the territory under consideration. This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that ‘empty space’ in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials gμν),”

The space around a galaxy isn’t homogeneous because space expands between the galaxies but not within, as per the raisins-in-the-cake analogy. Hence a galaxy is surrounded by a halo of inhomogeneous space. A gravitational field is a region of inhomogeneous space. So galaxies have an extra gravitational field component, but it’s caused by differential expansion, not by dark matter. Which is why the CDMS collaboration can’t find dark matter.

Simple.

Any rule that describes how things move will be a rule that one can describe mathematically. It is well known that Maxwell and Minkowski, like all serious physicists, both used mathematics to describe electromagnetism. Additionally, if you knew anything about mathematical physics, you would know that a “wrench” does not always produce a rotation. So either show how Maxwell and Minkowski actually produce your particular picture or admit that there is no support for your position and move on.

If this is the case, then show us exactly how taking this into account removes the gravitational anomaly. Remember, people have been measuring dark matter in galaxies for decades now, so there are lots of papers for you to choose from for a good example of a single mistake in this area. If you have never actually done this kind of calculation and comparison with the actual work of astronomers, then it seems that you are simply not telling the truth.

The measurement of dark matter in galaxies and galaxy clusters make no assumption that space is homogeneous. You have either bought someone else’s mistake or lie or this untruth is one you have created. We know that the dark matter measurements are not based on an assumption of homogeneity because they are measurements of galaxies, objects which are concentrations of matter. Of course, Farsight, you can try to actually find a paper where this assumption is shown.

But this is still nothing but a distraction away from how physicists do their work: with measurements.

No the scientifc evidence shows it, the right hand rule and the relative motion, not the mathematics. And people have been measuring gravitational anomalies for decades. That’s why it’s the dark matter hypothesis. Nobody can find any dark matter, remember? And see the FLRW metric and note where it says The FLRW metric starts with the assumption of homogeneity and isotropy of space. Now what did Einstein say? Neither homogeneous nor isotropic. Simple.

Except that

a) The FLRW model is not used to measure the amount of dark matter from galaxy rotation curves. You should know this, as probably a dozen people on the internet have pointed this out to you. And this is something that anyone who says anything about dark matter physics should know. So apparently you haven’t done any research and you are dishonest about the evidence for your theory. Address the galaxy rotation curves.
b) Einstein’s personal, preferred model was a special case of the FLRW model. Are you saying that Einstein was wrong about his own theory?

Dark matter isn’t being measured. Rotation curves are being measured. By your logic somebody could advance tiny dancing angels as a causative hypothesis, and assert that tiny dancing angels are being measured. They’re not.

No, Einstein wasn’t wrong. He said space was “neither homogeneous nor isotropic”. But “The Friedmann–Lemaître–Robertson–Walker (FLRW) metric is an exact solution of Einstein’s field equations of general relativity” and it "starts with the assumption of homogeneity and isotropy of space". Something got dropped somewhere along the line. Inhomogeneous space has been replaced by homogeneous space, and the result is the dark matter hypothesis, along with people promoting one hypothesis above alternatives in an attempt to establish it as a consensus.

If someone showed how to measure a parameter of tiny dancing angels with these rotation curves, then, yes, tiny dancing angels would be measured. This is how physics works. Whether or not we would believe in tiny dancing angels is another matter. However, even tiny dancing angels is a better answer than you have given so far because your answer not only doesn’t provide an explanation with the possibility of measurement, you are actively contradicting the use of general relativity in the actual scientific papers. You are pursuing your personal fantasy and demanding not only that others believe it, but that they disregard every scientific paper in favour of your fantasy.

As per usual, you did not answer the relevant question. Do you think that Einstein was wrong to prefer a homogeneous model of the universe?

He means that measuring the distance between balls in a cube of balls isn’t measuring the balls, but instead measuring the distance between them.
If, now, you could not see or sense the balls, but could only sense where passing through them was not possible and where it was; using this as a measure of “between” area of the balls…shrug more or less like sonar in a sub…then you would have no direct ability to declare what the objects where the sensors do not pass through are exactly…you would not be able to say they are balls or dancer statues.
For all anyone knows, they could be dancer statues in balls…or boxes with obtuse spin that results in a rather rounded feedback to the sensors.
shrug

The point is that the gaps are measured…not the objects.
By reduction, we assume the measure of the objects.

But it’s called dark for a reason, and that reason is that we simply don’t truly know what that stuff is.
For all we know, there could be 500 different classifications of matter within what we call “dark” matter today.

Did you mean these question for me?

I do not know what it means for a particle to be “disbanded”. There are many interactions that can take place where particles are destroyed and other particles are created. Sometimes this involves photons. Every explanation of how this happens involves specific predictions and mathematical descriptions about how these events happen.

I do not know how general relativity would do away with dark matter, this is an imagining of Farsight, not a supposition of physics. Every measurement of dark matter that I know of involves either scales where general relativity is not supposed to have a significantly different measurement from Newtonian physics or uses general relativity directly. According to astronomers, it is general relativity that suggests that dark matter exists.

