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From: Alan G3NOQ
Date: 02 Jan 2003
Time: 03:38:41
Remote Name: 20.138.254.2
Bill - Happy New Year to you. The mathematical demonstration of displacement current you asked for is very simple - so simple you put it in your message and failed to see it. It is just epsilon.dE/dt like you said - that's the diplacement current density at any point. It's that because Maxwell said it is, and nobody has found a reason to say otherwise. . . . It is important to realise that it is a quantity that exists at any point in space where there is a changing electric field, so it does not matter whether the point is inside a capacitor or a transmission line, or next to a power cable, or in the near or far field region of an antenna. . . It exists because we choose to say it exists, and it earns its keep by providing explanations for strange phenomena like radio waves. . . Now you are free to say it doesn't exist, but I think you will quickly get into difficulty if you go down that road, because then you will not be able to explain radio waves . . . . 73s, Alan