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Electromagnetism as a Purely Geometric Theory
- rkagerer 1y agoCouldn't get past the robot wall.
- xeonmc 1y agoI recommend https://www.youtube.com/watch?v=Sj_GSBaUE1o https://www.youtube.com/watch?v=Sj_GSBaUE1o instead
- sitkack 1y agohttps://www.researchgate.net/publication/390640631_Electromagnetism_as_a_purely_geometric_theory https://www.researchgate.net/publication/390640631_Electroma... And then I got a bot check on researchgate, first time and I download a lot of papers from them.
- oriel 1y agoAt this point, should failing the test be an indicator of being human, rather than success?
- andyjohnson0 1y ago> Couldn't get past the robot wall. Nothing like that for me. I just clicked the big "article pdf" button at the bottom of the page. Direct link to full pdf: https://iopscience.iop.org/article/10.1088/1742-6596/2987/1/012001/pdf https://iopscience.iop.org/article/10.1088/1742-6596/2987/1/...
- 0hijinks 1y agoLinks to the article and the PDF both are behind this human test. Guess today is the day I learned I'm a robot.
- xeonmc 1y agoRaiden empathizes with you: https://thepunchlineismachismo.com/archives/comic/the-straw-that-broke-the-robocamels-exoskeleton https://thepunchlineismachismo.com/archives/comic/the-straw-...
- Iwan-Zotow 1y ago"bite my shiny metal a$$" kind of robot?
- deleted 1y ago[deleted]
- Roverlord 1y agoWas it by any chance a redirect to 'validate.perfdrive' something or other that then just fails? Freaked me out as it reminded me of the behaviour of those weird search hijackers I haven't seen in a good while.
- ogogmad 1y agoFor people wondering what "geometric" means here, they say: "the electromagnetic field should be derived purely and solely from the properties of the metric tensor". I'm not sure if that's exactly it. Question: Is there any relationship between this and Axiomatic Thermodynamics? I recall that also uses differential geometry.
- philipov 1y agoOkay, so this is another attempt to unify quantum field theory and gravity. By using gravity to get quantum fields, rather than by trying to quantize gravity.
- pdonis 1y agoI don't think so. The paper doesn't talk about gravity at all. It talks about electromagnetism.
- philipov 1y agoIf the paper is attempting to express electromagnetism in terms of the metric tensor, then it is putting it into a form that makes it potentially compatible with gravity, which is also a metric tensor. Quantum theories use a completely different type of math, and trying to express gravity in that way (quantizing gravity) results in a bunch of broken equations. If both systems can be described using differential geometry, that is a step in the direction of unifying the theories, even if it's not a hole-in-one.
- pdonis 1y ago> If the paper is attempting to express electromagnetism in terms of the metric tensor, then it is putting it into a form that makes it potentially compatible with gravity, which is also a metric tensor. But the metric tensor of spacetime, in General Relativity, which is our best current classical theory of gravity, only explains gravity. Gravity, by itself, uses up all of the degrees of freedom in the metric tensor. There aren't any left for electromagnetism or anything else. To get classical electromagnetism, you need to add another, different tensor to your model--a stress-energy tensor with the appropriate properties to describe an electromagnetic field. Of course doing this in standard GR is straightforward and is discussed in GR textbooks; but it does not involve somehow extracting electromagnetism from the metric tensor. It involves describing electromagnetism with the stress-energy tensor, i.e., with different degrees of freedom from the ones that describe gravity.(And if you want to describe the sources of the field, you need to add even more degrees of freedom to the stress-energy tensor to describe charged matter.) The paper does not, as far as I can see, address this issue; the authors don't even appear to be aware that it is an issue. Which makes me extremely skeptical of the paper's entire approach.
- nsoonhui 1y agoForgive my ignorance but isn't this proven to be a dead end? There is this Kaluza Klein theory that proposes EM as the fifth dimension that has been ruled out, and Einstein spent large part of his later years trying to integrate EM into the GR geometric framework, with no success, mainly because he didn't know about strong and weak nuclear force as the other two fundamental force besides EM and gravity.
- phkahler 1y ago"As the electrodynamic force, i.e. the Lorentz force can be related directly to the metrical structure of spacetime, it directly leads to the explanation of the Zitterbewegung phenomenon and quantum mechanical waves as well." Cool because traditional QM wave function waves are not electromagnetic waves even though they seem to be the same thing in a double slit experiment.
- koolala 1y agoWhat makes them different when they perform the same way in a double slit? They act differently at different scales or something else?
- Devilspawn6666 1y agoI think they're referring to quantum wavesfunctions being in configuration space rather than real spacetime.
- molticrystal 1y ago>The Dirac equation can be therefore interpreted as a purely geometric equation, where the mc2 term directly relates to spacetime metric. There is no need to involve any hypothetical Higgs field to explain the particle mass term. What happens to the Higgs field excitation and the Higgs boson, given the experiments confirming their existence? If this paper explains phenomena more effectively, does it require us to reinterpret these findings?
- kanddle 1y agoAny good theory probably needs to explain or reinterpret past phenomenon that has already been proven by experiments under the previous paradigm. Part of what made Einstein's theories so good is that they reinterpreted past theories while providing new explanations that fixed major unknowns in the science of the time. Both for GR and QFT.
- nimish 1y agoAm I missing something but the whole point of gauge theory (connections on a principal bundle) is that this is true, right? U(1) gauge theory gets you electromagnetism as a purely geometric result already?
