cogreslab said:
Polarization.
Anyone can set out a description of polarisation, just with a little effort and Google. Here is a simple description (copied from Google, not by me):
Except you it appears, you have to steal someone else's work and present it without acknowledging the true source. Pathetic.
And I am perfectly familiar with polarization thank you. I don't need you or anyone else to tell me about the polarization of electromagnetic waves. What I REQUESTED was that you explain your claim about "polarized magnetic fields". Magnetic fields are NOT electromagnetic waves - if you don't even know the difference you are even more ignorant than I believed (which is certainly pushing boundaries of belief as it is).
So this is noted as yet another evasion, and another claim you apparently can't back up.
cogreslab said:
Prag: you still have not conceded that both RF and ELF waves (or fields to which they give rise) can penetrate the body. You said they couldn't and you are wrong.
As for SAR, its formula includes an expression of the internal electric field, just as I said. See my subpage on our website for the formula. There is no way SAR is not defined by an (internal) electric field.
Conceded? RF and ELF
WAVES? As for RF WAVES, I do recall saying that the skin effect would significantly oppose penetration of RF many posts ago. That is true. So I can't see what there is to "concede". Secondly, I don't recall making any statement to the effect that ELF WAVES couldn't penetrate the body. I require you to prove that assertion. I said, quite clearly, many times that ELF ELECTRIC FIELDS will not penetrate the body to any significant extent. Yes, there IS a major difference. The "fields to which the waves give rise" doesn't make any sense.
ELECTROMAGNETIC WAVES (RF
OR ELF) are NOT ELECTRIC FIELDS.
Yet another straw man argument?
SAR is an estimate of POWER absorbed as I explained. It is NOT a measure of "electric field", although electric field is considered in one of the forms of the calculation. So is conductivity. You multiply the two together (well, E^2 * conductivity / tissue mass density).
BUT, the actual electric field in tissue depends on the impedance of the tissue AND the source impedance of the field as well. A low impedance in tissue and a high impedance source for example means that the E field will be reduced substantially in magnitude when it hits the tissue. And any impedance mismatch will cause reflection as well.
Now, the important point is this: the electric field (in an RF ELECTROMAGNETIC WAVE, NOT an isolated electric field) is PRESUMED (for the purposes of calculation) to provide the drive that mobilises a current. The POWER that is absorbed, is generated as a result of the CURRENT that the field is PRESUMED to cause. Which depends on a series of impedances as I have said. BUT if I wanted to calculate the SAR I could just as easily use the magnetic component and refer only to currents without ever MENTIONING electric field at all! So the fact that the electric field appears in one form of the equation tells me next to nothing about the electric field itself.
(For the benefit of people who DO understand basic electrics, I could just as easily use I^2 * R to calculate power as V^2/R. R will actually be complex, (Zr + i * Zi) in the case of a real world impedance.)
So the SAR can not in any way be considered a "measure" of electric field strength. Because the POWER depends entirely on the electric field strength AND the impedances in COMBINATION, NOT the electric field in isolation. (Or the magnetic field and the impedances if I wish).
In any event, the electric field referred to is the electric VECTOR COMPONENT of an ELECTROMAGNETIC WAVE, it is NOT a pure electric field.
But the problem, as you keep illustrating, is that you don't really understand what either a field or a wave actually is. And you are confusing a mathematical model with a real field.
Edited to add: I don't recall anyone denying that RF would penetrate the body to SOME extent. In case that wasn't clear from the above. RF is NOT ELF.