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LarryS

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- TL;DR Summary
- Do capacitance and inductance have meaning for just an EM Wave in free space, in the absence of physical wires and currents?

According to Maxwell’s Equations, the speed an EM plane wave in free space, far from its source, is determined by the electric constant, ε0, and the magnetic constant, μ0, such that c = 1/√( ε0 μ0).

The

Do the quantities of capacitance and inductance have any meaning for an EM wave in free space far from its source? Can their definitions be generalized beyond physical wires and currents?

The

**of ε0 are capacitance per unit length and the units of μ0 are inductance per unit length. Those two quantities have real meaning for a transmission line consisting, say, of two parallel perfectly conducting wires. Together they define the impedance of such a transmission line. That impedance seems to explain the finiteness of the transmission speed, the speed of light.***units*Do the quantities of capacitance and inductance have any meaning for an EM wave in free space far from its source? Can their definitions be generalized beyond physical wires and currents?