Why is there so much crackpot physics?

[Reality Check]

IYou cannot create an electric field which does not appear to be a magnetic field when you move through it.

But you can have an electric field only, e.g. if you are at rest w.r.t. an electric charge then there is no magnetic field.

You seem to have the fantasy that treating E and M as separate fields means that there is no electromagnetic field. No one is stating this. What we (and Maxwell and all the physics textbooks!) are stating is that there are two equally valid ways to do treat fields in electromagnetism:

• as electric and magnetic fields or
• as electromagnetic fields.

So it is as delusional to deny the existence of electric and magnetic fields as it would be to deny the existence of electromagnetic fields.

 

[BurntSynapse]

I get the impression that you really, really want that statement---"I wonder if there are unexamined assumptions in the statement of non-4D spacetime"---to make a lightbulb turn on over some physicists' head.

You go far beyond "impression" to me. Impression suggests not going much further than what another says, and impressions are vague, whereas you seem to take these impressions as your interpretation, judge them valid, and then build imaginative narratives around them. I think it a poor substitute for following what another actually says, and they almost become creepy.

For example:

"My gosh, I never thought of that! Nonstandard dimensionality!"

You imagine conversations I would never have, then...

As though you had walked up to a 21-year-old Einstein, whispered "maybe time isn't absolute" into his ear, and thereby enabled him to discover SR.

...you imagine me in situations where I get intimate with Einstein, then...

When you're daydreaming about Einstein...

...you imagine yourself inside my daydreams.

Creepy? ...or one might say a bit odd at the very least.

according to your management plan, "information monopoles" and "four days in one" remain in the "undocumented assumptions cause risk" category forever.

Unless these were assumed by the current theory which has problems, this claim is flatly false. I'm sorry you do not understand that a) hardly any of these concepts are MY management ideas, and b) there is never an objection non-existent assumptions like these examples.

I've no objection to real criticism, but attacking "information monopoles" and "four days in one" which you invented is only good for illustrating fallacious reasoning, i.e.: the straw man fallacy. (Attacking a position different, and usually weaker than the best argument of an opponent.)

So, nonstandard dimensions. Yes, for crying out loud, lots of people have thought carefully about the meaning of dimensions.

The number of people and their level of effort is irrelevant if they lack critical input; In particular, the knowledge of how to think about such things.

Including students who read the GR textbook (MTW) I used as an undergrad, which has an extensive discussion of dimensions and what they mean, which you seem to ignore in your quest to apply "risk management" to the risk of "people failing to question assumptions about spacetime" no matter how many people have questioned assumptions about spacetime.

Given the derogatory dismissal of technical terms based on how you imagine they "sound in management-ese" I consider you unqualified to judge, and uninterested in becoming qualified to judge the appropriateness of risk management application in any non-trivial area.

OTOH, I would be delighted to have you prove me wrong by demonstrating some interest in understanding my position. At least you could offer criticism that is helpful: instead of making correct claims that are irrelevant, for example: claiming "for crying out loud, lots of people have thought carefully", when their care is not in question...at all.

Nobody has found a good idea in fractal dimensions, BurntS. Nobody. Why not? Is it because the idea is useless

Perhaps you're right, but I would respectfully ask for evidence that reformulation of fundamental physics since Heaviside has occurred using the best, most modern topological and fractal tools.

Can you provide evidence this reformulation has been considered and either performed or rejected for good reason?

 

[ben m]

I think it a poor substitute for following what another actually says, and they almost become creepy.

I have done my best to understand what you're saying. You are doing a poor job of explaining it. The scenarios I'm positing are meant to be opportunities to clarify. They're prompts, attempting to get you to reconsider your ideas ("Aha, when you put it into that example, might not work.") or to diagnose my misimpressions ("Aha, having read your scenario I see where you misunderstand process concepts. Maybe this will help ..."). It's pretty standard Socratic method, I thought.

...you imagine me in situations where I get intimate with Einstein, then...

Is the situation I drew up not a reasonable representation of how a risk-manager would have "managed" the SR revolution? If not, explain how not.

I've no objection to real criticism, but attacking "information monopoles" and "four days in one" which you invented is only good for illustrating fallacious reasoning, i.e.: the straw man fallacy. (Attacking a position different, and usually weaker than the best argument of an opponent.)

Sorry, I was hoping you'd explain. Why is "non-integer dimensions" an important neglected point in need of risk-manager documentation, but "information monopoles" not? Can you walk me through it? Use the distinction to illustrate your method for identifying sources of risk.

Perhaps you're right, but I would respectfully ask for evidence that reformulation of fundamental physics since Heaviside has occurred using the best, most modern topological and fractal tools.

