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Roy Lewallen wrote:
I've explained how I calculated how much energy is stored in the transmission line. The movement of energy within the line is complex; in the abbreviated analysis I've had time to do so far, it sloshes back and forth in regions within the line. From where to where at what speed? Sloshing sounds like a violation of the conservation of momentum. What force changes the direction of the slosh? How much efficiency is lost in the energy required to change sloshing directions? It does not travel in waves of average power, bouncing back and forth, and believing so isn't necessary in order comply with energy conservation. Nothing RF travels in waves of average power. Average power is just our simplified shorthand way of dealing with it. The AC voltage is equal to the RMS value at only two points in the cycle. Sticking with instantaneous values for everything AC would complicate things beyond belief. The values of voltage in your chart were RMS (average) values. You don't seem to have a problem dealing with RMS values of voltages and currents. Why do you have a problem with average power associated with those average RMS values of voltage and current. Your view of power and energy is oversimplified, and it fails when you're pressed to explain what happens at the interface between the line and the outside world. What is located at that interface? Anybody is pressed to explain things when the source impedance is unknown and cannot be measured. Momentum is conserved in mechanical elastic collisions, but not in inelastic ones, e.g., when energy is being extracted. I wouldn't begin to try to apply this to a transmission line, but I see it doesn't bother you. Hecht, in "Optics" certainly applies it to EM waves. RF EM waves differ from light waves only in frequency. Conservation of momentum is a cornerstone of EM light physics and is included in the rules of relativity. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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