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Reply from Nobel Prizewiiner Brian Josephson |
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Simplified version From: Brian Josephson
On 4 May 2007 17:13:12 +0100 ivor catt wrote: "[Look at] http://www.electromagnetism.demon.co.uk/cattq.htm " - Ivor Catt Dear Ivor, Your animation is very helpful in thinking about the issue (and I see it can be halted at any time using the browser's 'stop loading' button, which is useful also). On pondering it I conclude that the 'Josephson view' remains correct, while the alternative is based on the incorrect idea that the electrons would have to travel at the speed of light if they arrived along the 'east west' axis. The speed of the wave front (which is propagated by the em fields, not the electrons) does not have to be the same as the drift speed of the electrons at all, and the very high density of electrons means that they do not have to go very fast to make up the current. It equally does not follow that the charge does not (taking due account of the skin effect reside on the surface. But I think this has all been gone over in the past (viz. the fact that when you turn on a tape connected to a full hose the water starts flowing immediately (or at least as immediately as the propagation of the pressure wave allows)). Nevertheless Pepper's point about plasma frequencies is relevant. It has been noted earlier in the discussion that the usual transmission line theory neglects the inertia of the electrons, in the absence of whuch the current would start up instantaneously as the pulse passed. This is normally OK as frequencies are low compared with the plasma frequency, but my guess is that the inertia would affect the phase velocity of transmission of the wave at a given frequency, making it frequency dependent, meaning dispersion (resistive losses will do this as well), spreading out the discontinuity. It also means there is a longitudinal component of the E-field as well (there is in the idealised case also, but there it is an infinite field at the discontinuity). I must stress that this is all 'thinking in my head' and so is 'guaranteed unreliable'. I will send a copy of this to Pepper. If he does not disagree with anything then it may be safely assumed that the Catt anomaly is an anomaly no longer. Regards, Brian Josephson PS: feel free to post the above to your list. @@@@@@@@@@@@@@ From: Brian Josephson Pepper has confirmed that he agrees with my analysis. Brian J. @@@@@@@@@@@@@@ ----- Original Message ----- --On 29 May 2007 00:06:56 +0100 ivor catt wrote; Is the Master of Trinity willing to elicit a clear statement from Pepper as to whether he now agrees with Josephson, Not necessary -- Pepper has told me he agrees with what I wrote to you a few weeks ago [above] , which I hope you have distributed to your list. In summary, there are two things going on (as I explained) when the finite mass of the electron is taken into account. Initially, I focussed on one (the low frequency case) where the mass can be ignored, and he focussed on the high-frequency aspect where plasma type effects are relevant. Thus there is no contradiction, and we are agreed that both aspects are needed for a full treatment. Hope that helps. [- BJ] Or does the whole of Trinity, Newton's college, think that the question of where the charge comes from on the conductors when battery lights lamp is unimportant? I follow Einstein. Importance is a relative concept. - Brian J.
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--On 29 May 2007 09:54:27 +0100 ivor catt <icatt@btinternet.com> wrote: [Catt's First Question] 1 "The Catt Question" does not contain frequency. It is about the state before and after a logic step has gone by. Electromagnet6ic theory has to cope with the digital age. In the context of "The Catt Question", the only event which ever happens is one positive change in voltage between the two conductors. Both before and after this instantaneous transition, there is no change. Unless you are going to wait infinite time, in which case the charge does come from the battery, frequency considerations do enter.
No. How can lateral movement of a fixed amount of electric charge make it able to terminate more electric flux than before? If that means what it seems (to me) to mean, it doesn't. [ 31May07. Clarification. "Lateral movement means movement of charge from the south, as asserted by Pepper in 1993. "the disturbance propagates at right angles to the direction of propagation of the wave"] PS this exchange will be discontinued as
soon as I have more important things to do with my time (importance
is relative).
-- Prof. Brian D. Josephson
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