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bhobba

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Anyone know the answer or is it tied up with weird stuff like runaway solutions to the Lorentz-Dirac equation that really requires QED.

Thanks

Bill

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- Thread starter bhobba
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bhobba

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Anyone know the answer or is it tied up with weird stuff like runaway solutions to the Lorentz-Dirac equation that really requires QED.

Thanks

Bill

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Vanadium 50

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- #3

bhobba

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Radiation involves multipoles, which are extended objects.

Got it.. If you have say a charge sitting on a table and you go to a freely falling local frame so the charge accelerates upwards the field outside this local frame still resides in a gravitational field. Its not inertial and Maxwell's equations don't strictly apply - you need GR.

Thanks

Bill

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I am not sure if I got the question and your conclusion right...

If you regard for example a single accelerated particle you can first get to the Larmor formula (non-relativistic). Elementary particles can accellerate hellacious, so you can formulate this in a SRT way. See J.D. Jackson, chapter 14 - which is needed in particle accelerators.

GRT is not needed here in any way. Naturally you can write the Maxwell equations in a GRT way which look the same as the SRT ones if you use the coordinate free language (differential forms). Nevertheless, the standard radiation you observe has nothing to do with this.

The GRT part would be interesting if you watch as a free falling observer a charged particle itself free falling in your reference frame. Is this case you would measure the acceleration relative to your position - which is an higher order effect depending purely from the curvature - which is normally very very small.

Best regards,

Jens

- #5

tech99

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I wonder if the animation at the following URL will be helpful: http://www.tapir.caltech.edu/~teviet/Waves/empulse.html

Anyone know the answer or is it tied up with weird stuff like runaway solutions to the Lorentz-Dirac equation that really requires QED.

Thanks

Bill

It is based on the radiation mechanism proposed by J J Thompson.

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