Can you invent a concrete scenario, just for illustration purposes, in which "the reformulation of fundamental physics" is not done with modern topological tools? Are you concerned that math-department topologists developed a bunch of tools, which physicists never learned about at all? Are you concerned that Heaviside wrote down some 19th-century math, and Schwinger just looked at Heaviside's paper and said "OK, I'll keep using that" and didn't apply his 1950s math skills at all? What are we talking about? Explain.

 

[Perpetual Student]

...
...

Perhaps you're right, but I would respectfully ask for evidence that reformulation of fundamental physics since Heaviside has occurred using the best, most modern topological and fractal tools.

Can you provide evidence this reformulation has been considered and either performed or rejected for good reason?

It's with this sort of question that you compromise your credibility as a professional.
Do your really think it's possible to summarize the ongoing research of tens of thousands of physicists and mathematicians throughout the world continuing for a hundred years since Heaviside -- in order to answer such a question? The fact of the matter is that physicists and mathematicians throughout the world have been striving to develop optimal mathematical tools (topological, fractal or otherwise) on an ongoing basis. That's what they do!
Your question is both naïve and demeaning.

 

[W.D.Clinger]

Perhaps you're right, but I would respectfully ask for evidence that reformulation of fundamental physics since Heaviside has occurred using the best, most modern topological and fractal tools.

Can you provide evidence this reformulation has been considered and either performed or rejected for good reason?

As quite a few people have been trying to explain to you, the Maxwell-Heaviside equations were reformulated using vector methods (late 19th century), reformulated again using what was then called absolute differential calculus (Einstein, 1916), and are now taught (in advanced courses) using modern differential geometry. Even casual perusal of the references we have cited (e.g. Jackson, MTW) would provide the evidence you claim to seek.

I have done my best to understand what you're saying. You are doing a poor job of explaining it.

Agreed. BurntSynapse has put a lot more effort into rationalizing his failures to explain the risks he perceives than he has put into his explanations of those risks.

Can you invent a concrete scenario, just for illustration purposes, in which "the reformulation of fundamental physics" is not done with modern topological tools? Are you concerned that math-department topologists developed a bunch of tools, which physicists never learned about at all? Are you concerned that Heaviside wrote down some 19th-century math, and Schwinger just looked at Heaviside's paper and said "OK, I'll keep using that" and didn't apply his 1950s math skills at all? What are we talking about? Explain.

 

[Farsight]

To be clear I'm not suggesting magnetic monopoles do exist. Unlike unicorns and fairies though, they are predicted by some physical theories (as topological defects in cosmology for example), are explained away by other physical theories that are well motivated for other reasons (inflation) and would arguably make Maxwell's equations more symmetric.

They’ve been predicted for a long time now, edd. It’s like a hundred years, more if you go back to “effluvia”. That sounds like phlogiston, doesn’t it?

An electron has an electric monopole (charge) and a magnetic dipole moment. It's not exactly symmetric in that respect in an interchange of electricity and magnetism. However, Maxwell's equations do show a remarkable symmetry between electricity and magnetism (which is what in the absence of electric and magnetic charges allows electromagnetic waves to pop out so easily, of course).

Fair enough. But I have to say “an electron has an electric monopole” is just a figure of speech that arises from E and B are separate fields thinking. An electron and a positron can move linearly together, and they can circle each other too. There are no charged particles which only move linearly together. There are no particles which have electric fields only. Hence charged particles aren’t really “electric monopoles”. Hence it’s misguided to think magnetic monopoles may exist.

edit: I also meant to mention the neat argument by Dirac about the existence of monopoles and the implied quantisation of electric charge - http://en.wikipedia.org/wiki/Magnetic_monopole#Dirac.27s_quantization , not least as if Dirac of all people is considering magnetic monopoles you might want to sit up and think that they are not completely ruled out by Maxwell.

You should read that section and pay attention to the wavefunction going round the equator. Think about it going over the poles too. That apart, having read a bit about Dirac, I have to say I think he was lucky to get credit for predicting the positron. The Dirac sea, the holes, the negative energy, they’re all very different to the positron having the opposite chirality. It’s as if he shifted his position in response to experimental results.

That symmetry (broken in practice by prescribing the lack of magnetic monopoles when traditionally writing them down) is exactly what should make you realise that there isn't anything truly fundamental to classical electromagnetism and the unification of the E and B fields into one that precludes the existence of magnetic monopoles.

