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Request to Nobel Prizewiiner Brian Josephson
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| [copy of letter sent by slomail Ivor Catt, 121 Westfields, St. Albans AL3 4JR 1 January 2007 second copy sent slomail Recorded Delivery with ** .... ** added on 25 April 2007 Trinity College, Cambridge, CB2 1TQ ........<bdj10@cam.ac.uk> Dear Professor Josephson, Please would you say either that; 1. The Catt Question is unimportant, or that 2. You after all agree with Sir Michael Pepper on The Catt Question , or that 3. A Conference should be held on The Catt Question. ** [Added 25 April 2007]. Should Cambridge Undergraduates on the relevant courses be informed that the fundamentals of electromagnetic theory are unresolved; that it is not clear where the negative charge on the bottom conductor comes from?... ** I look forward to your reply, which will be posted on this web page. Yours faithfully, Ivor Catt
The Conference ; A previous Josephson Conference
@@@@@@@@@@@@@@ From: "Brian Josephson" <bdj10@cam.ac.uk>
http://www.electromagnetism.demon.co.uk/cattq.htm Dear Ivor, Your animation [ 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. -- * * * * * * * Prof. Brian D. Josephson :::::::: bdj10@cam.ac.uk @@@@@@@@@@@@@@ From: "Brian Josephson" <bdj10@cam.ac.uk> Pepper has confirmed that he agrees with my analysis. Brian J. -- * * * * * * * Prof. Brian D. Josephson :::::::: bdj10@cam.ac.uk
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