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Displacement
Current - and how to get rid of it Go to better
version with diagrams By I. Catt and M. F. Davidson and D. S. Walton, in Wireless World
dec78. To enable the continuity of electric current to be
retained across a capacitor Maxwell proposed a "displacement
current". By treating the capacitor as a special kind of transmission
line this mathematical convenience is no longer required. Conventional electromagnetic theory proposes that
when an electric current flows down a wire into a
capacitor it spreads out across the plate, producing an electric charge which
in turn leads to an electric field between the capacitor plates. The valuable
concept of continuity of electric current is then retained by postulating
(after Maxwell) [reference 1] a "displacement current", which
is a mathematical manipulation of the electric field E between the capacitor
plates which has the dimensions of electric current and completes the flow of
"electricity". This approach permits us to retain Kirchhoff's Laws
and other valuable concepts, even though superficially it appears that at the
capacitor there is a break in the otherwise continuous flow of electric
current. The flaw in this model is revealed when we notice
that the electric current entered the capacitor at one point only on the
capacitor plate. We must then explain how the electric charge flowing down
the wire suddenly distributes itself uniformly across the whole capacitor
plate. We know that this cannot happen since the charge cannot flow out
across the plate at a velocity in excess of the velocity of light. This
paradoxical situation is brought about by a fundamental flaw in the basic
model. Work on high speed logic design [reference 2] has shown that the model
of a lumped capacitance is faulty, and "displacement current" is an
artefact of this faulty model. The true model is quite different. Electric
current enters the capacitor [Note 1] through a wire and then spreads out across the
plate of the capacitor in the same way as ripples flow out from a stone
dropped into a pond. If we consider only one pie-shaped wedge of the
capacitor, see Figure 64 in http://www.ivorcatt.com/6_5.htm
or Fig. 1c in WW dec78, we can
recognise it as a parallel plate transmission line whose only unusual feature
is that the line width is increasing (and hence the impedance is decreasing).
The capacitor is made up of a number of these pie-shaped transmission lines
in parallel, so the proper model for a capacitor is a transmission line. Equivalent series resistance for a capacitor is
the initial characteristic impedance of this transmission line at a radius
equal to the radius of the input wires. Series inductance does not exist. Pace the many documented values for
series inductance in a capacitor, this confirms experience that when the
so-called series inductance of a capacitor is measured it turns out to be no
more than the series inductance of the wires connected to the capacitor. No
mechanism has ever been proposed for an internal series inductance in a
capacitor. Since any capacitor has now become a transmission
line, it is no more necessary to postulate "displacement current"
in a capacitor than it is necessary to do so for a transmission line. The
excision of "displacement current" from Electromagnetic Theory has
been based on arguments which are independent of the classic dispute over
whether the electric current causes the electromagnetic field or vice versa. Appendix.
.
. References. 1. 1. "History of displacement current", by Catt, Davidson and Walton, Physics Education, to be published early 1979. [jan99. The Inst. Phys. broke their contract with me to publish this article. It was eventually published in Wireless World in March 1979. (Essen F.R.S. told me Inst. Phys broke their contract with him to publish another article.)] 2.
2. "Crosstalk (noise) in digital computers",
I. Catt, IEEE Trans. EC-16, Dec. 1967, pp.743-763. [Note 1. 7oct02. The article discusses a capacitor as it is
always drawn in circuit diagrams, for instance the Harmsworth 1905
Encyclopaedia p1541. It has two circular plates, and the connecting wires
enter each plate at its centre. See Figure 64 at http://www.ivorcatt.com/6_5.htm . This idea of
the capacitor, which is for example a Leyden Jar, led Maxwell to propose "the extra
current", later called "Displacement Current". The truth is
different, a practical capacitor being as shown in Figure 65 of http://www.ivorcatt.com/6_5.htm . A true diagram, with electric current
travelling along the capacitor plate from one end to the other, could have
prevented Maxwell from proposing "Displacement Current" in the
first place, except that Maxwell was impartial [his treatise, art. 62.] over the possibility of instantaneous
action at a distance, so that electric charge (which was not particulate
during Maxwell's time, and had no mass,) might be able to jump from one end
of the capacitor plate to the other instantaneously. [This
article follows inexorably from the realisation that a capacitor is made up
of two parallel plates, entered at one end, exactly like a transmission line.
