Can I consider vacuum as a space free from em waves or gravity waves ?
If not why such a space can't exist ?
And what do we mean by electric impedance of vacuum to to 273 Ohm or something like that?
Regards
Nityananda Das
This doesn't have anything to do with ``Free Will''. Vacuum impedance is exactly what it means: between two points in vacuum, there's a resistance, in the presence of static fields, an impedance in the presence of time-dependent fields, that has a finite value. Its expression is (μ0/ε0)1/2 that has the correct dimensions and its numerical value, in SI units is about 377 Ohms; (-273 is the numerical value of absolute zero in Celsius units).
What is meant by it is the same thing as is meant by impedance or resistance of any material. Electric and magnetic fields can propagate in vacuum, after all.
Vacuum is ``free'' from electromagnetic waves-they propagate in it, without modifying it, unless they're strong enough to create particle-antiparticle pairs, which is called ``dielectric breakdown''.
The concept of impedance of the vacuum is wrong if we think that this physical quantity is related with losses, i.e. there is a transformation of electromagnetic energy in irreversible heat. It is only a play between electromagnetic units. Therefore all the deductions from it for the fields of the Universe is non sense.
Respected Nicolis,
I am sorry that I have written 273 ohm, instead of 377 ohm .
Thank you for the correction.
But thing is confusing. What does it mean by this small impedance of vacuum?
And the othe is as you say that dilectric breakdown creats pair of particle and anti particles.
What is the vacuum breakdown Electric field ?
Regards
Nityananda Das
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