A charge at rest would not emit EM waves but an accelerated charge would. But what is the observer is itself accelerated, will charge radiate EM waves as laws of physics should be same for all observers, right?
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This is a good question. It relates to what “observer at rest” means which never made sense to me – Al Brown Jul 26 '21 at 01:57
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When the observer is accelerating, the electric field produced by the charge becomes time-dependent, and due to Maxwell equations magnetic fields will be produced (therefore em wave will appear). I think that after some complicated calculation one can show that the Lorentz transformation of the original static electric field agrees with what the accelerating observer sees. – Zhengyuan Yue Jul 26 '21 at 02:48
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there are several articles about this, I never followed them fully, but they claim that an observer accelerating together with the charge will see no electromagnetic radiation, due to the "horizons" that SR predicts for accelerating observers. – Jul 26 '21 at 03:20
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Possible duplicate: https://physics.stackexchange.com/q/286457 – Nihar Karve Jul 26 '21 at 04:21
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But what is the observer is itself accelerated, will charge radiate EM waves as laws of physics should be same for all observers, right?
Wrong. The laws of physics are the same in all inertial frames. In other words for all inertial observers. By your assumption, the observer is accelerating. If the observer is accelerating under gravity, then according to General Relativity, they are an inertial observer. But any observer that is accelerating because of a thrust, (such as a rocket under thrust, a car accelerating because of its motor etc.) is NOT an inertial observer.
Does a charge radiate EM waves in non-inertial frame?
If a charge is not emitting an EM wave in any inertial frame, then it will not be emitting an EM wave according to an observer who happens to be non-inertial.
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