The realisation that classical electromagnetic theory treats displacement
current in a capacitor and in a transmission line in contradictory ways has
been ignored over the succeeding twenty years by every Reader in
Electromagnetism in every university in the world. They keep their heads
down. They take their salaries, but evade their duties. Ask your favourite
Reader in Electromagnetism, even from the University of North-West Redbourn, to make a written comment on this. Or ask the
author of a book on electromagnetic theory. One hundred and fifty pounds to
the first man who is successful! However, my money is safe. Not one of them
will want to lose his job, or have to modify his book, by commenting in
writing, and so betraying their and their colleagues' threadbare,
inconsistent dogma. They continue to pump the dogma down the throats of
bemused students. - Ivor Catt, jan99.] Second paper; "History of Displacement Current" Scandals
in Electromagnetic Theory; http://www.ivorcatt.com/28scan.htm Professor D. A. Bell, (HoD), M.A., B.Sc., Ph.D., F.Inst.P., F.I.E.E., saves
the day, using all his gongs. Then, silence for 15 years, which
continues. No more cracked chimes from Bell. May he R.I.P. The
intrepid D.A. Bell, Professor of Electrical Engineering at Hull University, F.Inst.P.,
F.I.E.E., tried to shore up a shaky structure with a dumb article in Wireless
World in aug79.; 16dec86.
Dear Mr. Catt, I am sorry, but I am unable to agree to the reprinting of any
of my Wireless World contributions in your proposed book; and in particular
this applies to "No Radio without Displacement Current" [Wireless
World, August 1979.] Yours sincerely, [signed] D. A. Bell. [Comment by I.C. " . and in particular ." presumably indicates that he refers to a particularly fine example of his writing. No throwing pearls before swine! IC 12feb99]
. 19.12.86.
Dear Professor Bell, Thank you for your letter dated 16Dec86. Is your reason
for refusal that you consider that you should benefit financially from the
re-publication of your contributions? Yours sincerely, Ivor
Catt. No it
is not. D. A. Bell, 24.12.86.
Dear
Professor Bell, Thank you for your letter dated 16Dec86, in which you refused
permission to reprint your part in the debate on electromagnetic theory which
has appeared in nearly every issue of Wireless World from 1978 to 1986. I
formally request that you reconsider your decision of 16Dec86. When
the new revolutionary theory of electromagnetism was first put forward by
Catt-Walton-Davidson in 1978-79 etc., you took it upon yourself to carry the
flag for the traditionalists opposing our new theory. What you wrote in your
article "NO RADIO WITHOUT DISPLACEMENT CURRENT" was damaging to us
and to the advance of science, because your very senior position in the academic
hierarchy in ways particularly relevant to electromagnetic theory (you were
ex-Reader in Electromagnetism in Birmingham University) tended to mask the
crass ignorance you and your Establishment colleagues (e.g. Prof. Brown [past
President of IEE] of Imperial College,
now Marconi) showed about the subject that was generating your salaries. [I heard of a particularly dirty trick by Brown. He went around saying Catt was a genius - for instance to Professor Clarricoat. This was perfect cover for his organisation, the I.E.E., of which he was then President, totally suppressing Catt then and for the next few decades. Catt had to be suppressed or his theoretical advances would show up their ignorance. It was difficult enough for them to keep up appearances in a stable environment. IC 12feb99.] If you
do not change your position, I shall say in my book that you refused to have
your article published. Yours faithfully, Ivor Catt
20 12 86
Professor
D. A. Bell, 87 East End, Walkington, Beverley, North
Humberside HU17 8RX Dear
Professor Bell, Your refusal to allow me to reprint your Wireless World
article NO RADIO WITHOUT DISPLACEMENT CURRENT was unexpected, and I enclose
an example of the pages which have already been printed containing your
article, on the assumption that you would present no difficulty. Unless you
withdraw your refusal, these pages will have to be reprinted, which will be
expensive. This will leave a space in the book, because it is far too late to
renumber all the pages and reprint the whole book. You are very welcome to
write something new to replace your article. I calculate that with my typing
it should run to either less than 1600 words (small, orthodox type) or less
than 1200 words (this print size). I am offering
space in the book I am making, which book contains all my articles in
Wireless World on e-m theory from 1978 to 1986. The space would be that
caused by your refusal to allow me to insert your article NO RADIO WITHOUT
DISPLACEMENT CURRENT. You would also be welcome to write less than the 1200
words mentioned above. Should
you be concerned that I might in the end refuse you space in my book after
you had made the effort to produce the thousand words or so, I plan to defer
