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Physics, Astronomy & Cosmology / Re: Can Planck's law curve be matched to Rayleigh-Jean's law curve like this?
« on: 22/01/2024 18:43:59 »
Hi.
LaTex still isn't working on the forum. However, there's a good derivation for the e-m radiation that must arise in the far field due to an oscillating electric dipole here: It's 24 minutes long and maybe nicer than working through the mathematics entirely on your own. Sadly, I don't think this You Tuber went further and made a video for section 9.5 of Griffith's which should be an oscillating magnetic dipole - but it's a reasonable template of how you would try and do the maths. It's completely un-necessary to watch the video but there's at least two people in the world who might care about the maths.
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I think quite a few of us (maybe 3 people and that's about half the forum) recognise that a rotating magnet must emit e-m radiation.
Best Wishes.
..one has to remember that the magnetic field is simply the electric field as seen from a different frame of reference...Well said, I very nearly added that to the list of things @alancalverd has probably said to other people.
I never could do the maths, but I don't care.You've made a good argument without the Mathematics.
LaTex still isn't working on the forum. However, there's a good derivation for the e-m radiation that must arise in the far field due to an oscillating electric dipole here: It's 24 minutes long and maybe nicer than working through the mathematics entirely on your own. Sadly, I don't think this You Tuber went further and made a video for section 9.5 of Griffith's which should be an oscillating magnetic dipole - but it's a reasonable template of how you would try and do the maths. It's completely un-necessary to watch the video but there's at least two people in the world who might care about the maths.
I have looked up the derivation of the wave equation via the Laplacian of the E or H field in phasor form and it is completely symmetric: a time variation in either produces an em wave.Thank you.
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I think quite a few of us (maybe 3 people and that's about half the forum) recognise that a rotating magnet must emit e-m radiation.
If the magnet falls over in a non-existent forest with no observers, does it matter?Hmm... I've often wondered, if I'm alone in the woods and my wife and daughters cannot hear me, am I still wrong?
A monopole would throw a spanner in the maths where divH is required to be =0.You've already given the smart answer. Maxwells equations will not permit a magnetic monopole, so we can't use them and expect to get a sensible answer. As far as I know, quantum theories that do predict magnetic monopoles will have them behave much like an electric charge.
Best Wishes.
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