Examining EM Radiation and Charge: The Truth About Emission and Movement

[spidey]

Does a stationary charge emits electromagnetic radiation?
Does a moving charge in magnetic field emits electromagnetic radiation?

 

[Meir Achuz]

A stationary charge would only emit radiation if it were acceleratiing, and then it would no longer remain stationary.
A moving charge in a magentic field would accelerate and thus emit EM radiation
(unless it were moving at constant velocity parallel to the B field.)

 

[confuted]

A stationary charge would only emit radiation if it were acceleratiing, and then it would no longer remain stationary.

There is considerable debate over whether a uniformly accelerating charge does, in fact, radiate. http://www.mathpages.com/home/kmath528/kmath528.htm" .

 

[Meir Achuz]

I don't know the author or status of that shoddy website, but every textbook I have seen
(about 20) states that a uniformly accelerating charge does, in fact, radiate.
Perhaps "considerable" is a confuted overstatement.

 

[confuted]

As I stated, that site should have been nothing but a starting point. You want peer reviewed papers? You've got 'em.

Annals of Physics, 124, 169-188 (1980)
http://www.hep.princeton.edu/~mcdonald/examples/EM/boulware_ap_124_169_80.pdf

The question of whether a uniformly accelerated charge radiates has been the
subject of a long series of papers with some distinguished authors reaching the
conclusion that it does while others, equally distinguished, reach the conclusion
that it does not.

http://www.springerlink.com/content/v42441306604p571/
http://arxiv.org/pdf/gr-qc/9805097

The emission of radiation from a uniformly accelerated charge is considered to be a well solved problem. However, when the solution of this problem is treated in its relevance to the principle of equivalence, and to observations made by observers located in different frames of reference, some contradictions appear to exist in the solution.

Phys. Rev. 76, 543 - 544 (1949)
http://prola.aps.org/abstract/PR/v76/i4/p543_1

It has been stated that there is no radiation from a charge moving in the relativistic equivalent of uniform acceleration. This proves to be not the case when means of measuring the radiation are used which are suitable to the infinite extent of the path.

http://www.springerlink.com/content/75rf4n6h51xgurcj/
http://arxiv.org/pdf/gr-qc/9303025

It is generally accepted that any accelerated charge in Minkowski space radiates
energy. It is also accepted that a stationary charge in a static gravitational
field (such as a Schwarzschild field) does not radiate energy. It would seem that
these two facts imply that some forms of Einstein’s Equivalence Principle do
not apply to charged particles.

http://www.springerlink.com/content/g737h237t0675327/

The electromagnetic field of a charge supported in a uniform gravitational field is examined from the viewpoint of an observer falling freely in the gravitational field. It is argued that such a charge, which from the principle of equivalence is moving with a uniform acceleration with respect to the (inertial) observer, could not be undergoing radiation losses at a rate implied by Larmor's formula. It is explicitly shown that the total energy in electromagnetic fields, including both velocity and acceleration fields, of a uniformly accelerated charge, at any given instant of the inertial observer's time, is just equal to the self-energy of a non-accelerated charge moving with a velocity equal to the instantaneous ldquopresentrdquo velocity of the accelerated charge. At any given instant of time, and as seen with respect to the ldquopresentrdquo position of the uniformly accelerated charge, although during the acceleration phase there is a radially outward component of the Poynting vector, there is throughout a radially inward Poynting flux component during the deceleration phase, and a null Poynting vector at the instant of the turn around. From Poynting's theorem, defined for any region of space strictly in terms of fixed instants of time, it is shown that a uniformly accelerated charge does not emit electromagnetic radiation, in contrast to what is generally believed.

I'll admit to not having read these articles, but the abstracts alone should be sufficient to convey my point; there is some debate.

Indeed, my Google searches even brought me to this thread:
https://www.physicsforums.com/showthread.php?p=1921540

It seems you've been confuted. I suggest finding the word in a dictionary before you use it again.

 

[atyy]

https://www.physicsforums.com/showthread.php?t=263434