Where’s Richard Feynman when you need him?
A basic equation of electricity and magnetism is wrong, one scientist claims.
Where’s Richard Feynman when you need him?
A basic equation of electricity and magnetism is wrong, one scientist claims.
Quite frankly, commenting on this without being able to see what he’s proposing in detail would be silly. Add to that the fact that the article almost certainly deals exclusively in graduate to post-graduate physics material, and you might as well have posted an article synopsis in Linear Script B.
In short: Bleh! Nothing to see here, people. Move along.
I don’t see any indication that he’s taken the field momentum (and the angular momentum of the fields) into account in his “counterexample”. There’s a standard example in Griffiths (the usual upper-level undergraduate book on this material; it’s at the end of Chapter 10, I think) in which the force between a moving charge and a stationary charge are not equal and opposite. This means that the linear momentum of the charges is not conserved, and therefore that there’s a net force between the charges. The resolution is that the net change in the momentum of the charges is balanced by a change in linear momentum of the electromagnetic fields. If you went to a different frame, in which the charges are moving towards each other with equal and opposite velocity, you’d find that the forces are equal and opposite, and so no net force on the charges would be needed in this frame.
The analogue here would be that if there’s some angular momentum in the system he proposes (which seems plausible) and this angular momentum is changing with time (which it probably would be, since the charges are moving in the frame where the contradiction occurs), then of course there would have to be a net torque between the charge and the dipole in this frame. In another frame moving with the charge & dipole, the angular momentum would be constant with respect to time, and so no net torque would be present.
It took me about 15 minutes worth of thought to come up with this object, BTW, so it may be incorrect. Still, I’d be willing to bet $10 that there’s an angular momentum present in the fields in one of the frames that the author didn’t account for, and that when accounted for, would resolve this “paradox”.
In the first paragraph of section 2, the author writes
The Lorentz law is for force, not for torque, so I don’t understand how this torque demonstrates that the force law is wrong. Am I missing something?
Electromagnetism (including the Lorentz force) is in fact what inspired Einstein to develop Special Relativity to begin with. It’s not consistent with anything but SR.
I don’t see how the argument can even get off the ground – the Lorentz force law can be expressed in a manifestly covariant way, which basically means that it transforms the way quantities in special relativity ought to transform if you go to a different reference frame, so there’s not really any room for disagreement with SR…