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jason12345
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Is there a consensus on whether or not a co-accelerated observer measures radiation from an accelerated charge?
clem said:I think it is clear that such radiation is measured.
vin300 said:See this threadhttps://www.physicsforums.com/showthread.php?t=324201&page=2"
See the link.
Vanadium 50 said:A charge resting on the surface of the Earth does not accelerate.
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Vanadium 50 said:The short answer is "yes, there is radiation". If you hold up a radiation measuring device, it indicates radiation.
One can then quibble endlessly about this. The longer answer is that locally, you can't tell if you have radiation or just near-field electric and magnetic fields. You can have electric and magnetic fields acting as if they are radiation, but until you measure the 1/r fall off, you can't tell radiation from near-field. So you need an extended object to do the measurement, and this extended object doesn't form a unique reference frame. So the question is actually ill-defined: one strictly speaking cannot build a radiation detector that is in a comoving frame with a point charge.
Let me reiterate the short answer, because it's more important than the quibbling: "yes, there is radiation". If you hold up a radiation measuring device, it indicates radiation.
jason12345 said:But a measuring device co accelerating with the charge in the far field won't detect radiation, right?
That's wrong. The equivalence principle does apply to electrically charged particles. The effect on a charged particle accelerating under Earth's gravity(and note, a change in acc can only produce radiation) is the same as in a frame with corresponding opposite acc, look at the first two equations in the link provided in this threadhttp://www.mathpages.com/HOME/kmath528/kmath528.htm"atyy said:The equivalence principle does not apply to electrically charged particles. A charged particle cannot fall freely (ie. under the influence of gravity alone), because as it accelerates in the gravitational field it will give off electromagnetic radiation, which will act on the charge itself - so the charge is no longer falling under the influence of gravity alone.
Vanadium 50 said:I'm arguing that there is no such thing as "a measuring device co accelerating". This device has to be an extended object, and relativity of simultaneity means its not in a single frame at all, much less the same frame as the source.
jason12345 said:OK, so let's minimise the effects of relativity of simultaneity by using an infinitesimally small measuring device and velocity.
Vanadium 50 said:So you need an extended object to do the measurement
What's your problem?jason12345 said:OK, so let's minimise the effects of relativity of simultaneity by using an infinitesimally small measuring device and velocity.
A co-accelerated charge refers to two or more charges that are moving together at the same acceleration.
No, not all co-accelerated charges will radiate. It depends on their relative acceleration and the nature of their movement.
The two main factors that determine if a co-accelerated charge will radiate are the magnitude of the acceleration and the direction of the motion of the charges.
Radiation is produced by a co-accelerated charge when there is a change in the electric and magnetic fields surrounding the charges. This change is caused by the acceleration of the charges and results in the emission of electromagnetic waves.
The study of co-accelerated charge radiation has various applications in fields such as electromagnetism, telecommunications, and particle physics. It also helps us understand the behavior of electromagnetic waves and their interactions with matter.