There is, edd. For a magnetic monopole to exist, a region of space would have to be rotating freely, like a roller-bearing. Space just isn’t like that. Instead you get frame-dragging. That’s essentially what the electromagnetic field is. So the magnetic monopole contradicts the whole ethos of what electromagnetism is all about.

It's patently wrong to say that a charged particle has an electromagnetic and not an electric charge.

I’m sorry edd, but there are no charged particles which only move linearly together. It’s that simple.

It's why in the traditional formulation
∇E= ρ_e (edit: well, give or take a factor of ε₀)
and
∇B = 0 .
You may have a philosophical reason to not use the E and B notations, but I use them here because they're what most other readers will be most familiar with, and they make the connection between the charge and the electric part of the field abundantly clear, and however you might wish to write down a description of the behaviour of the electromagnetic field the mathematical statement remains the same.

All the traditional formulations and all the mathematical statements in the world isn’t going to give you charged particles which only move linearly together. Because charge is topological. Not magic.

 

[Farsight]

What all of us save one know is much closer to this (do feel free to ask around):

1. You claimed that the AB effect was first described in a paper on classical electromagnetism, namely Ehrenberg and Siday's 1949 paper "The Refractive Index in Electron Optics and the Principles of Dynamics"....

It's about the refractive index. And optics. There's not a Bra-ket in sight.

...Well, blow me down. E+S have calculated the effect of the solenoid's field on interference fringes generated by electrons! That's pretty quantum mechanical, n'est-ce pas?

And again I refer you to Aptly-named Aharonov-Bohm effect has a classical analogue, long history. Classical physics describes waves. See this.

"It is interesting to note that the reasoning of Ehrenberg and Siday was based almost wholly on classical mechanics".

So no, it's a classical paper. Some refer to it as a semi-classical paper, but the word classical is still in there. Oh and by the way, you might want to have a word with ben m, who thinks the electron is a point particle.

Now, are you ready to tackle those two questions?

Tackle? Those questions are trivia:

(1) What is the Aharonov-Bohm effect?
(2) How is it detected experimentally?

The answers are:

(1) A shift in electron diffraction fringes
(2) You do a double-slit experiment with electrons, then turn on the solenoid.

 

[Farsight]

But you can have an electric field only, e.g. if you are at rest w.r.t. an electric charge then there is no magnetic field.

Throw a charged particle through that electric field only. Watch it loop around. So much for your electric field only.

You seem to have the fantasy that treating E and M as separate fields means that there is no electromagnetic field.

Oh you have got to be kidding me. How many times have I said the field concerned is the electromagnetic field. Electromagnetic field interactions result in linear and/or rotational force.

No one is stating this. What we (and Maxwell and all the physics textbooks!) are stating is that there are two equally valid ways to do treat fields in electromagnetism:

• as electric and magnetic fields or
• as electromagnetic fields.

So it is as delusional to deny the existence of electric and magnetic fields as it would be to deny the existence of electromagnetic fields.

No, they aren't equally valid. You cannot have an electric field that is not in some situation perceived as a magnetic field, and vice versa. Maxwell unified electricity and magnetism. Minkowski said the field. Just how many times do I have to give that quote before you stop dismissing what I'm telling you as some kind of delusional fantasy?

"In the description of the field caused by the electron itself, then it will appear that the division of the field into electric and magnetic forces is a relative one with respect to the time-axis assumed; the two forces considered together can most vividly be described by a certain analogy to the force-screw in mechanics; the analogy is, however, imperfect".

 

[edd]

Farsight - you have realised that things often follow curved trajectories even when the field generating the force upon them has zero curl? I can write down a looping path for something moving under purely electrostatic forces, just as I can write down an orbit in a big standard gravitational field.

 

[Farsight]

Farsight - you have realised that things often follow curved trajectories even when the field generating the force upon them has zero curl? I can write down a looping path for something moving under purely electrostatic forces, just as I can write down an orbit in a big standard gravitational field.

Sure I do edd. But we all know that electromagnetic rotational motion is distinct from what we see in gravity. See for example this picture of an electron beam in a magnetic field from David Pace's website. You get the same kind of motion when you throw an electron through a solenoid. The thing we call a magnetic field is that remnant of two sets of electromagnetic fields that don't quite cancel because the electrons are moving through the wire and the metal ions aren't. The linear forces cancel, but the rotational forces don't.

 

[W.D.Clinger]

With my highlighting:

Farsight - you have realised that things often follow curved trajectories even when the field generating the force upon them has zero curl? I can write down a looping path for something moving under purely electrostatic forces, just as I can write down an orbit in a big standard gravitational field.

