Classical electromagnetic theory

AI Thread Summary
Classical electromagnetic theory posits that a particle must change both its direction and speed to be considered accelerating, which contradicts the behavior of particles in uniform circular motion. Maxwell's assertion that accelerating particles radiate energy raises questions about the accuracy of classical theory, particularly in relation to the Rutherford model. Some argue that a change in direction alone constitutes acceleration, while others insist that speed must also change for true acceleration. The discussion also touches on Bohr's model, which suggests that particles can transition between energy levels without radiating energy, challenging classical interpretations. Overall, the conversation highlights confusion and debate over the definitions and implications of acceleration in classical electrodynamics.
Vaibhav Dixit 1008
According to classical electromagnetic theory,for acceleration a particle must not only change its direction but it should also increase its speed. But Maxwell said that a particle accelerates then it radiates energy.(this is with reference to Rutherford model). But actually the particle is not accelerating because it is changing its direction not speed. So is classical theory wrong or Maxwell didn't get classical theory or Rutherford a genious..??
 
Physics news on Phys.org
Vaibhav Dixit 1008 said:
But actually the particle is not accelerating because it is changing its direction not speed.
A change in direction is an acceleration too.
 
But according to classical electrodynamics
If a particle is to accelerate then it should not only change its direction but speed must also change.
 
Vaibhav Dixit 1008 said:
but speed must also change.

No. You can have acceleration and constant speed at the same time.
 
I know that we can have acceleration and constant speed at same time.
But according to classical electrodynamics a particle must also change its speed in order to accelerate during uniform circular motion.
 
Vaibhav Dixit 1008 said:
But according to classical electrodynamics a particle must also change its speed in order to accelerate during uniform circular motion.
Then how is that circular motion uniform?
 
  • Like
Likes russ_watters
Vaibhav Dixit 1008 said:
But according to classical electrodynamics
If a particle is to accelerate then it should not only change its direction but speed must also change.
Can you cite your source for this? I think you may just be misunderstanding some other point that is being made
 
Vaibhav Dixit 1008 said:
According to classical electromagnetic theory,for acceleration a particle must not only change its direction but it should also increase its speed. But Maxwell said that a particle accelerates then it radiates energy.(this is with reference to Rutherford model). But actually the particle is not accelerating because it is changing its direction not speed. So is classical theory wrong or Maxwell didn't get classical theory or Rutherford a genious..??
Did Maxwell actually say that? I thought it was JJ Thompson and JJ Larmor a few years later.
 
Not helpful.
 
  • #10
Let me make it more theoretical
When we talk about limitations of Rutherford model, Maxwell quoted that an accelerating charged particle radiates energy and its energy continuously decreases and it comes to rest. But this term acceleration doesn't fit here.
According to law of classical electrodynamics if a charged particle is to accelerate then it must increase its speed. There is a clause here that the speed of particle should neither be constant nor be decreasing. It should increase. So I think Maxwell said wrong thing.
 
  • #11
Now I come to another point. Bohr was really clever. He said that particle doesn't radiate energy. How can that be possible??
See what Bohr actually did. He did a clever usse of law of electrodynamics. According to Bohr a particle can move from low energy level to high energy level. In doing so it doesn't radiate energy because magnitude of velocity decreases which is in coordination with law. Now after 10 raised to power -8 seconds it returns back. Now speed of particle increases. It radiates energy. That's what I want to say.
Now tell Maxwell was not a good student.
 
  • #12
Vaibhav Dixit 1008 said:
According to law of classical electrodynamics if a charged particle is to accelerate then it must increase its speed.

We keep telling you this is wrong and you keep saying this. Why is that?
 
  • #13
Vaibhav Dixit 1008 said:
That's what I want to say.
Now tell Maxwell was not a good student.

You mixed so many different things... Bohr model has nothing to do with your question, because it's not classical. And you seem to ignore what people write to you...
 
  • #14
Vaibhav Dixit 1008 said:
if a charged particle is to accelerate then it must increase its speed.
Vaibhav Dixit 1008 said:
He said that particle doesn't radiate energy
Please send me a PM with your sources for these.
 
Back
Top