to the Editor of Wireless World as the arbiter over fair play. I am therefore
sending him a copy of this letter plus my previous letter to you. You
will appreciate that membership of the I.E.E. binds you to the Rules of
Conduct for a member, which include doing everything within your power to
enable discussion of the fundamentals of the subject. You
will also be welcome to the usual author royalty on books sold pro-rated in
proportion to the pages you contribute divided by the total pages in the
book. I offer the usual higher limit of royalty, which is 15% of retail. Yours
sincerely, Ivor Catt 29.12.86 Dear
Mr. Catt, DISCIPLINARY
PROCEDURES Thank
you for your letter of 18 March. I will arrange for an Investigating Panel to
consider your complaint against Professor Bell. So that
there shall be no confusion could you please confirm to me that the cause of
your complaint is Professor Bell's refusal to permit you to republish the
article which he wrote on "No Radio without Displacement Current"
and which appeared in Wireless World in August 1979 in a book which you are
preparing. Yours
sincerely F G Helps Chairmen of the Investigating Panel, Institution of
Electrical Engineers, Savoy Place, London WC2R 0BL 23mar87 Dear
Dr. F G Helps, Thank
you for your letter dated 23 3 87. You
correctly state the cause of my complaint. I
enclose copies of Bell's letter to me dated 15 3 87 and my reply dated 22 3
87. Should
Bell agree to option [c] in my 22Mar letter [You will allow
reprint of your Aug79 article in future editions of the book], I would have to consider withdrawing my complaint.
However, in view of his item (3) in his 15Mar letter [My
decision not to comment is final and I will not enter into any further
correspondence], we can dismiss
that possibility. Should
Bell assert that his Aug79 article is not a response to my Dec78 and Mar79
articles, I plan to produce; 1 Copies of letters in Wireless World in which the
debate between Bell and me (or my co-authors) was continued. 2 Signed confirmation from
editor(s) of Wireless World and other experts that Bell entered into a
published dialogue with me on the question of the validity of my theories,
and that he represented the traditional Establishment position. The
cause of my complaint is narrowly stated in your letter dated 23Mar. However,
further documentation will help the Panel to understand the Intent behind his
professional misconduct, his Intention to persist in misconduct, and the
extent of the damage which has already resulted from his misconduct and the
future damage which will accrue unless he changes his behaviour. My
18Feb letter shows in the narrow sense that Bell is in breach of IEE Rules of
Conduct. However, the Rules of Conduct themselves point to a broader approach
to such a situation; "A code of professional conduct designed to cover
all eventualities must necessarily be written in general terms expressing
broad ethical principles
.." Broadly,
it is necessary to show that in the narrow sense, Bell has breached the Rules
of Conduct if he is to be disciplined. Once that is so decided, then his punishment should be commensurate with the
broader, ethical issues raised by his behaviour. I find it difficult to
conjure up behaviour by someone placed as he is, with major resonsibility for furthering the Art and enabling open
communication towards that end, that could be more damaging to advance in
Science and Engineering, and in breach of the discipline which is central to
the interests and responsibilities of the Institution of which he is a
Fellow. From his position, he could not have behaved in a manner more
damaging to advance in electromagnetic theory. Yours
sincerely, Ivor Catt 26 3 87 cc D A Bell The
I.E.E. Disciplinary Committee later reported to me that their decision was
unanimous in favour of D A Bell. - Ivor Catt,
6feb99. The IEE
for its own part stood its ground for a further decade, insisting that Ivor Catt's contributions to e-m did not exist, until
they published a slamming denigration in an IEE journal of Catt's 1994 book Electromagnetism by one B. Lago, see http://www.ivorcatt.com/9_review.htm . (B Lago's
only function in life seems to be to lob a grenade at Catt's theories once
every 20 years. Apart from that, he doesn't appear to exist. Nobody seems to
have met him.) However, during that period '85-'95, although for another ten
years embargoing Catt's e-m theory, they began, shortly after the misconduct
by Bell, to publish commentary on the major projects to develop the
"Catt Spiral" WSI invention with funding by the Brit. Govt.,
Unisys, Fujitzu, Tandem, SGS. (All attempts by Catt
to publish on the matter have however always been rejected by the IEE.) The
IEE's doyen Dr. A. Lynch then broke rank, and the IEE published the joint
Lynch-Catt paper on e-m, discussing the Catt Anomaly, in 1998. It is on this
website. However, IEE members still are shielded from my dec78 paper; the one
attacked by Bell. I predict that the IEE will risk giving it members access to the dec78 ideas in around the year 2015.
