Yet another radiation question

[anonymous299792458]

If the acceleration of the charge is constant, it radiates. However, the radiation reaction force, which depends only on the third and higher derivatives of x with respect to t, is 0. How is this explained? Didn't Feynman say that, in fact, in the case of constand acceleration, there's NO radiation? I have also read that it is an experimental fact that an accelerated charge radiates, even if the acceleration is constant. This question has been really bugging me for many months. I still haven't been able to find the answer. SO WHAT'S THE DEAL HERE??

 

[Vern]

I think you will find that a charged object undergoing constant acceleration will emit electromagnetic radiation. I don't remember Feynman saying otherwise ) Which wouldn't matter anyway.

 

[Graeme Robinson]

The issue of radiation from an accelerated charge is a complex and ongoing topic in physics. While it is true that according to classical electrodynamics, a charge that undergoes constant acceleration does not radiate, this is not the full picture. In reality, the situation is more nuanced and involves the interplay of various factors such as the nature of the charge, the medium it is moving through, and the specific conditions of the acceleration.

Firstly, it is important to note that the concept of radiation reaction force, which is often used to explain why an accelerated charge should radiate, is a theoretical construct and does not necessarily have a direct physical manifestation. As such, its value of 0 in the case of constant acceleration does not necessarily mean that there is no radiation.

Furthermore, while Feynman did state that there is no radiation in the case of constant acceleration, this was in the context of a single point charge moving in a vacuum. In reality, most charges are not point charges and are surrounded by a cloud of other particles, which can lead to radiation even in the case of constant acceleration.

Additionally, experimental evidence has shown that an accelerated charge does indeed radiate, even if the acceleration is constant. This can be explained by taking into account the effects of quantum mechanics, which can lead to radiation even in the absence of classical radiation reaction forces.

In summary, the issue of radiation from an accelerated charge is a complex one, and while classical electrodynamics may suggest that there is no radiation in the case of constant acceleration, other factors such as quantum effects and the nature of the charge can lead to radiation in practice. It is an ongoing area of research and there is still much to be understood about this phenomenon.