Electromagnetic field vs electromagnetic wave "radiation"

  • #1
user079622
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( @jrmichler wrote to me: "SHEESH, more fearmongering. But please do not bring these conspiracy theories to PF."

You write to wrong person, you and moderator of PF can send a email to scientists in WHO/International Agency for Research on Cancer (IARC) and ask them why they make this conclusion. I just make copy of their text, I am not biologist or doctor and I am not interested in this discussion.

Quote from International Agency for Research on Cancer (IARC):
Conclusion:
"Lyon, France, May 31, 2011 ‐‐ The WHO/International Agency for Research on Cancer (IARC) hasclassified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B).."

" Overall, extremely low frequency magnetic fields were evaluated as possibly carcinogenic to humans (Group 2B).."



sources:
https://www.iarc.who.int/wp-content/uploads/2018/07/pr208_E.pdf
https://publications.iarc.fr/98
)

Back to my topic Electromagnetic field vs electromagnetic wave "radiation" , please don't go off topic again, I am interested in physics not medicine.

@Baluncore

Does AC current in one wire produce EM wave or fluctuating EM field around it, does emf separated from source(wire) and propagate to space, so can we even call this "radiation" and consider this wire as " transmitter"?
 
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  • #2
user079622 said:
" Overall, extremely low frequency magnetic fields were evaluated as possibly carcinogenic to humans (Group 2B).."
Does AC current in one wire produce EM wave or fluctuating EM field around it, does emf separated from source(wire) and propagate to space, so can we even call this "radiation" and consider this wire as " transmitter"?
@user079622 have you even read your second cited reference https://publications.iarc.fr/98?
From page 37 of that report:
"At frequencies above those of interest here, electromagnetic fields propagate by means of tightly coupled electric and magnetic fields (radiation). In such cases, the magnitude of the electric field can be calculated exactly if the magnetic field is known and vice versa. However, in the ELF range, electric and magnetic fields are effectively uncoupled and can be evaluated separately as if they arose from independent sources. At the low frequencies where it is customary to use the quasi-static approximation, the wavelengths of electric and magnetic fields are very large (approximately 5000 km at 60 Hz1) in relation to the size and distances of objects of interest (National Radiological Protection Board, 2001). Under these ‘near-field’ conditions (less than one wavelength), electric and magnetic fields do not effectively ‘radiate’ away from the source nor do they occur together in an interrelated way. The field produced by a source is better described as a zone of influence in which the forces on electrical charges oscillate in time and space. More detailed information on physical characteristics may be found elsewhere (e.g. Polk & Postow, 1995)."
So the answer to your question is no.
 
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  • #3
renormalize said:
So the answer to your question is no.

So these accepted answers are wrong?

https://physics.stackexchange.com/questions/93507/does-ac-current-produce-em-waves
https://physics.stackexchange.com/questions/416409/do-the-wires-having-ac-current-emit-em-waves

"However, in the ELF range, electric and magnetic fields are effectively uncoupled and can be evaluated separately as if they arose from independent sources"

Why in ELF electric and magnetic fields are uncoupled, what splits them and in what condition they will travel together(which is official definition of electromagnetic wave)?
 
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  • #4
user079622 said:
" Overall, extremely low frequency magnetic fields were evaluated as possibly carcinogenic to humans (Group 2B).."
So, should small permanent magnets carry a health warning?
 
  • #5
In my drawer "possibly carcinogenic" lies next to "we have no idea but we won't say 'safe' to avoid being sued".
 
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  • #6
user079622 said:
Does AC current in one wire produce EM wave or fluctuating EM field around it, does emf separated from source(wire) and propagate to space, so can we even call this "radiation" and consider this wire as " transmitter"?
I guess this is the "question" . Here is my anwer:
Any time a rfree point charge is accelerated it produces radiation. (Bremsstrahlung) If the wire geometry is chosen carefully then the contributions from many charges add coherently and this is called an antenna (transmitter) producing radiation. These fields are what we call light (or radio or ##\gamma## rays) and fall off slowly with distance .
user079622 said:
" Overall, extremely low frequency magnetic fields were evaluated as possibly carcinogenic to humans (Group 2B).."
Every piece of matter on the planet is a "potential carcinogen" so this is a statment devoid of content.
 
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  • #7
Thread closed temporarily for Moderation...
 
  • #8
@user079622 -- Please do not restart locked threads; that is against the PF rules.

user079622 said:
I just make copy of their text, I am not biologist or doctor and I am not interested in this discussion.
Then you should not have brought it up. Many things can contribute to developing cancer, and generally it depends on the exposure level.

user079622 said:
Does AC current in one wire produce EM wave or fluctuating EM field around it, does emf separated from source(wire) and propagate to space, so can we even call this "radiation" and consider this wire as " transmitter"?
This question has been answered well now for you, even though you seem not to be accepting it. Current that resonates in a wire can produce EM radiation that propagates away from the antenna structure, but ELF wavelengths are so long that for practical purposes you don't have any associated antenna structures. So ELF currents generate "near field" EM, where there is not an effective EM wave propagation.

This thread will remain closed. Please do NOT try to repost yet another thread on these topics without prior Mentor permission. Thank you to the folks replying in the thread trying to help out the OP.
 

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