Why do accelerated charges emit e/m radiation?

In summary, the conversation discusses a question about why an accelerated charged particle loses energy via e/m radiation. The use of Bohr's model of the atom is explained to be incorrect as it causes electrons to spiral towards the center. The Purcell text offers a good explanation based in relativity, which is also mentioned on a website provided. The main concept discussed is that electromagnetic disturbances propagate at the speed of light, creating a wavefront that carries information about the acceleration of the charge.
  • #1
sor2char
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Hi first time post here and the site is awesome.
Question is in the title really. I am a second year physicist at UMIST, manchester, England and worry about why an accelerated charged particle loses energy via e/m radiation. For example Bohr's model of the atom consisting of electrons physically orbitting the nucleus was proved incorrect as the elctrons would spiral towards the centre.
 
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  • #2
the purcell text i used this year had a very good explanation based in relativity, somewhat replicated at this site: www.chem.yale.edu/~cas/jenkins.html[/URL]

basically, electromagnetic disturbances propagate at the speed of light. so the information that the charge (and the field from the charge) has acclerated reaches a certain point away from the charge at a later time, indicated by the picture to the right. this creates a sort of wavefront.
 
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  • #3


Accelerated charges emit e/m radiation because of their changing electric and magnetic fields. As the charge accelerates, its electric field changes, creating a magnetic field. These two fields oscillate and propagate away from the charge as electromagnetic waves. This process is known as radiation.

The amount of energy emitted by a charge depends on the acceleration and the strength of the charge. This is why in Bohr's model, the electrons would eventually spiral towards the nucleus - their acceleration would increase as they got closer to the nucleus, resulting in a stronger emission of e/m radiation and loss of energy.

This phenomenon is also observed in other systems, such as synchrotrons and particle accelerators, where charged particles are accelerated to high speeds and emit e/m radiation in the form of x-rays or gamma rays.

In addition, the conservation of energy and momentum also plays a role in the emission of e/m radiation. As the charged particle loses energy through radiation, it also experiences a recoil force in the opposite direction, causing it to slow down and change direction.

In conclusion, accelerated charges emit e/m radiation due to the changing electric and magnetic fields, and this process leads to the loss of energy and change in direction of the charged particle. This is a fundamental concept in electromagnetism and has many practical applications in various fields of physics.
 

1. Why do accelerated charges emit e/m radiation?

Accelerated charges emit e/m radiation because they experience a change in their electric and magnetic fields as they accelerate. This change in the fields creates electromagnetic waves that propagate outward from the charge.

2. What is e/m radiation?

E/m radiation, also known as electromagnetic radiation, is a form of energy that is carried by electromagnetic waves. These waves consist of oscillating electric and magnetic fields and can travel through space at the speed of light.

3. How is e/m radiation related to the acceleration of charges?

E/m radiation is directly related to the acceleration of charges. As charges accelerate, their electric and magnetic fields change, which creates electromagnetic waves. The stronger the acceleration, the more intense the e/m radiation will be.

4. What are some common examples of accelerated charges emitting e/m radiation?

Some common examples of accelerated charges emitting e/m radiation include radio waves from an antenna, visible light from an incandescent light bulb, and X-rays from a medical imaging machine. In all of these cases, the charges (electrons) are accelerated in some way, causing them to emit electromagnetic waves.

5. Is e/m radiation harmful?

The answer to this question depends on the intensity and type of e/m radiation. Some forms of e/m radiation, such as X-rays and gamma rays, can be harmful to living organisms at high levels of exposure. However, other forms, like visible light and radio waves, are generally not harmful. It is important to limit exposure to high levels of e/m radiation, particularly ionizing radiation, to protect against potential health risks.

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