Yes, there were intended for you… thanks for trying to answer. But… this is all extremely vague, not really anything of substance. Farsight may be lying, but so far I have to just take his critics at their words. They might be totally in the dark. Which is how it appears to me, because all I get is references to links and comments like ‘there are many ways things happen. But I won’t get into the mathematical details.’ Vaguer than vague.

Anyway, I was under the impression that it is the rotation of galaxies suggest a much greater mass that what is measured, that suggests dark matter. I always found this a bit of a stretch. I am open to the suggestion there is a more elegant solution.

I hope you note that Farsight is also vague on mathematical details. He is someone that, in his own words, refuses to develop mathematical details.

The reason that my answers may be a bit vague is because Farsight is literally so wrong that he is not really talking about physics. When you ask a question about what alternatives to his theories could be, one can only point to the work that actual physicists do because Farsight refuses to actually produce specific predictions of his theory. If one criticizes Farsight on a particular point, he dodges the questions by discussing something else or by claiming that he means something else. He can’t be pinned down because there is really no content to his theory.

I ask him about the rotation curves of galaxies because that is one specific prediction that he has made (perhaps the only one). He is saying that if one calculated the rotation curves of galaxies using general relativity, then there would be no need for the hypothesis of dark matter. Now he has never actually shown how to do this (and there are many papers that actually do this calculation and show that we still need to hypothesize dark matter). That Farsight refuses to support the one prediction he has ever made is a bad sign for his ability to produce a real physical theory.

The rotation curves of most galaxies suggests that the visible part of galaxies are surrounded by a much larger distribution of mass. So too does the way that light bends around galaxies. So too do the orbits of galaxies around each other. So too does the bending of light around groups of galaxies.

Looking at the way that galaxies form into clusters in general suggests that there is some sort of dark matter. So too does the behaviour of particles in the early universe.

These are all research projects with a lot of physicists and astronomers making careful observations and calculations. Almost all of these scientists use general relativity. Despite this, Farsight claims that if we used general relativity correctly, we would not have a need for dark matter. So Farsight is saying that all of these scientists are wrong, though he will not show anyone exactly how these scientists are wrong. Even on a message board with dozens of professional astronomers and astrophysicists, Farsight could not produce the relevant calculations.

Farsight does seem good at offering confident statements. Unfortunately, science is often not as confident as we would wish it to be. Additionally, Farsight never delivers on the evidence that his confidence suggests.

PhysBang = correct.

Farsights point is that Einsteins statement that space is not homogenous does away with the necessity of dark matter.

The argument for dark matter is curiously similar to the argument for God. There’s a phenomenon we can’t account for, so we posit an invisible entity to account for it. That entity is subsequently proven by measuring the phenomenon again, and concluding it is consistent with itself. I don’t see any proof anywhere except that we’re lacking knowledge about the relation between gravity and mass on a large scale. Given that on a very small scale, certain laws do no longer apply, shouldn’t the possibility for a similar discontinuity on the other end of the scale at least be considered?

Yes, but what does that mean?

Einstein believed that space on the large-scale average was homogeneous. We know that because he endorsed a cosmological model in which this was the case both before and after he made the claim that Farsight quotes. So what did Einstein mean when he said that space is not homogeneous? Well, he meant pretty much what he said afterwards, which is that in order to explain gravity, we have to look to the distribution of matter in spacetime and use this to determine the geometry of spacetime. (And this is what every relativistic cosmological model does and what every astronomer who measures dark matter using relativistic means does also.)

But what does Farsight mean when he says that inhomogeneous space will do away with the need for dark matter? Nobody knows. I suspect not even Farsight knows. If we could see an actual calculation of how to calculate a galaxy rotation curve “the Farsight way” then we would have an idea of what he means. But unlike every scientific paper on dark matter, Farsight refuses to actually demonstrate the relationship between measurements of gravitational phenomena and dark matter.

Physics is more than the ability to state things confidently. Physics involves the ability to make claims about physical systems that we can either use in application or that we can support with observations that include measurements. Farsight has never made such a claim.

There is a difference between the argument for dark matter and the argument for god: measurement evidence and the properties of dark matter. While god can have any properties, dark matter cannot. And we can measure the properties of dark matter in many, many ways. And people do consider the possibility that a change in the way gravity works might change the need for dark matter. So far, these other projects have failed.

Note that Farsight claims that he is not trying to change gravitational theory. He seems to be saying that if people calculated correctly, then there would be no need for dark matter or an alternative to standard gravitational theory. Yet he refuses to demonstrate how to calculate correctly.

I will let Farsight counter these challenges if he feels the need to - dark matter isn’t really the focus of this thread anyway - I think I’ll just order his book and form my judgment based on that.

Didn’t Einstein have had a position on Dark matter himself, by the way? And did he not propose this cosmological constant which now somehow comes back as dark energy, responsible for the expansion of the universe? I know it’s not the same, but the theory of dark matter existed when he was still alive, didn’t it?

If you are interested in physics, I would recommend that you start with more basic books on the subject.

The problem that there might be a matter that cannot be seen was considered since at least the 1930s, but there was no evidence for a need for dark matter until after Einstein’s death.