- pdonis 1y agoYes, but the "geometry" in question is not the geometry of spacetime, it's the geometry of spacetime plus an abstract space that's sort of "attached" to spacetime. (In the original Kaluza-Klein viewpoint, it was viewed as an extra 5th spacetime dimension, basically a circle at every point of spacetime.) What this paper appears to be doing (although I can't make complete sense of it) is to somehow derive Maxwell's Equations (or more precisely a nonlinear generalization of them--which seems to me to mean that they aren't actually deriving electromagnetism, but let that go) as a property of the geometry of spacetime alone, without any abstract spaces or extra dimensions or anything of that sort.
- guerrilla 1y agoWhy would nonlinear generalizations be an issue? Wouldn't adding some constraints get us Maxwell's Equations? It seems significant that this can be done at all even if its not complete but maybe I'm missing something. It reminds me of Einstein's original geometrization, possibly even a breakthrough if it turns out to have uses in further development of theory.
- Iwan-Zotow 1y agoNonlinearity is not observed
- ajkjk 1y agoThe fact that it's some generalization of Maxwell makes it more fun, though---should means it's testable.
- leumassuehtam 1y agoYou're right that he is just rederiving electromagnetism through local U(1) gauge symmetry. He define his metric as g_{\mu\nu}=A_\mu A\nu, which is a gauge dependent metric that gives you Maxwell's equation in the covariant formulation when you identify the gauge field A_\mu with the vector potential. Sprinkling geometric algebra in gives a feel of novelty but these results is at least one hundred years old. *typo
- mkoubaa 1y agoThe most irritating kind of junior devs to work with are the ones who refactor code into abstraction oblivion that nobody can decipher in the name of code deduplication or some other contrived metric. That phenotype is well-represented in mathematical physics.
- im3w1l 1y agoI think sometimes you have to build the abstraction hell to completion and live with it for a while to truly realize it is in fact inferior. And even then, in science sometimes it never dies fully but lives on in some niche where it has desirable qualities.
- aeonik 1y agoIt's not my fault the universe is built on a hell of abstractions, I just model it. You ignore the reality of nature at your own peril. Besides, you can just use computers automate the wrangling of this hell. It's what they are good at, after all.
- bawolff 1y agoMathematicians and computer programmers use abstraction to opposite ends
- aleph_minus_one 1y ago> Mathematicians and computer programmers use abstraction to opposite ends I claim to be qualified in both disciplines. With this background, I disagree. If you are very certain what you want to model, abstractions are often very useful to shed light on "what really happens in the system" (both in mathematics and computer science, but also in physics). The problem with applying abstractions in computer programs (in this way) lies somewhere else: in business, users/customers are often very "volatile" what they want from the computer program, instead of pondering deeply about this question (even though this would be a very good idea). Thus (certain kinds of) abstractions in computer code make it much harder to adjust the program if new, very different requirements come up.
- mikhailfranco 1y agoReminds me of Feynman Checkerboard: https://en.wikipedia.org/wiki/Feynman_checkerboard https://en.wikipedia.org/wiki/Feynman_checkerboard and the work of David Hestenes: Zitterbewegung in Quantum Mechanics https://davidhestenes.net/geocalc/pdf/ZBWinQM15**.pdf https://davidhestenes.net/geocalc/pdf/ZBWinQM15**.pdf Zitterbewegung structure in electrons and photons https://arxiv.org/abs/1910.11085 https://arxiv.org/abs/1910.11085 Zitterbewegung Modeling https://davidhestenes.net/geocalc/pdf/ZBW_mod.pdf https://davidhestenes.net/geocalc/pdf/ZBW_mod.pdf
- hasley 1y agoRelated question: What resources are there that might teach one about Maxwell‘s equations and the electromagnetic field tensor arisig from relativity? The magnetic field is a description of the electric field with relativistic effects. Is there a way of describing electromagnetism without the magnetic field?
- bsder 1y agoI'm pretty sure this is what you want: "Collective Electrodynamics: Quantum Foundations of Electromagnetism" https://www.amazon.com/Collective-Electrodynamics-Quantum-Foundations-Electromagnetism/dp/0262632608 https://www.amazon.com/Collective-Electrodynamics-Quantum-Fo...
- hasley 1y agoThanks!
- inatreecrown2 1y agoAtom by Asimov?
- amelius 1y agoPurely geometric, except I suppose you still need Coulomb's law and relativity. Both of which can be easily put in a geometric framework. The rest is just how magnetism emerges from this, and Einstein already figured it out. This guy explains it pretty well in layman's terms: https://www.youtube.com/watch?v=sDlZ-aY9GN4 https://www.youtube.com/watch?v=sDlZ-aY9GN4
- oh_my_goodness 1y ago"charge density is a field, which propagates at the speed of light." Uh ...
- ajkjk 1y agoFrom a cursory reading I think they're referring to the idea that an electron traveling at v < c is a superposition of an electron traveling at c and a positron traveling at c. Which also is where the zitterbewegung comes from, because the two waves don't "cleanly" overlap, there's a bit of (not-yet-experimentally-verified) interference.
- Iwan-Zotow 1y agoBut this is non-linear EM
- amai 1y agoThese purely formal manipulations seem to skip over some important issues: If the equations of EM are the same as for gravity, then EM- charges should behave like mass. But like masses do attract each over, unlike EM-charges which do repel each other. I don't see how they resolve this basic difference between the behavior of masses and charges.
- mxmilkiib 1y agoreminds me of the end section of the "magnetic forces do no work" video by Angela Collier https://youtu.be/fHG7qVNvR7w?t=27m4s https://youtu.be/fHG7qVNvR7w?t=27m4s I love the entire rant/communication, but it ends with a classical view from a David Griffiths AIP interview, regarding a project by Jacob Barandes bit closer https://youtu.be/fHG7qVNvR7w?t=29m46s https://youtu.be/fHG7qVNvR7w?t=29m46s