If I'm not wrong, empty space (vacuum) has the greatest impedance amongst any material. Because [tex]\eta = \frac{1}{n} \sqrt {\frac{\mu _0}{\epsilon}}[/tex] if I'm not wrong and n=1 (smallest value possible) for free space. What does this mean that free space has a big impedance? It makes the greatest opposition to electromagnetic waves? I'm not getting the meaning of impedance in this case.(adsbygoogle = window.adsbygoogle || []).push({});

P.S.: I've searched in wikipedia, also wave impedance but didn't find any explanation about the meaning of it.

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# Impedance of free space/wave impedance

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