Sure I do edd. But we all know that electromagnetic rotational motion is distinct from what we see in gravity. See for example this picture of an electron beam in a magnetic field from David Pace's website. You get the same kind of motion when you throw an electron through a solenoid. The thing we call a magnetic field is that remnant of two sets of electromagnetic fields that don't quite cancel because the electrons are moving through the wire and the metal ions aren't. The linear forces cancel, but the rotational forces don't.

Farsight must not know what "purely electrostatic" means, but we may see some progress here. Just a few days ago, Farsight was denying the reality of magnetic fields, and accusing anyone who even mentioned magnetic fields of being totally ignorant of electromagnetism. Farsight is now speaking of magnetic fields himself, and recommending web pages that not only speak of magnetic fields but show their effect on electron beams.

Farsight doesn't yet understand that a purely electrostatic field, with zero magnetic field, can produce curved or even circular motion in exactly the same way that gravitational fields produce curved or circular motion. (His explicit denial of that possibility is one of the things I highlighted.)

 

[ctamblyn]

It's about the refractive index. And optics.

It's about the theoretical discovery of a phenomenon which would not occur if electrons were classical particles. It treats the electrons as waves (ETA) as well as particles (/ETA)... now, what's that theory that does that again? Hmmm. It's certainly not classical electrodynamics.

There's not a Bra-ket in sight.

Keep digging, by all means. If you'd ever studied QM, you'd surely know that QM doesn't depend upon Dirac's bra-ket notation (in fact, in the early days of QM there was no such thing).

In fact, if you'd ever studied QM you would probably have started by learning the single-particle nonrelativistic Schrödinger equation, which would be sufficient mathematical apparatus to deal with the hydrogen spectrum, the two-slit experiment and several other simple phenomena - including, of course, the AB effect, as demonstrated by the fact that Aharonov and Bohm's 1959 paper does not use Dirac's notation either, though it had been known for twenty years by then.

You quote Berry's article again:

...
"It is interesting to note that the reasoning of Ehrenberg and Siday was based almost wholly on classical mechanics".

You keep neglecting the highlighted word above (presumably because it is the very thing which disproves you), but even if Berry had supported your position (he doesn't, as your quote itself demonstrates), it would have been irrelevant since the original paper itself contradicts you.

...the word classical is still in there...

Only once in the original paper does the word "classical" appear, on page 15 if you're following along at home. Why don't we take a look at the context?

...
At the same time the refractive index of geometrical optics becomes inversely proportional to the wavelengths.

This description [i.e. the analysis so far] is based purely on classical physics. To complete the description of any electron-optical phenomenon it is necessary to introduce the absolute size of the wavelength. In the case of an isotropic medium, in the absence of a magnetic vector potential, the well-known formula of L. de Broglie

λ₀ = h/mv _ ......(35)​

is valid.
...

They have just finished treating the situation classically and are about to embark upon a wave-mechanical (quantum) analysis, beginning with de Broglie's equation for the quantum-mechanical wavelength of the electron. (ETA) And it is only because they did this that they were able to predict what we now call the AB effect, as they make clear in their paper.

Tackle? Those questions are trivia:

(1) What is the Aharonov-Bohm effect?
(2) How is it detected experimentally?

The answers are:

(1) A shift in electron diffraction fringes
(2) You do a double-slit experiment with electrons, then turn on the solenoid.

Correct (or near enough), and that is the exact phenomenon that Ehrenberg and Siday described at the end of their paper.

Since your "argument" amounts to no more than "I found the word classical in there somewhere," I think we just wrapped up.

 

[edd]

Oops. Obviously I meant 'bog standard' back then but my phone thought it knew better.

 

[ctamblyn]

With my highlighting:


Farsight must not know what "purely electrostatic" means, but we may see some progress here. Just a few days ago, Farsight was denying the reality of magnetic fields, and accusing anyone who even mentioned magnetic fields of being totally ignorant of electromagnetism. Farsight is now speaking of magnetic fields himself, and recommending web pages that not only speak of magnetic fields but show their effect on electron beams.

Farsight doesn't yet understand that a purely electrostatic field, with zero magnetic field, can produce curved or even circular motion in exactly the same way that gravitational fields produce curved or circular motion. (His explicit denial of that possibility is one of the things I highlighted.)

It looks to me like Farsight believes that the very fact that things can move in curved trajectories in a purely electrostatic field is somehow evidence that the field is not "really" purely electric. I think it is a confusion beyond repair, personally, but I could be wrong. Edd's comparison with the gravitational case may help, or not.

 

[ctamblyn]

Tackle? Those questions are trivia:

(1) What is the Aharonov-Bohm effect?
(2) How is it detected experimentally?

