Has any Prominent Physicist Ever Admitted to Not Understanding Magnetism?

Discussion in 'Physics & Math' started by Eugene Shubert, Sep 17, 2015.

  1. James R Just this guy, you know? Staff Member

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    What is gibberish to you probably makes a lot more sense to somebody who has had a year or two of education in physics.

    Maxwell's equations specifically relate the electromagetic field to the electrical charges that cause those fields. The origin of electromagetic forces is ultimately electrical charges.

    A curved spacetime is a bit like a field - just a four-dimensional one.

    It wouldn't make sense to explain electromagnetism in terms of spacetime curvature because the acceleration of a charge is not independent of its mass.
     
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  3. danshawen Valued Senior Member

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    Can Eugene or anyone here explain WHY a stone, if dropped, accelerates downward to the exact geometric center of the planet, instead of, say, something like the center of mass of the SME (Sun Moon Earth) system? This would be a point nearer the core of the Sun, wouldn't it? Even Newton's law of gravitation assumes masses that are at rest with respect to each other in the first approximation. If the SME system were a static one, the Earth along with the stone would abruptly fall in that direction together. Imagine trying to explain this to someone who lived before Newton lived.

    The stone shares the motion/acceleration of the Earth itself, which is already orbiting the Sun. The stone starts falling from nearer the surface of Earth rather than the moon. If it could fall completely through the Earth without encountering any resistance from the intervening mass, where would it end up, at Earth's geometric center, or at some point or set of points orbiting the Earth's core once each month due to the influence of the center of mass of the Earth- Moon system? Even differences in masscons within the Earth would affect this motion.

    See how difficult questions are to answer or quickly become if you always start them with the interrogative: 'Why?'
     
    Last edited: Sep 18, 2015
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  5. origin In a democracy you deserve the leaders you elect. Valued Senior Member

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    Well the obvious reason that it does not accelerate towards the center of the sun is because we are in orbit (free fall) around the sun.
     
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  7. danshawen Valued Senior Member

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    And what, exactly, is the origin of electric charge? My, that certainly did escalate quickly into something less answerable at a level a layman could understand. I do understand that the force carrier in EM is the photon. Doesn't seem like a photon would be able to exert enough pressure to repel a magnet, does it? You'd pretty much be able to see (or else FEEL) that many photons transferring a force, wouldn't you? Where is the WHY G-d of the Standard Model now?

    Are the photons altered by relativity so that we can't see any of them without iron filings? Are they acting through a quantum field as an intermediary? What? Why? Is the field still there when no other magnets or coils of wire are around?
     
    Last edited: Sep 18, 2015
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  8. Little Bang Registered Member

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    Electric charge, the photon and time dilation, if we could explain these it probably would answer all the other questions we have about the Universe
     
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  9. rpenner Fully Wired Registered Senior Member

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    The phenomena related to time dilation arise in our most accurate and parsimonious models of the behavior of reality because that which we call time and that which we call space are aspects of just one thing, called space-time, and that one thing exhibits properties that can vary from place-to-place called curvature that differentiates it from "flat" Minkowski space-time. The OP accepts this as an answer.

    The phenomena related to electric charge arise in our most accurate and parsimonious models of the behavior of reality because that which we call the electron quantum field (among others) and that which we call the photon quantum field are aspects of just one thing, and the description of the relation between the two is a non-zero scalar coupling constant that differentiates it from a hypothetical universe with neutral electrons (among others). The OP does not accept this as an answer despite the same methodology as the above.
     
  10. Little Bang Registered Member

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    And therefore my statement was totally useless to you and for that I humbly beg your pardon but there may be others with whom it does resonate. Saying that the explanation of an apple is the tree from which it was produced does not explain the apple.
     
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  11. rpenner Fully Wired Registered Senior Member

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    If it doesn't, then perhaps your definition of "explain" has no bearing on the observable behavior of phenomena of reality and instead rests in some metaphysical philosophy.

    But the apple you are thinking of has its origins in the action of man domesticating the asian wild apples and selectively breeding them to cultivate traits judged by man to be good. The wild apples were themselves selected for millions of years by mammals which lead them to develop larger and juicer fruits than the berry-sized fruits of their ancestors.

    http://www.botany.wisc.edu/courses/botany_940/06CropEvol/papers/Harris&02.pdf
     
  12. spidergoat Valued Senior Member

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    Gravity is dependent on distance. So only the Earth has a big effect on objects near the Earth.
     
  13. rpenner Fully Wired Registered Senior Member

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    Gravity has unlimited range, so every object on Earth and the Moon is already falling about the Sun as much as they already can be. An elliptical orbit is what you get when you fall under gravity but have enough sideways motion to miss a collision and not enough kinetic energy to escape to arbitrarily large distances.

    Because the Earth has finite radius, it has points closer to and further away from the Sun and those points experience slightly different pulls from the Sun. Likewise the moon, but to a larger extent since the Moon, while much less massive is much closer. Those two differential pulls create tidal bulges which slosh the oceans around creating a specific pattern of local tides with strong periodicities which reflect the response to the oceans sloshing about irregularly shaped bays and seafloors.

    Differential acceleration measurements of nearby masses of different elemental composition confirm that our free fall about the sun is universally observed to within a few parts per ten trillion, confirming a Galilean hypothesis to high precision.
     
    Last edited: Sep 18, 2015
  14. Boris2 Valued Senior Member

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    why are posts like this allowed to persist? move it to pseudoscience.
     
  15. rpenner Fully Wired Registered Senior Member

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    Unclear antecedent.

