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Jim Kelley wrote:
Actually it's just a quote from an optics book describing, among other things, how a field can cross a boundary without energy necessarily flowing across it. It happens to be the same thing I've been trying to explain to you. But nobody cares about your *NET* energy quotations. This thread is about the energy components underlying the steady-state solution. What is it about that statement that you don't understand? If you want to discuss net energy, please start another thread. I searched the entire thread. Not one mention of photons dematerializing or rematerializing. It was in another thread, Jim. Actually you have it backwards. If energy had been reflected, the forward waves would have given up their energy to the reflected waves. The forward wave *DOES* give up (Pfwd*|rho|^2) energy to the reflected wave at a mismatched load. I'm sorry to pull an argumentum ad populum on you but everybody on this newsgroup knows that except you. The reflected waves only give up their energy in a sense by not taking it in the first place. More Bafflegab. Please research the reflected power Poynting vector from the previously provided reference of Ramo and Whinnery and get back to us. P1 and P2 are the only terms in the equation, Cecil. Which leads you to believe that P1+P2 P1+P2? What is it about destructive interference energy feeding energy to the constructive interference event that you do not understand? Assume Wave(1) is associated with P1 and Wave(2) is associated with P2. P1 + P2 + 2*Sqrt(P1*P2) is the proper equation when Wave(1) and Wave(2) are in zero phase. On the other side of the impedance discontinuity we have a similar equation: P3 + P4 - 2*Sqrt(P3*P4). Agree so far? Pref1 = P3 + P4 - 2*Sqrt(P3*P4) = zero reflected power toward the source. So P3 + P4 = 2*Sqrt(P3*P4) = 100% destructive interference during wave cancellation, i.e. Wave(3) and Wave(4) are destroyed. The destructive interference equals the total of P3+P4 *because* those waves were destroyed. Wave(3) and Wave(4) give up their combined energy components as destructive interference energy. Hecht tells us that the magnitude of the destructive interference must equal the magnitude of the constructive interference. Guess what? He is right! |2*Sqrt(P3*P4)| does indeed equal |2*Sqrt(P1*P2)| and we can simply say that according to Hecht, |2*Sqrt(P1*P2)| comes from |2*Sqrt(P3*P4)|. The destructive interference event supplies the power for the constructive interference event. I'm getting tired of typing the following quote from _Optics_, by Hecht: "The principle of Conservation of Energy makes it clear (to everyone except Jim) that if there is constructive interference at one point, the 'extra' energy at that location must have come from ... destructive interference somewhere else." I don't know how Hecht could have said it any clearer. The constructive interference energy is supplied from the destructive interference event. So the valid equation becomes P1+P2+2*Sqrt(P3*P4) = P1+P2+P3+P4, i.e. all the power in the entire Z0-matched system winds up flowing toward the load but we already knew that. How you can argue with that fact is simply unbelievable. What he's saying is that you can't have one without the other. Yes, and the destructive interference event *supplies* energy to the constructive interference event. It certainly cannot be vice versa as you are attempting to imply. Hecht was very careful to say that constructive interference requires a source of energy from a destructive interference event. See above quote. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =----- |
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