The answers are:

(1) A shift in electron diffraction fringes
(2) You do a double-slit experiment with electrons, then turn on the solenoid.

Oh, and I take it that your answer to (1) is an admission that your remark about interference patterns at the bottom of this post was a mistake. It's a start.

 

[Farsight]

It looks to me like Farsight believes that the very fact that things can move in curved trajectories in a purely electrostatic field is somehow evidence that the field is not "really" purely electric. I think it is a confusion beyond repair, personally, but I could be wrong. Edd's comparison with the gravitational case may help, or not.

I'm not confused at all. See this picture I linked to above? Note the helical path? You don't get that sort of motion from electrostatics. It's a helical path. Because of the screw nature of electromagnetism. You know, the thing Maxwell and Minkowski talked about?

You keep neglecting the highlighted word above (presumably because it is the very thing which disproves you),

I haven't neglected it, I gave the full quote some days ago. You're flogging a dead horse, it says classical, you've lost this argument, stop clutching at straws, move on.

Oh, and I take it that your answer to (1) is an admission that your remark about interference patterns at the bottom of this post was a mistake. It's a start.

No. Michelson and Morley worked with an interferometer.

You know ct, it's pretty clear that you're inventing disproofs that don't exist and admissions of error that don't exist either. When you've lost an argument, try not to make it so obvious that you're getting desperate. And please don't get in the way of me educating the guys here about electromagnetism and related matters.

 

[ctamblyn]

I'm not confused at all. See this picture I linked to above? Note the helical path? You don't get that sort of motion from electrostatics. It's a helical path. Because of the screw nature of electromagnetism. You know, the thing Maxwell and Minkowski talked about?

Actually, you're wrong again. You can have a pure electric field that will cause particles to move in helical trajectories (given the right initial conditions). Exercise for the reader: what could the E-field be?

I haven't neglected it, I gave the full quote some days ago.

Without the essential context. ETA: In fact, no you didn't. I just went back and read through your posts, and not once did you quote the passage I just did.

You're flogging a dead horse, it says classical, you've lost this argument, stop clutching at straws, move on.

If Ehrenberg and Siday say "in the case of an isotropic medium, in the absence of a magnetic vector potential, the well-known formula of L. de Broglie...is valid" and you honestly think they're talking about classical electrodynamics, it follows that you do not understand quantum or classical electrodynamics, at all.

ETA: You added this in an edit:

You know ct, it's pretty clear that you're inventing disproofs that don't exist and admissions of error that don't exist either. When you've lost an argument, try not to make it so obvious that you're getting desperate. And please don't get in the way of me educating the guys here about electromagnetism and related matters.

I'll let the audience decide whether your accusation of dishonesty is accurate, or perhaps misplaced.

 

[Farsight]

Oh change the record, ctamblyn.

Right, I'm off. Meanwhile ctamblyn will entertain you with fables about a "pure electric field", and about the multiverse. Woo!

 

[ctamblyn]

Oh change the record, ctamblyn.

Right, I'm off. Meanwhile ctamblyn will entertain you with fables about a "pure electric field", and about the multiverse. Woo!

For the record, Farsight, I have not once said that a multiverse theory is true. I have even indicated (e.g. in the "Is the Universe Unnatural" thread) that my position is one of agnosticism towards the whole issue. What I'm objecting to are your fallacious, misinformed and spurious arguments relating to running couplings.

As to the issue of what a field is, well, you're welcome to your personal definitions. It just turns out that the concept you label "field" is of no interest, while the standard physics definition is very useful indeed.

 

[W.D.Clinger]

I'm not confused at all. See this picture I linked to above? Note the helical path? You don't get that sort of motion from electrostatics. It's a helical path. Because of the screw nature of electromagnetism. You know, the thing Maxwell and Minkowski talked about?

Actually, you're wrong again. You can have a pure electric field that will cause particles to move in helical trajectories (given the right initial conditions). Exercise for the reader: what could the E-field be?

The electric field of a uniformly charged rod would do the trick. The electric field intensity of a point charge is proportional to 1/r²; integrating (summing) over the point charges of an infinitely long rod yields an electric field intensity proportional to 1/r, where r is distance from the rod, and that approximation is close enough to use for finite rods when r is much less than the distance to an endpoint. Inject an oppositely charged particle into that electric field whose velocity components in the plane perpendicular to the rod are exactly what is needed for the particle to orbit the rod, and give it some velocity parallel to the rod as well so its path will become a helix instead of a circle.

Meanwhile ctamblyn will entertain you with fables about a "pure electric field",

During the last half of the twentieth century, most oscilloscopes used electrostatic deflection (pure electric fields).