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Author Topic: Does a particle moving near C emit radiation?  (Read 1801 times)

Offline Ron Hughes

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Does a particle moving near C emit radiation?
« on: 24/03/2010 13:09:49 »
I've looked online but have been unable to find the answer.


 

Offline graham.d

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Does a particle moving near C emit radiation?
« Reply #1 on: 24/03/2010 14:00:59 »
We covered this a lot in the discussion:

http://www.thenakedscientists.com/forum/index.php?topic=28617.0

a topic also started by you, Ron.

It seems it is a subject that is quite deep and not wholly understood. I did a fair bit of research (well, as much as time allowed) and noted that there was quite a bit of disagreement amongst physicists on the subject.
 

Offline Ron Hughes

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Does a particle moving near C emit radiation?
« Reply #2 on: 24/03/2010 15:59:13 »
I am not referring to an accelerated particle. I'm talking about a charged particle traveling near C with respect to an observer.
 

Offline Soul Surfer

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Does a particle moving near C emit radiation?
« Reply #3 on: 24/03/2010 18:17:48 »
In truly empty space no, a particle does not lose any energy by emitting radiation however, in our universe the cosmic microwave background represents a potential source of interactions and energy loss if the particle has a high enough energy.  This sets a predicted upper limit on the energy of cosmic rays that could travel a long distance across the universe because they would lose energy in their interactions with CMB photons.  This limiting energy is way above the highest energies that are ever likely to be achieved by man made accelerators.

 

Offline Ron Hughes

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Does a particle moving near C emit radiation?
« Reply #4 on: 25/03/2010 01:37:14 »
Since there is no place in the Universe where radiation does not exist then charged particles in motion with respect to an observer probably do lose some energy as very long wavelength radiation. As you already know, a charged particle will emit radiation wither it loses or gains energy with respect to an observer.
 

Offline graham.d

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Does a particle moving near C emit radiation?
« Reply #5 on: 25/03/2010 12:37:54 »
Sorry Ron. I opened your post but then forgot the heading which was your question.

A note to the web designers: it would be useful to still show the topic header after you open the topic.

To reply to your question, I agree that without interactions with em fields, or other fields, there would be no radiation - at least I can't think of a mechanism.
 

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Does a particle moving near C emit radiation?
« Reply #5 on: 25/03/2010 12:37:54 »

 

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