However, we have to get past a lot more ignorant noise before that happy day. Ivor Catt feb99.
. IC
15feb99. This is not just another run-of-the-mill scandal like the BSE
suppression. I
decided that both I.E.E. officials and others should be able to read today's
appraisal by my two co-researchers of the significance of the advances we
have made, which have been suppressed by individuals like Bell and by
institutions like the IEE and the InstPhys. The
first reply was David; "In
so far as one can be a competent judge of one's own work - 'very
significant'."
. Dear Ivor, Recently
I spent three hours talking to two of our senior technicians on em theory. They were spellbound as I went through all the
concepts. It reminded me of the power of a coherent theory, which, in
reality, is incredibly sound and has a profound impact on those that listen
with an open mind. It did me a lot of good. - Malcolm, feb99. Dear
Malcolm, It is a
great privilege to go through the experience that Ivor,
Malcolm and David went through. We have experienced something that very few
men have in the whole of history. We were at the hinge of history. You will
never forget the day when I sat before the window with you at my right, and
said "Then electric current goes." The evening before Walton had
said to me "Then that's the end of Displacement Current." These are
the turning points in the history of mankind. You were there. Dave was there.
I was there. We are very privileged. I started calculating the way energy
goes from capacitor to inductor and back. Remember the excitement when it
turned down again, and so it looked as though it would simluate
a sine wave with lots of small steps. Then I
had to phone Dave. Henry V
said; "I was there, on St. Crispin's Day." There were thousands of
them. But at the end of displacement current and at the end of electric
current, there were only the three of us very privileged adventurers. "He that outlives this day, and comes safe
home, Will stand a tip-toe when this day is nam'd, And rouse him at the name of Crispian. He that shall live this day, and see old age, Will yearly on the vigil feast his neighbours, And say 'Tomorrow is St. Crispian'. Then will he strip his sleeve and show his scars, And say 'These wounds I had on Crispian's
day'. Old men forget; yet all shall be forgot, But he'll remember, with advantages, What feats he did that day. Then shall our names, Familiar in his mouth as household words - Harry the King, Bedford and Exeter, Warwick and Talbot, Salisbury and Gloucester- Be in their flowing cups freshly rememb'red. This story shall the good man teach his son; And Crispin Crispian shall
ne'er go by, From this day to the ending of the world, But we in it shall be remembered- We few. we happy few, we band of brothers; For he today that sheds his blood with me Shall be my brother; be he ne'er so vile, This day shall gentle his condition; And gentlemen of England now a-bed Shall think themselves accurs'd
they were not here, And hold their manhoods
cheap whiles any speaks That fought with us upon Saint Crispin's day. The
dates are writ big in history. David
moved fast. On
26may76 David Walton had said to Catt; 'So that gets rid of displacement
current.' Then, on 27may76, Catt
said to Davidson; "The electric current goes." These were truly St.
Crispin's Day, but shared by a tiny group of three. A very favoured few, a
happy few. I have before me a letter from Walton, unnoticed
until today; "27may76.
Your phone call last night was very exciting. I think I see the transformer
now in terms of crosstalk ...." How
could such as we have been more favoured? I think
you should show this to your technicians, who were so much impressed by your
talk on e-m. Can we get them to glimpse the grandeur of the experience? - Ivor, feb99. |
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