    If you mean the original post (OP), by Eugene Shubert, a less drastic option would be to re-title the thread to remove his anti-science bias. I proposed that in post #3. A less labor intensive option would be to ban the user for life and add a CSS rule that would append a small warning image of a steaming pile of dog excrement to any links to his self-published content. The latter option diverges from the appearance of civility that the staff wish to maintain.
     
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  16. brucep Valued Senior Member

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    He's a complete illiterate when asking these stupid questions. In the metric electric charge is a component of the mass. As is angular momentum. The theory of general relativity predicts everything electromagnetic contributes to the local spacetime curvature. Why Shubert would demand that a single component would be required to explain the whole is why he's an illiterate crank.
     
  17. James R Just this guy, you know? Staff Member

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    Huh? Could you please explain?
     
  18. brucep Valued Senior Member

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    Look at the Kerr metric in this project. The angular momentum [rotation parameter a] sums to the mass. It's the same for electric charge.
    http://www.eftaylor.com/download.html#general_relativity
    This the wiki for the Kerr-Newman metric which shows the charge per unit mass. ...... per unit mass. The angular momentum is expressed as per unit mass and so is electric charge. The old black hole has no hair theorem. The only thing we can measure is the mass, angular momentum, and electric charge.
    Pick Project 9 at the Taylor site. To help with familiariazation when the black hole is extremal the rotation parameter a=M and r=M. Makes some of the math pretty easy to look at.
     
    Last edited: Sep 21, 2015
  19. rpenner Fully Wired Registered Senior Member

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    I think the reason you can the Kerr-Newman metric has a charge is that the electromagnetic fields turns the vacuum into an electrovacuum. In other words, Maxwellian fields carry energy and momentum, therefore are sources of gravity even in otherwise "empty" space.
    In the Kaluza theory, the ignorance of which I alluded to in post #28, my snarky paraphrase of post #11 and others, I linked to a recent article contradicting the assertion:
    Basically, Kaluza theory replaces the 4×4 symmetrical metric of spacetime (with \(\frac{4 \times ( 4 +1 )}{2} = 10\) independent components) with a 5×5 metric ( (with \(\frac{5 \times ( 5 +1 )}{2} = 15\) independent components) where the new components correspond to the Maxwellian vector potential and a new scalar field. There is an assumption called the cylinder condition that the fields don't depend on the new direction.

    Then you get the Maxwellian energy tensor for free. (Meaning no additional assumptions, but a lot of mathematical heavy lifting from the assumptions.)

    There is also a related Wikipedia page where it is shown that the Lorentz force law implies the velocity of matter in the new direction is proportional to the charge-mass ratio. One new dimension, two new directions = two equal and opposite types of charge.
     
    Last edited: Sep 21, 2015
  20. brucep Valued Senior Member

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    Forgot to link the Kerr-Newman
    https://en.m.wikipedia.org/wiki/Kerr–Newman_metric
     
  21. Little Bang Registered Member

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    I must admit the above explanations for charge are way outside the abilities of my feeble intellect.
     
  22. Little Bang Registered Member

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    It would be so nice if we would face the fact that we have no clue as to the cause of charge.
     
  23. Yazata Valued Senior Member

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    In my opinion, one of the real defects of Sciforums is its participants unwillingness/inability to teach.

    If people think that they have a superior knowledge of the subject, then they should be willing to teach those who don't. In other words, if a year or two of university physics provides one with a credible explanation for action-at-a-distance, then those who understand the explanation should be willing to help explain it to those who don't. (I took the first year physics introductory sequence as a biology major back in the 1970's, and don't recall being taught the explanation then. Maybe it's a second-year thing...)

    'Teaching' does not mean loud and angry assertions of authority or showing off with graduate-level jargon that probably only the writer understands. It means helping the student understand, to see the how, why and logic of things for his/her self.

    I still remember somebody starting a thread about a year ago saying that when he looked at Schroedinger's equation he saw a bunch of little backwards 6's'. He asked what the little backwards 6's were and what they meant. The response to his question was some kind of advanced mathematical dissertation on Schroedinger's equation, that anyone with an ounce of sense should realize would go totally over the head of somebody who didn't recognize partial derivatives. I believe that I was the only one in that thread that tried to explain what partial derivatives are and what motivates their use in physics. (And my knowledge of physics and math is limited at best.)

    It's sad, Sciforums could be much more helpful and educational than it is. What the board needs is fewer people boasting about their advanced degrees from the world's most prestigious universities, and a few more high-school teacher types able and willing to teach beginners so that the beginners can actually understand.

    So how does an electric charge at point A exert a force on another charge some distance away at point B? Saying that charges are associated with fields that are defined by the magnitude of the forces that charges feel at various points still doesn't explain the mechanism. Dismissing inquiries into the mechanism as "metaphysics" doesn't bring us any closer to answering the question.

    That dismissive move can be used to dismiss all of science. Why can birds fly and what principles make bird wings work? They fly because it's the nature of birds to fly, because flight is part of a bird's essence. How do animals move? They move because life-force animates them and life-force is essentially an animating principle. Any further inquiry into the mechanisms is merely inappropriate metaphysics, inquiries into why God created things as he did. That's how many medievals saw things.

    The history of science suggests that science has advanced precisely when it's asked the questions that it wasn't supposed to ask. So why shouldn't the same kind of questions be asked about fields? It seems to me that there are still some outstanding mysteries there.

    If we are supposed to think that general relativity and its ideas about spacetime curvature are an advance on thinking of gravitational fields as givens, as essences not subject to further explanation, then why shouldn't we suspect that other fields might still be awaiting similar advances?
     
    Last edited: Sep 21, 2015
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